Age-specific prevalence and causes of blindness and visual impairment in an older population: the Rotterdam Study

Annual Trend of Myopia and High Myopia in Children in Japan: A Nationwide Claims Database Study

Purpose

To determine the prevalence and annual trend of the number of incident cases of myopia and high myopia in children.

Design

A nationwide, comprehensive claims database study.

Participants

Of 15 million children aged ≤14 years, those covered by the universal health insurance were included. The validation study of the claims-based definitions of myopia and high myopia was conducted using 14 654 individuals aged ≤14 years recruited from 11 diverse medical facilities.

Methods

This study comprises a national claims database analysis and a multicenter validation study. Data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, which contains the nationwide health insurance claims data, were assessed. All individuals aged ≤14 years were reviewed, and children with existing and new onset of myopia or high myopia between January 2011 and December 2020 were identified. A validation study was conducted by reviewing electric medical records.

Main Outcome Measures

Prevalence of myopia as of October 1, 2020, and the annual number of incident cases during 2014 to 2020.

Results

According to the 2020 population census, there were 14 955 692 children aged ≤14 years. Among them, 5 498 764 patients had myopia on October 1, 2020, corresponding to a prevalence of 36.8%. The number of incident cases of myopia was highest at 8 years of age, increasing from 853.3 cases/person-year in 2015 to 910.7 cases/person-year in 2020. The prevalence of high myopia increased with age, peaking at 0.46% among children aged 10 to 14 years; the number of incident cases annually increased in 5- to 9-year-olds and 10- to 14-year-olds. In the year 2020, when the coronavirus disease 2019 pandemic occurred, a discontinuous increase in the number of incident cases of myopia was observed in children aged 8 to 11 years, not 12 to 14 years. The overall sensitivity and specificity of the claims-based definition for myopia were 88.5% and 79.2%, respectively, whereas the corresponding values for high myopia were 41.6% and 99.8%.

Conclusions

This first comprehensive nationwide study revealed the prevalence and annual incidence trends of myopia and high myopia. These findings complement the results of previous high-quality cohort studies, offering a more comprehensive understanding of myopia trends.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Twelve month refractive and axial length changes in the Israeli refractive error, activity, and devices (iREAD) study

The Israel Refraction, Environment, and Devices (iREAD) is a longitudinal study assessing myopia risk factors in three groups of boys with distinct lifestyles. Ultra-Orthodox (N = 41), Religious (N = 53), and Secular (N = 41) boys (ages 8.6 ± 1.5 years) had eye exams at baseline and 12 months, including cycloplegic autorefraction and axial length. Ocular history, education, near work, and electronic device use were assessed. Time outdoors and physical activity were measured objectively. At 12 months, myopia prevalence increased from 32 to 40% (P = 0.02), with no group differences (P > 0.05). The Ultra-Orthodox group had a more myopic spherical equivalent refraction (SER) at baseline and 12 months than the Religious and Secular groups and more myopic shift at 12 months (P < 0.05 for all). The Ultra-Orthodox group spent less time using electronic devices, more time in school, read at an earlier age, and had higher parental myopia (P < 0.01 for all). Time outdoors and activity did not differ between groups (P > 0.05 for both). In univariate and multivariate analyses, group and parental myopia were associated with greater myopic shift of SER and axial elongation (P < 0.05). In conclusion, risk factors associated with greater myopia progression included being part of the Ultra-Orthodox educational system and number of myopic parents and not screen use.

Long-term visual outcomes of patients with neovascular age-related macular degeneration treated with anti-VEGF therapy lost to follow-up

PURPOSE

To evaluate the long-term visual outcomes of patients with neovascular age-related macular degeneration (AMD) who were lost to follow-up (LTFU) during treatment compared with those with continuous follow-up (CFU).

METHODS

A retrospective study was conducted on patients diagnosed with neovascular AMD who received anti-VEGF therapy from 2010 to 2022. The patients were classified into the long-term LTFU group (LTFU for more than 6 months), the short-term LTFU group (LTFU for 2 months to less than 6 months), and the CFU group. We conducted a comparative analysis of baseline characteristics, factors related to visual prognosis, and differences in the occurrence of severe vision loss.

RESULTS

A total of 169 patients were classified into 43 in the long-term LTFU group, 57 in the short-term LTFU group, and 69 in the CFU group. The mean follow-up duration was 57.12 ± 31.68 months. There was no significant difference in baseline visual acuity (logMAR) among the long-term LTFU, short-term LTFU, and CFU groups (0.76 ± 0.54, 0.68 ± 0.51, and 0.72 ± 0.54, respectively; P = 0.734). The final visual acuity was significantly lower in the long-term LTFU group (1.12 ± 0.79) compared with the short-term LTFU group (0.65 ± 0.62) and the CFU group (0.65 ± 0.56) (P < 0.001), and the change in visual acuity was significantly greater in the long-term LTFU group (0.36 ± 0.69) compared with the short-term LTFU group (-0.03 ± 0.64) and the CFU group (-0.07 ± 0.58) (P = 0.001). Long-term LTFU was significantly associated with changes in visual acuity from the baseline to the final visit (P = 0.002) and severe vision loss (P = 0.002).

CONCLUSION

In patients with neovascular AMD, those LTFU for more than six months during treatment had worse long-term visual outcomes compared to those with regular follow-up or shorter LTFU durations.

Insignificant difference in medication adherence to dyslipidemia drugs between visually impaired and non-disabled people in South Korea: A nationwide cohort study using claims records

Incidence of visual impairment (VI) and dyslipidemia is increasing with aging. Although good medication adherence (MA) is a crucial factor in achieving therapeutic goals for dyslipidemia, there is a paucity of studies measuring MA in the visually impaired with dyslipidemia. We investigated whether patients with VI had worse MA to dyslipidemia drugs than non-disabled people and determined the factors affecting MA among patients with VI. Data on dyslipidemia patients with VI were extracted in 2017 from the sample cohort database of the National Health Insurance Service. MA to dyslipidemia drugs was measured for two years based on the proportion of days covered (PDC). Conditional logistic regression analysis was performed to analyze the effect of VI on good MA (PDC ≥0.8). The VI group (0.860) had a larger PDC than the non-disabled group (0.850). The adjusted odds ratio (aOR) for good MA among VI vs. non-disabled individuals was statistically insignificant (1.137, 95% confidence interval:0.958-1.350). Significant factors for poor MA in the VI group were younger age (aOR for 20-39 vs. ≥75 years old: 0.124), lower income (aOR for 9-10th decile (rich) vs. 1-4th decile (poor): 1.771), shorter duration of dyslipidemia (aOR for 1-4 vs. 15 years: 0.416), having lower-level providers sas their main providers (aOR for clinics vs. general/tertiary-care hospitals: 0.545), and having mental diseases (aOR: 0.679). Patients with VI did not have worse MA than non-disabled patients taking dyslipidemia medication.

The Screening Visual Complaints questionnaire-acquired brain injury: Development and evaluation of psychometric properties in a community sample

PURPOSE

Visual complaints are a common consequence of acquired brain injury (ABI). Yet, they may be overlooked in clinical practice. The present study aims to develop a screening instrument for assessing visual complaints in individuals with ABI and evaluate its psychometrics properties in a community sample.

METHODS

We constructed the Dutch Screening Visual Complaints questionnaire-acquired brain injury (SVCq-abi), a self-report 23-item questionnaire. A Dutch community sample of 1159 participants (Mean [SD] age, 60 [16] years) completed the SVCq-abi and other questionnaires on visual disturbances, executive functioning, mental health, and autistic traits. Confirmatory factor analyses were performed for 5 models (1-factor, 3-factor, 5-factor, second-order, and bifactor) on a random split of half of the sample, and cross-validated on the other half. In addition, we evaluated floor and ceiling effects, scale reliability, test-retest reliability, as well as convergent and divergent validity.

RESULTS

A 5-factor structure of the SVCq-abi was adopted which showed an excellent model of fit, with all item loadings exceeding 0.5. The SVCq-abi subscales demonstrated various floor effects, acceptable scale reliability, moderate to good test-retest reliability (ICC = 0.65 to 0.73), along with sufficient convergent (r2 = 9% to 32%) and divergent validity (r2 = 2% to 13%).

CONCLUSIONS

The SVCq-abi shows fundamental psychometric properties and the factor analysis provides support for a 5-factor structure. Further validation of the SVCq-abi in individuals with ABI is essential.

Exploring the Effects of Age at Menarche and Pregnancy on Myopia

PURPOSE

Associations between age at menarche and myopia have been observed in studies that included older women. Furthermore, pregnancy-related hormone surges in young women are associated with short-term changes in refractive error, although the long-term effects are less known. This study explored associations of age at menarche and parity with refractive error and ocular biometry in young women, and the relationship between age at menarche and refractive error in middle-aged adults for comparison.

METHODS

Community-based young women underwent eye examinations at 20 and 28 years old. Information on age at menarche and parity were collected prospectively. The older cohort underwent an eye examination and information on age at menarche was self-reported retrospectively. Cross-sectional associations between age at menarche and myopia were explored in both cohorts. Associations between parity and 8-year longitudinal change in refractive error measures were explored in the young cohort.

RESULTS

The cross-sectional analyses comprised 429 young (age 18-22) and 1,818 older (age 46-69) women. No associations were found between age at menarche and myopia or ocular biometry measures in either cohort. The longitudinal analysis (n = 269 women) revealed that for each pregnancy carried to full term, there rate of lens thickening increased by 0.004 mm/year (95% CI = 0.002-0.007). No other associations between parity and refractive error or ocular biometry were found.

CONCLUSION

There is no association between age at menarche and myopia or its related measures. While pregnancy was associated with thicker lens in the long term, there is no lasting effect on refractive error.

Age-matched analysis of axial length growth in myopic children wearing defocus incorporated multiple segments spectacle lenses

BACKGROUND/AIMS

Defocus incorporated multiple segments (DIMS) spectacle lenses are known to be able to inhibit axial length (AL) growth in myopic children compared with single vision (SV) spectacle lenses. However, it is not known whether AL growth is sufficiently inhibited to achieve the treatment goal of physiological AL growth.

METHODS

Of the data already collected in 2014-2017 by Lam et al, the AL growth with DIMS and SV spectacle lenses was re-evaluated according to the age-matched myopia control system. The individual AL growth after the first year of treatment of each eye was plotted against the corresponding age of the same time point in a colour-coded scheme. The two treatment groups were further subdivided based on their age and their baseline AL.

RESULTS

Overall, 65% (61% of male, 70% of female) of eyes with DIMS spectacle lenses and 16% (16% of male, 16% of female) of eyes with SV spectacle lenses are within range of physiological AL growth rate. Median AL growth rate of eyes with DIMS spectacle lenses is also within the range of physiological growth. In the subgroups, eyes with DIMS spectacle lenses were also superior to the ones with SV spectacle lenses regarding this treatment goal. Of the children with SV spectacle lenses, older children and children with eyes with high baseline AL were least likely to achieve physiological AL growth rate.

CONCLUSIONS

DIMS spectacle lenses can bring the AL growth rate of myopic children to the level of physiological AL growth rate, indicating 100% reduction of excessive myopic AL growth, independent of age and baseline AL. Older children and children with eyes with high AL have the risk to have increased AL growth without treatment.

Trends in Geographic Distribution of Visual Disability - United States, 2010-2019

PURPOSE

We aimed to describe changes in the geographic distribution of self-reported visual impairment (VI) over the last decade (2010-2019) in the U.S.

METHODS

Our study was an analysis of publicly available data collected between 2010 and 2019 from the Census Bureau American Community Survey.

RESULTS

The mean overall prevalence of self-reported VI from 2010 to 2019 was 2.31% in the United States, and there was a significant increase in VI over the past decade from 2.25% in 2010-2014 to 2.37% in 2015-2019 (p < .001). VI was significantly higher in rural counties (3.58%), compared to urban (3.10%) or metropolitan counties (2.18%) (p < .001). In terms of geographic region, the South of the United States had the highest rate of VI (2.63%) (p < .001). For age groups > 17-years-old in the 2010-2019 data, women had higher rates of VI compared to men.

CONCLUSIONS

Prevalence of self-reported visual impairment has risen and disproportionately affects certain communities. This includes individuals living in the South, in rural counties, and women.

Ocular examination findings and selected ophthalmic diagnostic tests in African green monkeys (Chlorocebus aethiops sabaeus)

OBJECTIVE

To document ocular lesions and establish ophthalmic diagnostic test reference values in a colony of African green monkeys (Chlorocebus aethiops sabaeus).

ANIMALS STUDIED

Fifty one geriatric (GAGM, 19-30 years old), 10 adult (AAGM, 5-9 years old) and 10 juvenile (JAGM, <2 years old) African green monkeys housed in a single Caribbean research colony.

PROCEDURES

Ocular biomicroscopy, indirect fundoscopy, Schirmer tear test (STT), rebound tonometry (TonoVet®) and corneal fluorescein staining were performed. Mixed ANCOVA tests were performed to compare STT and IOP between groups.

RESULTS

Common ocular lesions in GAGM included vitreal degeneration (27/51, 51/102 eyes) and cataracts (21/51, 32/102 eyes). Vitreal degeneration was also common in AAGM (8/10, 16/20 eyes) and infrequent in JAGM (3/10, 6/20 eyes). Cataracts were not present in any JAGM or AAGM. All eyes in all three groups had perilimbal corneal pigmentation and faint lace-like anterior corneal stromal opacification. Median (range) STT values were 16.0 (18) mm/min in GAGM. Mean (SD) STT values were 14.2 (4.6) mm/min in AAGM, and 8.9 (3.4) mm/min in JAGM. Median (range) IOP values were 16.5 (27) mmHg in GAGM. Mean (SD) IOP values were 18.0 (2.8) mmHg in AAGM, and 14.1 (2.2) mmHg in JAGM. JAGM had significantly lower STT and IOP values compared to AAGM (p = .0449, .0057, respectively) and GAGM (p = .0002, .0130, respectively).

CONCLUSIONS

Spontaneous ocular lesions were common in geriatric monkeys in this research colony. IOP and STT values were lower in juvenile African green monkeys relative to adult or geriatric animals.

The impact of COVID-19 on aflibercept treatment of neovascular AMD in Sweden - data from the Swedish Macula Register

BACKGROUND

The purpose of the study was to compare the real-world aflibercept treatment and visual outcomes, and to examine the adherence to pandemic guidelines in two groups of patients with treatment-naïve neovascular age-related macular degeneration (nAMD) before and during the first year of the COVID-19 pandemic in Sweden up to the 1-year follow-up.

METHODS

This is a retrospective observational study including 2915 treatment naïve eyes with nAMD. Using data from the Swedish Macula Register (SMR), 1597 eyes initiating treatment between 1 July 2018 and 31 January 2019 (pre-pandemic group) were compared with 1318 eyes starting treatment between 1 February and 31 August 2020 (pandemic group). The eyes were then followed for 1 year ± 2 months, hence the first group was unaffected by the pandemic while the second group was affected. The focus was on baseline characteristics, visual acuity (VA) change from baseline, number of injections, treatment regimen, number of appointments and the frequency and length of appointment delays. The Wilcoxon Signed-Rank Test was used to compare baseline VA to follow-up VA within the respective groups. The Mann-Whitney U-test and Fisher's exact test were used to compare outcomes between the groups.

RESULTS

Baseline characteristics were similar between the two groups. The percentage of eyes with an available follow-up VA after 1 year was 58% in the pre-pandemic group vs. 44% in the pandemic group. VA in the pre-pandemic group had increased significantly after 1 year, from 62.2 ± 14.1 letters to 64.8 ± 16.1 letters (n = 921); p < 0.0001. In the pandemic group, VA increased from 61.1 ± 15.8 to 64.9 ± 16.9 (n = 575); p < 0.0001. There was no significant difference in mean VA change between the groups; p = 0.1734. The pre-pandemic group had significantly more delays than the pandemic group, 45% vs. 36%; p < 0.0001.

CONCLUSIONS

The pre-pandemic and pandemic groups had similar VA gains at 1-year follow-up, but with a reduced number of available VA in the pandemic group. Clinics were able to implement and prioritize injection visits excluding VA measurements, helping to reduce delays and maintain VA gains during the COVID-19 pandemic.

Learning to see via epiretinal implant stimulationin silicowith model-based deep reinforcement learning

OBJECTIVE

Diseases such as age-related macular degeneration and retinitis pigmentosa cause the degradation of the photoreceptor layer. One approach to restore vision is to electrically stimulate the surviving retinal ganglion cells with a microelectrode array such as epiretinal implants. Epiretinal implants are known to generate visible anisotropic shapes elongated along the axon fascicles of neighboring retinal ganglion cells. Recent work has demonstrated that to obtain isotropic pixel-like shapes, it is possible to map axon fascicles and avoid stimulating them by inactivating electrodes or lowering stimulation current levels. Avoiding axon fascicule stimulation aims to remove brushstroke-like shapes in favor of a more reduced set of pixel-like shapes.

APPROACH

In this study, we propose the use of isotropic and anisotropic shapes to render intelligible images on the retina of a virtual patient in a reinforcement learning environment named rlretina. The environment formalizes the task as using brushstrokes in a stroke-based rendering task.

MAIN RESULTS

We train a deep reinforcement learning agent that learns to assemble isotropic and anisotropic shapes to form an image. We investigate which error-based or perception-based metrics are adequate to reward the agent. The agent is trained in a model-based data generation fashion using the psychophysically validated axon map model to render images as perceived by different virtual patients. We show that the agent can generate more intelligible images compared to the naive method in different virtual patients.

SIGNIFICANCE

This work shares a new way to address epiretinal stimulation that constitutes a first step towards improving visual acuity in artificially-restored vision using anisotropic phosphenes.

Anatomical and Functional Outcomes with Prompt versus Delayed Initiation of Anti-VEGF in Exudative Age-Related Macular Degeneration

PURPOSE

To investigate the correlation between time from diagnosis of treatment-naïve exudative age-related macular degeneration (AMD) to the introduction of anti-VEGF treatment and anatomical and functional outcomes.

DESIGN

Retrospective cohort study.

METHODS

Included were treatment-naïve exudative AMD patients who presented to a single tertiary medical center between 2012 and 2018. All patients were treated within the first 30 days of their diagnosis with three monthly intravitreal injections of bevacizumab. Patients were divided into three groups: group 1 (prompt anti-VEGF) were injected with bevacizumab within ten days, group 2 (intermediate anti-VEGF) within 11-20 days, and group 3 (delayed anti-VEGF) within 21-30 days from diagnosis. Baseline characteristics and clinical outcomes were compared up to two years from treatment.

RESULTS

146 eyes of 146 patients were included. Sixty-eight patients were in the prompt anti-VEGF group, 31 in the intermediate anti-VEGF group, and 47 in the delayed anti-VEGF group. Following the induction phase of three intravitreal bevacizumab injections, the mean central subfield macular thickness (328.0 ± 115.4 µm vs. 364.6 ± 127.2 µm vs. 337.7 ± 150.1 µm, p = 0.432) and the best-corrected visual acuity (0.47 ± 0.38 vs. 0.59 ± 0.48 vs. 0.47 ± 0.44 logMAR units, p = 0.458) were comparable between the prompt, intermediate and delayed anti-VEGF groups. Anatomical and functional outcomes, treatment burden, number of relapses and eyes with second-line anti-VEGF therapy were comparable between the groups at both 1-year and 2-year timepoints.

CONCLUSIONS

Our real-world evidence data emphasize that even if anti-VEGF induction cannot be initiated promptly within ten days from diagnosis of naïve exudative AMD, the visual and anatomical prognosis of the patients may not worsen if the treatment is started within one month of diagnosis.

Recent Advances in Imaging Macular Atrophy for Late-Stage Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. In late-stage AMD, geographic atrophy (GA) of dry AMD or choroidal neovascularization (CNV) of neovascular AMD eventually results in macular atrophy (MA), leading to significant visual loss. Despite the development of innovative therapies, there are currently no established effective treatments for MA. As a result, early detection of MA is critical in identifying later central macular involvement throughout time. Accurate and early diagnosis is achieved through a combination of clinical examination and imaging techniques. Our review of the literature depicts advances in retinal imaging to identify biomarkers of progression and risk factors for late AMD. Imaging methods like fundus photography; dye-based angiography; fundus autofluorescence (FAF); near-infrared reflectance (NIR); optical coherence tomography (OCT); and optical coherence tomography angiography (OCTA) can be used to detect and monitor the progression of retinal atrophy. These evolving diverse imaging modalities optimize detection of pathologic anatomy and measurement of visual function; they may also contribute to the understanding of underlying mechanistic pathways, particularly the underlying MA changes in late AMD.

Oxidative stress and docosahexaenoic acid injury lead to increased necroptosis and ferroptosis in retinal pigment epithelium

Age-related macular degeneration (AMD) is a complex disease caused by different genetic and environmental risk factors leading to loss of cells in the central part of the retina. Oxidative stress appears to be an important environmental risk factor that contributes to both the initiation and progression of AMD. Retinal pigment epithelium (RPE) plays an important role in regulating oxidative stress in the retina and is one of the main retinal cell types affected in AMD. A main function of RPE is to phagocytose photoreceptor outer segments (POS) which are rich in the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA), making this cell type potentially more susceptible to oxidative stress-induced lipid peroxidation which can lead to cell death. RPE is known to undergo necrotic cell death in response to oxidative stress. The aim of this study was to determine if DHA in POS can increase oxidative damage to RPE. It was found that RPE undergo increased lipid peroxidation and decreased cell viability when stressed with hydrogen peroxide in combination with DHA or POS. H2O2-induced oxidative stress was found to cause both ferroptosis and necroptosis. However, the ferroptosis regulator acyl-CoA synthetase long-chain family member 4 (ACSL4) was found to be downregulated in RPE exposed to H2O2 and this effect was exacerbated when the RPE cells were simultaneously treated with DHA. Together, these results show a response of RPE when stressed which will likely be overwhelmed under disease conditions such as AMD resulting in cell death.

Visual impairment and blindness caused by retinal diseases: A nationwide register-based study

Background

Retinal disorders cause substantial visual burden globally. Accurate estimates of the vision loss due to retinal diseases are pivotal to inform optimal eye health care planning and allocation of medical resources. The purpose of this study is to describe the proportion of visual impairment and blindness caused by major retinal diseases in China.

Methods

A nationwide register-based study of vitreoretinal disease covering all 31 provinces (51 treating centres) of mainland China. A total of 28 320 adults diagnosed with retinal diseases were included. Participants underwent standardised ocular examinations, which included best-corrected visual acuity (BCVA), dilated-fundus assessments, and optical coherence tomography. Visual impairment and blindness are defined using BCVA according to the World Health Organization (WHO) (visual impairment: <20/63-≥20/400; blindness: <20/400) and the United States (visual impairment: <20/40-≥20/200; blindness: <20/200) definitions. The risk factors of vision loss were explored by logistic regression analyses.

Results

Based on the WHO definitions, the proportions for unilateral visual impairment and blindness were 46% and 18%, respectively, whereas those for bilateral visual impairment and blindness were 31% and 3.3%, respectively. Diabetic retinopathy (DR) accounts for the largest proportion of patients with visual impairment (unilateral visual impairment: 32%, bilateral visual impairment: 60%) and blindness (unilateral blindness: 35%; bilateral blindness: 64%). Other retinal diseases that contributed significantly to vision loss included age-related macular degeneration, myopic maculopathy, retinal vein occlusion, and rhegmatogenous retinal detachment and other macular diseases. Women (bilateral vision loss: P = 0.011), aged patients (unilateral vision loss: 45-64 years: P < 0.001, ≥65 years: P < 0.001; bilateral vision loss: 45-64 years: P = 0.003, ≥65 years: P < 0.001 (reference: 18-44 years)) and those from Midwest China (unilateral and bilateral vision loss: both P < 0.001) were more likely to suffer from vision loss.

Conclusions

Retinal disorders cause substantial visual burden among patients with retinal diseases in China. DR, the predominant retinal disease, is accountable for the most prevalent visual disabilities. Better control of diabetes and scaled-up screenings are warranted to prevent DR. Specific attention should be paid to women, aged patients, and less developed regions.

Polymorphic nanobody crystals as long-acting intravitreal therapy for wet age-related macular degeneration

Wet age-related macular degeneration (wet AMD) is the most common cause of blindness, and chronic intravitreal injection of anti-vascular endothelial growth factor (VEGF) proteins has been the dominant therapeutic approach. Less intravitreal injection and a prolonged inter-injection interval are the main drivers behind new wet AMD drug innovations. By rationally engineering the surface residues of a model anti-VEGF nanobody, we obtained a series of anti-VEGF nanobodies with identical protein structures and VEGF binding affinities, while drastically different crystallization propensities and crystal lattice structures. Among these nanobody crystals, the P212121 lattice appeared to be denser and released protein slower than the P1 lattice, while nanobody crystals embedding zinc coordination further slowed the protein release rate. The polymorphic protein crystals could be a potentially breakthrough strategy for chronic intravitreal administration of anti-VEGF proteins.

Nationwide and regional trends in distance and near visual acuities during 2000-2017 in Finland

PURPOSE

To evaluate time trends in distance and near vision at the national and regional levels during 2000-2017 in Finland.

METHODS

We used three cross-sectional, nationwide health examination surveys representing the Finnish adult population aged 30 years or older in 2000, 2011 and 2017. Bilateral, habitual distance and near visual acuity (VA) were measured in all three surveys.

RESULTS

The prevalence of good distance vision (VA ≥ 1.0) increased from 76.7% to 81.3% during 2000-2017 while the prevalence of weak or worse distance vision (VA ≤ 0.5) decreased from 7.6% to 3.7%. The improvements were largest among those aged 85 years and older: the prevalence of distance VA ≤ 0.5 decreased from 71.8% to 28.3%. Near vision showed improvement to a lesser extent in the total population; nevertheless, among those aged 85 years and older the prevalence of weak or worse near vision (VA ≤ 0.5) decreased from 62.3% to 27.1%. A similar positive time trend was observed in all main regions of Finland, and differences between urban and rural regions were small.

CONCLUSION

During the past two decades, the overall vision level has improved among the adult population. This is explained mostly by a positive shift from lower to higher vision levels among older age groups, indicating that people live longer with good or adequate vision. This positive trend showed remarkable similarity throughout different regions in Finland, highlighting the importance of equal and accessible eye care throughout the country.

The underestimated role of myopia in uncorrectable visual impairment in the United States

We estimate the US prevalence of uncorrectable visual impairment in 2050 accounting for the changing distribution of both age and myopia. Age projections of the US population (from an estimated total of 379 million in 2050), were taken from the US census website. The distribution of myopia, by severity, was calculated from literature-derived prevalence estimates of 58.4% (≤ - 0.50 D, 2050 projection) and 33.1% (≤ - 1.00 D, 1999-2004 estimate) to provide predicted and conservative estimates, respectively. Uncorrectable visual impairment as a function of age and refractive error was modelled by multiple linear regression. Finally, the likely number of individuals in the US with visual impairment in 2050 was calculated. For a projected myopia prevalence of 58.4%, 222 million are projected to be myopic and 48 million will have high myopia (- 5 D or worse). The projected total number with uncorrectable visual impairment is 11.4 million of which 4.9 million cases (43%) of visual impairment will be directly attributed to increased risk of eye disease associated with myopia. For a projected myopia prevalence of 33.1%, 8.9 million are projected to have uncorrectable visual impairment of which 2.4 million cases (27%) will be directly attributed to myopia. It is predicted that between 27 and 43% of uncorrectable visual impairment in the US population in 2050 will be directly attributable to myopia. Failure to account for the increasing prevalence of myopia among the aging population leads to a substantial underestimate of the prevalence of visual impairment.

Porcine models of choroidal neovascularization: A systematic review

Animal models of choroidal neovascularization (CNV) are extensively used in translational studies of CNV formation and to evaluate angiostatic treatment strategies. However, the current paucity of large animal models compared with rodent models constitutes a knowledge gap regarding the clinical translation of findings. Ocular anatomical and physiological similarities to humans suggest the pig as a relevant model animal. Thus, a systematic survey of porcine CNV models was performed to identify pertinent model parameters and suggest avenues for model standardization and optimization. A systematic search was performed in PubMed and EMBASE on November 28, 2022 for porcine models of CNV. Following inclusion by two investigators, data from the articles were extracted according to a predefined protocol. A total of 14 articles, representing 19 independent porcine CNV models were included. The included models were almost equally divided between laser-induced (53%) and surgically-induced (47%) models. Different specified breeds of domestic pigs (71%) were most commonly used in the studies. All studies used normal animals. Female pigs were reported used in 43% of the studies, while 43% did not report on sex of the animals. Younger pigs were typically used. The surgical models reported consistent CNV induction following mechanical Bruch's membrane rupture. The laser models used variants of the infrared diode laser (40%) or the frequency-doubled Nd:YAG laser (50%). Both lasers enabled successful CNV induction with reported induction rates ranging from 60 to 100%. Collateral damage to the neuroretina was reported for the infrared diode laser. CNV evaluation varied across studies with fluorescein angiography (50%) as the most used in vivo method and retinal sections (71%) as the most used ex vivo method. In interventional studies, quantification of lesions was in general performed between 7 and 14 days. The field of porcine CNV models is relatively small and heterogeneous and almost equally divided between surgically-induced and laser-induced models. Both methods have allowed successful modeling of CNV formation with induction rates comparable to those of non-human primates. However, the field would benefit from standardization of model parameters and reporting. This includes laser parameters and validation of CNV formation as well as methods of CNV evaluation and statistical analysis.

Cataract surgery in neovascular AMD: impact on visual acuity and disease activity

BACKGROUND

Cataract and neovascular age-related macular degeneration (nAMD) often co-exist and both contribute to impaired vision. It has been debated whether cataract surgery can increase nAMD activity. The purpose of this retrospective study was to investigate the impact of cataract surgery on visual acuity, treatment intensity for nAMD and macular morphology in patients with on-going treatment for nAMD.

METHODS

Data was obtained from the Swedish Macular Register, the Swedish National Cataract Register, optical coherence tomography (OCT) images and patient charts. All eyes were treated at the Department of Ophthalmology at the County Hospital of Västmanland, Västerås, Sweden. Follow-up was 6 months after surgery. The study was approved by the Swedish Ethical Review Authority.

RESULTS

In total, 156 patients (168 eyes) were included. The mean age at cataract surgery was 82 (standard deviation, SD 6) years. Both distance and near visual acuity improved after surgery. Distance visual acuity increased from 59 (SD 12) to 66 (SD 15) letters ETDRS (P < 0.001). Proportion of eyes with normal near visual acuity increased from 12 to 41%. The anti-vascular endothelial growth factor (VEGF) treatment intensity remained unchanged: mean of 3.4 (SD 1.9) and 3.3 (SD 1.7) treatments were given 6 months pre- and postoperatively, respectively. The prevalence of intraretinal fluid (IRF) in the macula increased from 22 to 31% postoperatively, while subretinal fluid, fluid under the pigment epithelium (sub-RPE fluid) and central retinal thickness were unaltered. In eyes with new IRF, improvement in visual acuity and number of anti-VEGF treatments were similar to eyes without new IRF.

CONCLUSION

Cataract surgery improved visual acuity in patients with on-going treatment for nAMD and did not affect anti-VEGF treatment intensity. Macular morphology remained unchanged. The slight increase in intraretinal fluid after surgery was not found to affect visual acuity or anti-VEGF treatment intensity. It is hypothesized that this might indicate that it represents degenerative intraretinal cystic fluid.

Myopia Control Dose Delivered to Treated Eyes by a Dual-focus Myopia-control Contact Lens

PURPOSE

This study examined the optical impact of a DF contact lens during near viewing in a sample of habitual DF lens wearing children.

METHODS

Seventeen myopic children aged 14 to 18 years who had completed 3 or 6 years of treatment with a DF contact lens (MiSight 1 Day; CooperVision, Inc., San Ramon, CA) were recruited and fit bilaterally with the DF and a single-vision (Proclear 1 Day; CooperVision, Inc.) contact lens. Right eye wavefronts were measured using a pyramidal aberrometer (Osiris; CSO, Florence, Italy) while children accommodated binocularly to high-contrast letter stimuli at five target vergences. Wavefront error data were used to compute pupil maps of refractive state.

RESULTS

During near viewing, children wearing single-vision lenses accommodated on average to achieve approximate focus in the pupil center but, because of combined accommodative lag and negative spherical aberration, experienced up to 2.00 D of hyperopic defocus in the pupil margins. With DF lenses, children accommodated similarly achieving approximate focus in the pupil center. When viewing three near distances (0.48, 0.31, and 0.23 m), the added +2.00 D within the DF lens treatment optics shifted the mean defocus from +0.75 to -1.00 D. The DF lens reduced the percentage of hyperopic defocus (≥+0.75 D) in the retinal image from 52 to 25% over these target distances, leading to an increase in myopic defocus (≤-0.50 D) from 17 to 42%.

CONCLUSIONS

The DF contact lens did not alter the accommodative behavior of children. The treatment optics introduced myopic defocus and decreased the amount of hyperopically defocused light in the retinal image.

Targeted RNAi screen identifies transcriptional mechanisms that prevent premature degeneration of adult photoreceptors

Aging is associated with a decline in visual function and increased prevalence of ocular disease, correlating with changes in the transcriptome and epigenome of cells in the eye. Here, we sought to identify the transcriptional mechanisms that are necessary to maintain photoreceptor viability and function during aging. To do this, we performed a targeted photoreceptor-specific RNAi screen in Drosophila to identify transcriptional regulators whose knockdown results in premature, age-dependent retinal degeneration. From an initial set of 155 RNAi lines each targeting a unique gene and spanning a diverse set of transcription factors, chromatin remodelers, and histone modifiers, we identified 18 high-confidence target genes whose decreased expression in adult photoreceptors leads to premature and progressive retinal degeneration. These 18 target genes were enriched for factors involved in the regulation of transcription initiation, pausing, and elongation, suggesting that these processes are essential for maintaining the health of aging photoreceptors. To identify the genes regulated by these factors, we profiled the photoreceptor transcriptome in a subset of lines. Strikingly, two of the 18 target genes, Spt5 and domino, show similar changes in gene expression to those observed in photoreceptors with advanced age. Together, our data suggest that dysregulation of factors involved in transcription initiation and elongation plays a key role in shaping the transcriptome of aging photoreceptors. Further, our findings indicate that the age-dependent changes in gene expression not only correlate but might also contribute to an increased risk of retinal degeneration.

Visual impairment due to age-related macular degeneration during 40 years in Finland and the impact of novel therapies

PURPOSE

To evaluate the changes in visual impairment (VI) due to age-related macular degeneration (AMD) during the past 40 years and the impact of novel therapies at population level.

METHODS

In this nationwide register-based study, we assessed the incidence, prevalence, severity, and onset age of VI due to AMD based on the Finnish Register of Visual Impairment data from 1980 to 2019. Our data included 30 016 visually impaired persons with AMD as the main diagnosis for VI. The number of persons treated with intravitreal injections in Finland was obtained from hospital data kept by the Finnish Institute for Health and Welfare.

RESULTS

Between the 1980s and the 2010s, the incidence of reported VI doubled; however, this increase has stagnated in the 2010s. Since 2012, the prevalence of reported VI has decreased. The number of patients treated with intravitreal injections showed a 40-fold increase during 2005-2019. The severity of reported VI has decreased whereas the mean age at the onset of reported VI has increased during the 40 years. The age-adjusted incidence and prevalence of reported VI were significantly higher in females in comparison to males in all decades.

CONCLUSION

Increase in the incidence and prevalence of VI due to AMD in the past decades has stagnated and shifted to older age in the 2010s when therapies for exudative class became commonly available. Furthermore, the prognosis of VI has improved during the past 40 years. These positive trends are likely contributable to improved diagnostic tools, earlier diagnoses, and new therapy options.

Progression of Myopic Maculopathy: A Systematic Review and Meta-Analysis

PURPOSE

The purpose of this study was to elucidate the risk factors for the progression of myopic maculopathy (MM) based on severity.

METHODS

In this study, we conducted a systematic review and meta-analysis of the literature published before December 2020 on the risk factors for the progression of MM in patients with pathologic myopia (PM) and high myopia (HM). Odds ratios (ORs) for different stages of myopic maculopathy categorized based on the International Meta-Analysis for PM (META-PM) classification were calculated using fixed and random effects models.

RESULTS

A total of 12,070 affected eyes derived from 5 cohort studies were included in the systematic review. The presence of PM at baseline was found to be significantly associated with an increased risk of MM progression (pooled ORs: 7.17, 95% confidence interval [CI]: 3.29-15.6), and the greater category of MM at baseline was found to be significantly associated with an increased risk of MM progression, that is, eyes with MM category 3 or more compared with eyes with MM category 2 (pooled OR: 10.95, 95% CI: 6.07-19.76) and eyes with MM category 4 compared with eyes with MM category 3 (pooled ORs: 2.45, 95% CI: 0.28-21.37).

CONCLUSIONS

The findings in this systematic review and meta-analysis indicate that the progression of MM is associated with more severe MM at baseline.

Nano-Formulation of Antioxidants as Effective Inhibitors of γD-Crystallin Aggregation

The aggregation of crystallin proteins is related to cataracts and age-related macular degeneration. Apart from surgical replacement of the cataract lens, no other alternative treatment is available till date for this ailment. In the current work, we carried out an in-depth investigation of the effect of polyphenol-loaded nano-formulations on the aggregation of γD-crystallin. At first, the protein was allowed to form amorphous aggregates under denaturing conditions. Several polyphenols were then tried to inhibit the aggregation of the protein. Among the polyphenols tested, resveratrol and quercetin were found to be the most effective. Since polyphenols are prone to degradation, they were encapsulated in chitosan nanoparticles in order to provide ambient conditions for them to function effectively. The loading efficiency and polyphenol release kinetics were subsequently tested. Finally, the efficacy of resveratrol/quercetin-loaded chitosan nano-particles as inhibitors of γD-crystallin aggregation was confirmed in a series of experiments demonstrating the potency of the system in the prospective therapeutic intervention of eye ailments concerning self-assembly of γD-crystallin proteins.

Electrophysiological Evaluation of Macular Photoreceptor Functions in Patients with Choroidal Neovascular Membranes

PURPOSE

To evaluate changes in cone functions using light-adapted (LA) 30 Hz flicker and LA 3.0 electroretinography (ERG) in intravitreal ranibizumab (IVR)-treated naïve neovascular age-related macular degeneration (nAMD) patients.

MATERIALS AND METHODS

This retrospective interventional study reviewed the medical records of 32 nAMD patients (32 eyes) who received monthly IVR between January 2019 and January 2021. A comprehensive ophthalmic examination, including best-corrected visual acuity (BCVA) testing and slit-lamp biomicroscopy, was performed as part of their clinical care, followed by LA 30 Hz flicker and LA 3.0 ERGs, optical coherence tomography, and fundus fluorescein angiography. All measurements were taken before IVR (baseline), as well as at months 6 and 12 later. Treatment was resumed for up to 12 months if recurrence occurred.

RESULTS

Compared to baseline, visual acuity improved significantly at months 6 and 12, respectively, coinciding with a significant decrease in central macular thickness (p < 0.05 for all). LA 30 Hz flicker ERG b-wave amplitude decreased significantly between baseline and months 6 and 12, respectively (p < 0.05 for both). There were no significant changes in LA 3.0 ERG a- and b-wave amplitudes between baseline and month 6 (p > 0.05 for both), but a significant decrease existed between baseline and month 12 (p < 0.05 for both). While LA 3.0 ERG a-wave implicit time increased significantly (p < 0.05 for both) between baseline and months 6 and 12, respectively, b-wave implicit time did not (p > 0.05 for both). Also, LA 30 Hz flicker ERG b-wave implicit times did not differ significantly between baseline and months 6 and 12, respectively (p > 0.05, for both).

CONCLUSIONS

IVR was associated with long-term electrophysiological changes in cone functions, as measured by LA 30 Hz flicker and LA 3.0 ERGs.

Five-year follow-up of corneal endothelial cell density after transscleral ab interno glaucoma gel stent implantation

Purpose

This study investigates the course of the endothelial cell density over a period of 5 years after XEN45 implantation (XEN45µm, Allergan Plc., USA) with or without combined cataract surgery.

Methods

This is a prospective, cross-sectional, monocentric, non-randomized clinical trial with the intention to treat a population of the University Eye Clinic Glaucoma Service Salzburg. One hundred and fifty-five eyes with preoperative central corneal endothelial cell counts were subjected to XEN45 implantation with (combined surgery group) or without (solo surgery group) combined cataract surgery. Endothelial cell density was measured at 3 corneal positions. XEN45 location parameters were determined with anterior segment OCT and gonioscopy.

Results

In the combined surgery group, a significant reduction of central endothelial cell count was found at years 2 and 4 when compared to baseline (p = 0.001 and p = 0.02, n = 86), whereas at years 1, 3, and 5, no change was detected (all p > 0.09). The median reduction of endothelial cell count was − 79 (95% CI: − 183 to − 9) and − 93 (95% CI: − 220 to 23) cells at years 2 and 4, respectively. In the solo surgery group (n = 69), no significant change in endothelial cell counts was detected at any time during the 5-year evaluation period (all p > 0.07). Explorative data analyses revealed that XEN45 location parameters did not significantly influence the course of endothelial cell count over time.

Conclusions

Endothelial cell loss after XEN45 implantation seems to be low. The present data suggest no impact on the position of the implant with regard to central endothelial cell counts in this study.

Validation of an autonomous artificial intelligence-based diagnostic system for holistic maculopathy screening in a routine occupational health checkup context

PURPOSE

This study aims to evaluate the ability of an autonomous artificial intelligence (AI) system for detection of the most common central retinal pathologies in fundus photography.

METHODS

Retrospective diagnostic test evaluation on a raw dataset of 5918 images (2839 individuals) evaluated with non-mydriatic cameras during routine occupational health checkups. Three camera models were employed: Optomed Aurora (field of view - FOV 50º, 88% of the dataset), ZEISS VISUSCOUT 100 (FOV 40º, 9%), and Optomed SmartScope M5 (FOV 40º, 3%). Image acquisition took 2 min per patient. Ground truth for each image of the dataset was determined by 2 masked retina specialists, and disagreements were resolved by a 3rd retina specialist. The specific pathologies considered for evaluation were "diabetic retinopathy" (DR), "Age-related macular degeneration" (AMD), "glaucomatous optic neuropathy" (GON), and "Nevus." Images with maculopathy signs that did not match the described taxonomy were classified as "Other."

RESULTS

The combination of algorithms to detect any abnormalities had an area under the curve (AUC) of 0.963 with a sensitivity of 92.9% and a specificity of 86.8%. The algorithms individually obtained are as follows: AMD AUC 0.980 (sensitivity 93.8%; specificity 95.7%), DR AUC 0.950 (sensitivity 81.1%; specificity 94.8%), GON AUC 0.889 (sensitivity 53.6% specificity 95.7%), Nevus AUC 0.931 (sensitivity 86.7%; specificity 90.7%).

CONCLUSION

Our holistic AI approach reaches high diagnostic accuracy at simultaneous detection of DR, AMD, and Nevus. The integration of pathology-specific algorithms permits higher sensitivities with minimal impact on its specificity. It also reduces the risk of missing incidental findings. Deep learning may facilitate wider screenings of eye diseases.

Automatic Segmentation and Measurement of Choroid Layer in High Myopia for OCT Imaging Using Deep Learning

Automatic segmentation and measurement of the choroid layer is useful in studying of related fundus diseases, such as diabetic retinopathy and high myopia. However, most algorithms are not helpful for choroid layer segmentation due to its blurred boundaries and complex gradients. Therefore, this paper aimed to propose a novel choroid segmentation method that combines image enhancement and attention-based dense (AD) U-Net network. The choroidal images obtained from optical coherence tomography (OCT) are pre-enhanced by algorithms that include flattening, filtering, and exponential and linear enhancement to reduce choroid-independent information. Experimental results obtained from 800 OCT B-scans of the choroid layers from both normal eyes and high myopia showed that image enhancement significantly increased the performance of ADU-Net, with an AUC of 99.51% and a DSC of 97.91%. The accuracy of segmentation using the ADU-Net method with image enhancement is superior to that of the existing networks. In addition, we describe some algorithms that can measure automatically choroidal foveal thickness and the volume of adjacent areas. Statistical analyses of the choroidal parameters variation indicated that compared with normal eyes, high myopia has a reduction of 86.3% of the choroidal foveal thickness and 90% of the adjacent volume. It proved that high myopia is likely to cause choroid layer attenuation. These algorithms would have wide application in the diagnosis and precaution of related fundus lesions caused by choroid thinning from high myopia in future studies.

Animal Models of Choroidal Neovascularization: A Systematic Review

Purpose

Animal models of choroidal neovascularization (CNV) are extensively used to characterize the pathophysiology of chorioretinal diseases with CNV formation and to evaluate novel treatment strategies. This systematic review aims to give a detailed overview of contemporary animal models of CNV.

Methods

A systematic search was performed in PubMed and EMBASE from November 20, 2015, to November 20, 2020, for mammalian animal models of CNV. Following inclusion by two investigators, data from the articles were extracted according to a predefined protocol.

Results

A total of 380 full articles, representing 409 independent animal models, were included. Mice were by far the most utilized animal (76%) followed by rats and non-human primates. The median age of rodents was 8 weeks but with a wide range. Male animals were used in 44% of the studies, but 32% did not report the sex. CNV was laser induced in 89% of the studies, but only 44% of these reported sufficiently on standard laser parameters. Surprisingly, 28% of the studies did not report a sample size for quantitative CNV evaluation. Less than half of the studies performed quantitative in vivo evaluation, and 73% evaluated CNV quantitatively ex vivo. Both in vivo and ex vivo evaluations were conducted primarily at day 7 and/or day 14.

Conclusions

The laser-induced mouse model is the predominant model for experimental CNV. The widespread use of young, healthy male animals may complicate clinical translation, and inadequate reporting challenges reproducibility. Definition and implementation of standardized methodologic and reporting guidelines are attractive.

Uncharted territory: The feasibility of serial computerised cognitive assessment the first week post-stroke

BACKGROUND

Cognitive impairment is common and problematic post-stroke, yet vital information to understand early cognitive recovery is lacking. To examine early cognitive recovery, it is first necessary to establish the feasibility of repeat cognitive assessment during the acute post-stroke phase.

OBJECTIVE

To determine if serial computerised testing is feasible for cognitive assessment in an acute post-stroke phase, measured by assessment completion rates.

METHOD

An observational cohort study recruited consecutive stroke patients admitted to an acute stroke unit within 48 hours of onset. Daily assessment with the Cambridge Neuropsychological Test Automated Battery (CANTAB) was performed for seven days, and single Montreal Cognitive Assessment (MoCA).

RESULTS

Seventy-one participants were recruited, mean age 74 years, with 67 completing daily testing. Participants had predominantly mild (85%; NIHSS ≤6), ischemic (90%) stroke, 32% demonstrated clinical delirium. The first day of testing, 76% of participants completed CANTAB batteries. Eighty-seven percent of participants completed MoCA a mean of 3.4 days post-stroke. The proportion of CANTAB batteries completed improved significantly from day 2 to day 3 post-stroke with test completion rates stabilizing ≥ 92% by day 4. Participants with incomplete CANTAB were older, with persisting delirium, and longer stay in acute care.

CONCLUSION

Serial computerised cognitive assessments are feasible the first week post-stroke and provide a novel approach to measuring cognitive change for both clinical and research purposes. Maximum completion rates by day four have clinical implications for optimal timing of cognitive testing.

The Impact of Cost-Containment Schemes on Outpatient Services for Schoolchildren with Refractive Errors in Taiwan—A Population-Based Study

Objectives: Extant research on cost-sharing finds no impact on health care utilization when the amount is insubstantial. This research investigates the effects on nonacute outpatient services for schoolchildren with refractive errors in Taiwan and discusses the potential harm caused by cost sharing and relevant cost containment policies. Methods: Longitudinal claims data from the National Health Insurance database are employed. District demographic information is also used for aggregate-level analyses. Interventional modeling is conducted on pooled individual-level data with a Poisson model and negative binomial models. Generalized least square modeling is performed on aggregate district-level data to elucidate the impacts of cost sharing and the reimbursement rate with controls for patient and institutional characteristics, district socioeconomic factors, and competitiveness among institutions. Results: The findings of this study show that cost sharing does not significantly affect children’s utilization of outpatient services in the patient-level analyses. However, it significantly decreases the service volume based on the results of district aggregate analyses. There are potentially marginal patients in society, and they are more likely to be girls in poorer families, whose chances of seeking medical care significantly decrease when cost sharing increases. Conclusions: The gap in health inequity can be widened when stringent cost-containment policies are implemented. The offset effect caused by delayed care may also result in higher health care expenditures later. Cost sharing for children should be separately and prudently designed to better protect them from deprivations caused by changes in health policies.

Prevalence and Causes of Visual Impairment and Blindness in Elderly Population; an Urgent Geriatric Health Issue: Tehran Geriatric Eye Study (TGES)

PURPOSE

To determine the prevalence of vision impairment (VI) and blindness and their determinants in the elderly population of Tehran.

METHODS

In a cross-sectional study, multi-stage cluster sampling was used to select a sample of over 60 year population of Tehran. Optometric examinations included the measurement of uncorrected visual acuity, objective and subjective refraction, presenting and best corrected visual acuity. Vision impairment is reported according to the WHO definition. Visual acuity worse than 20/60 and 20/400 in the better eye was regarded as low vision and blindness, respectively.

RESULTS

According to presenting visual acuity, VI was found in 14.8% (95%CI: 13.1-16.5) of the participants, including low vision in 13.8% (95%CI: 12.2-15.4) and blindness in 1.1% (95%CI: 0.5-1.6). The prevalence of VI ranged between 7.8% (95%CI: 6.0-9.5) in subjects aged 60-64 years and 40.0% (95%CI: 33.0-47.0) in participants over 80 years (p < .001). Multivariable logistic regression analysis showed that older age (OR = 1.07(per year)), lower education level (illiterate versus college: OR = 3.55), and lower economic status (middle versus rich: OR = 1.30 and poor versus rich; OR = 1.72) had a significant relationship with an increase in the prevalence of VI, and older age (OR = 1.14(Per year increase)) and diabetes (OR = 2.62) had a significant relationship with blindness. Refractive errors (63.1%) was the leading cause of VI followed by cataract (22.5%). However, cataract (48.3%) was the leading cause of blindness.

CONCLUSION

Many older adults suffer from VI. Correction of refractive errors and cataract reduces a large percentage of VI. Age, education level, and economic status are other determinants of VI.

Influence of Race, Ethnicity, and Socioeconomic Factors in Idiopathic Macular Hole Presentation and Surgical Outcomes

BACKGROUND AND OBJECTIVE

To characterize the influence of race, ethnicity, and socioeconomic factors on idiopathic macular hole (IMH) presentation and surgical outcomes.

PATIENTS AND METHODS

This retrospective cohort study of patients diagnosed with IMH who underwent surgical repair collected IMH data from optical coherence tomography scans as well as demographic information. Univariate and multivariate regression models interrogated relevant relationships.

RESULTS

Of 292 eyes analyzed, 223 (76.4%) patients were White and 53 (18.2%) were Black. Mean income was $57,076.9 ± 17,794.7. Black patients presented with 0.05 mm² larger IMH area (95% CI, 0.01 to 0.09; P = .01) and 69.07 µm wider minimum linear diameter (95% CI, 15.05 to 123.10; P = .01). Patients with higher income presented with 3.76 µm narrower base diameter (95% CI, -6.42 to -1.09; P = .006).

CONCLUSIONS

Black patients were associated with larger IMH at presentation, and higher income patients were associated with smaller IMH. [Ophthalmic Surg Lasers Imaging Retina 2022;53(6): 333-344.].

Dry Eye and Meibomian Gland Dysfunction in Neovascular Age-Related Macular Degeneration Patients Treated with Intravitreal Injections

Objectives:

To determine if patients treated with multiple intravitreal injections for neovascular age-related macular degeneration are more likely to suffer from dry eye and meibomian gland dysfunction.

Materials and Methods:

Sixty eyes of 30 patients were enrolled. One eye of each patient was treated with multiple monthly intravitreal injections for neovascular AMD (Group 1) and the fellow healthy eye received no treatment (Group 2). The presence of dry eye was evaluated using tear film break-up time, Schirmer 1 test, the Oxford scale, and Ocular Surface Disease Index (OSDI). The loss rate of meibomian glands was evaluated by meibography and was graded and scored (meiboscore) from grade 0 (no loss of glands) to grade 3 (loss of >2/3 of total meibomian glands) for each eyelid.

Results:

Group 1 had lower mean Schirmer 1 and tear film break up-time measurements and higher mean OSDI score than Group 2, but the differences were not statistically significant (p=0.257, p=0.113, and p=0.212, respectively). Mean Oxford scale scores and meiboscore of the upper eyelids showed no statistically significant difference between the groups (p=0.594, p=0.663, respectively). The meiboscore of the lower eyelids was significantly higher in Group 1 (p=0.048).

Conclusion:

Multiple factors such as povidone-iodine and the preservatives in topical eye drops may cause inflammation leading to ocular surface damage in patients treated with multiple intravitreal injections. As the treatment requires repeated injections, exposure to these factors might worsen the ocular surface inflammation. The possibility of dry eye and meibomian gland dysfunction should be considered in these patients.

Novel Uses and Challenges of Artificial Intelligence in Diagnosing and Managing Eyes with High Myopia and Pathologic Myopia

Myopia is a global health issue, and the prevalence of high myopia has increased significantly in the past five to six decades. The high incidence of myopia and its vision-threatening course emphasize the need for automated methods to screen for high myopia and its serious form, named pathologic myopia (PM). Artificial intelligence (AI)-based applications have been extensively applied in medicine, and these applications have focused on analyzing ophthalmic images to diagnose the disease and to determine prognosis from these images. However, unlike diseases that mainly show pathologic changes in the fundus, high myopia and PM generate even more data because both the ophthalmic information and morphological changes in the retina and choroid need to be analyzed. In this review, we present how AI techniques have been used to diagnose and manage high myopia, PM, and other ocular diseases and discuss the current capacity of AI in assisting in preventing high myopia.

Clinical explainable differential diagnosis of polypoidal choroidal vasculopathy and age-related macular degeneration using deep learning

BACKGROUND

This study aims to achieve an automatic differential diagnosis between two types of retinal pathologies with similar pathological features - Polypoidal choroidal vasculopathy (PCV) and wet age-related macular degeneration (AMD) from volumetric optical coherence tomography (OCT) images, and identify clinically-relevant pathological features, using an explainable deep-learning-based framework.

METHODS

This is a retrospective study with data from a cross-sectional cohort. The OCT volume of 73 eyes from 59 patients was included in this study. Disease differentiation was achieved through single-B-scan-based classification followed by a volumetric probability prediction aggregation step. We compared different labeling strategies with and without identifying pathological B-scans within each OCT volume. Clinical interpretability was achieved through normalized aggregation of B-scan-based saliency maps followed by maximum-intensity-projection onto the en face plane. We derived the PCV score from the proposed differential diagnosis framework with different labeling strategies. The en face projection of saliency map was validated with the pathologies identified in Indocyanine green angiography (ICGA).

RESULTS

Model trained with both labeling strategies achieved similar level differentiation power (>90%), with good correspondence between pathological features detected from the projected en face saliency map and ICGA.

CONCLUSIONS

This study demonstrated the potential clinical application of non-invasive differential diagnosis using AI-driven OCT-based analysis, with minimal requirement of labeling efforts, along with clinical explainability achieved through automatically detected disease-related pathologies.

Long-term Effect of Dual-focus Contact Lenses on Myopia Progression in Children: A 6-year Multicenter Clinical Trial

SIGNIFICANCE

Treatment of myopic children with a dual-focus soft contact lens (DFCL; MiSight 1 day) produced sustained slowing of myopia progression over a 6-year period. Significant slowing was also observed in children switched from a single vision control to treatment lenses (3 years in each lens).

PURPOSE

This study aimed to evaluate the effectiveness of DFCLs in sustaining slowed progression of juvenile-onset myopia over a 6-year treatment period and assess myopia progression in children who were switched to a DFCL at the end of year 3.

METHODS

Part 1 was a 3-year clinical trial comparing DFCLs with a control contact lens (Proclear 1 day) at four investigational sites. In part 2, subjects completing part 1 were invited to continue for 3 additional years during which all children were treated with MiSight 1 day DFCLs (52 and 56 from the initially treated [T6] and control [T3] groups, respectively). Eighty-five subjects (45 [T3] and 40 [T6]) completed part 2. Cyclopleged spherical equivalent refractive errors (SEREs) and axial lengths (ALs) were monitored, and a linear mixed model was used to compare their adjusted change annually.

RESULTS

Average ages at part 2 baseline were 13.2 ± 1.3 and 13.0 ± 1.5 years for the T6 and T3 groups, respectively. Slowed myopia progression in the T6 group observed during part 1 was sustained throughout part 2 (mean ± standard error of the mean: change from baseline SERE [in diopters], -0.52 ± 0.076 vs. -0.51 ± 0.076; change in AL [in millimeters], 0.28 ± 0.033 vs. 0.23 ± 0.033; both P > .05). Comparing progression rates in part 2 for the T6 and T3 groups, respectively, indicates that prior treatment does not influence efficacy (SERE, -0.51 ± 0.076 vs. -0.34 ± 0.077; AL, 0.23 ± 0.03 vs. 0.18 ± 0.03; both P > .05). Within-eye comparisons of AL growth revealed a 71% slowing for the T3 group (3 years older than part 1) and further revealed a small subset of eyes (10%) that did not respond to treatment.

CONCLUSIONS

Dual-focus soft contact lenses continue to slow the progression of myopia in children over a 6-year period revealing an accumulation of treatment effect. Eye growth of the initial control cohort with DFCL was slowed by 71% over the subsequent 3-year treatment period.

Underdiagnosis of glaucoma in patients with exudative age-related macular degeneration

OBJECTIVE

To compare the rate of glaucoma-related diagnoses in patients with exudative or non-exudative age-related macular degeneration (AMD).

METHODS

Patients above the age of 55 with a diagnosis of AMD were identified from billing records from 2015 to 2018. Out of the 3991 patients with AMD, two cohorts with 990 patients in each were formed by randomly age-matching patients with exudative AMD with those with non-exudative AMD; patients within each group were further classified by subtype and severity of glaucoma. Charts of AMD patients without glaucoma-related diagnoses were reviewed to determine potential underdiagnosis. We applied a set of broad clinical criteria that comprised an intraocular pressure ≥22 mmHg, a cup-to-disc ratio (CDR) ≥ 0.6, and/or CDR difference between eyes of ≥0.2.

RESULTS

The rate of diagnosed, open-angle glaucoma was significantly lower in patients with exudative AMD (6.06%) compared to patients with non-exudative AMD (8.99%, P = 0.04). Similarly, the rate of suspected glaucoma was significantly lower in the first group compared to the second (12.12% versus 18.48%, respectively, P < 0.001). A greater number of patients with exudative AMD (13.94%, n = 138) met clinical risk criteria compared with those having non-exudative AMD (6.97%, n = 69, P < 0.001). When these at-risk patients were added to their respective groups, the rate of glaucoma, or its suspicion, became similar (χ2 = 1.24, P = 0.539).

CONCLUSIONS

A significantly lower rate of diagnosed glaucoma, or its suspicion, was identified in patients with exudative compared to non-exudative AMD. This apparent underdiagnosis was resolved by the retrospective application of clinical criteria that may represent a risk of glaucoma.

Dietary Antioxidants in Age-Related Macular Degeneration and Glaucoma

Age-related macular degeneration (AMD) and glaucoma are ophthalmic neurodegenerative diseases responsible for irreversible vision loss in the world population. Only a few therapies can be used to slow down the progression of these diseases and there are no available treatment strategies for reversing the degeneration of the neural retina. In AMD, the pathological process causes the malfunction and damage of the retinal pigmented epithelium and photoreceptors in the macula. In glaucoma, damage of the retinal ganglion cells and their axons is observed and treatment strategies are limited to intraocular pressure lowering. Therefore, other prophylactic and/or therapeutic methods are needed. Oxidative stress is involved in the neurodegenerative process accompanying both AMD and glaucoma; therefore, the use of antioxidant agents would clearly be beneficial, which is supported by the decreased prevalence and progression of AMD in patients adherent to a diet naturally rich in antioxidants. Dietary antioxidants are easily available and their use is based on the natural route of administration. Many preclinical studies both in vitro and using animal models of retinal degeneration showed the efficacy of dietary antioxidants, which was further proved in clinical trials. Resveratrol is beneficial both in AMD and glaucoma animal models, but confirmed only among AMD patients. For AMD, carotenoids and omega-3 fatty acids were also proved to be sufficient in preventing neurodegeneration. For glaucoma, coenzyme Q10 and alpha-lipoic acid showed efficacy for decreasing retinal ganglion cell loss and inhibiting the accompanying destructive processes. Interestingly, the benefits of vitamins, especially vitamin E was not confirmed, neither in preclinical nor in clinical studies.

The Causes and Frequency of Monocular and Binocular Blindness in Adults Applying to the Health Committee of a University Hospital in Central Anatolia

Objectives:

The aim of this study was to investigate the frequency of blindness and the pathologies that cause blindness in the Konya province of Turkey.

Materials and Methods:

The records of individuals over 18 years of age who applied to the health committee of Meram School of Medicine Hospital between January 2015 and December 2018 were evaluated retrospectively.

Results:

After reviewing the records of 4,268 applicants, a total of 222 applicants were included in the study (159 patients with monocular blindness, 63 patients with binocular blindness). The most common causes of monocular blindness were optic atrophy (13%), amblyopia (11%), and phthisis bulbi (10%). The most common causes of binocular blindness were retinitis pigmentosa (28%), proliferative diabetic retinopathy (13%), and unoperated cataract (11%). The frequency of monocular blindness was 3.7% (95% confidence interval [CI]: 3.2-4.3%) and binocular blindness was 1.5% (95% CI: 1.1-1.9%) in the sample. The frequency of blindness increased with age, with a positive correlation between mean age and blindness (p=0.002). Monocular blind applicants had a significantly lower mean age than binocular blind applicants (48.8±13.3 vs. 55.0±13.1 years, p=0.002) and binocular blind women had a significantly higher mean age than binocular blind men (62.7±16.0 vs. 53.2±11.7 years, p=0.023). The prevalence of monocular and binocular blindness was significantly higher in men than women (p=0.032).

Conclusion:

The results of this study show that many of the pathologies that cause blindness are preventable or treatable, and that blindness is associated with age.

Sustained-Release Microspheres of Rivoceranib for the Treatment of Subfoveal Choroidal Neovascularization

The wet type of age-related macular degeneration (AMD) accompanies the subfoveal choroidal neovascularization (CNV) caused by the abnormal extension or remodeling of blood vessels to the macula and retinal pigment epithelium (RPE). Vascular endothelial growth factor (VEGF) is known to play a crucial role in the pathogenesis of the disease. In this study, we tried to repurpose an investigational anticancer drug, rivoceranib, which is a selective inhibitor of VEGF receptor-2 (VEGFR2), and evaluate the therapeutic potential of the drug for the treatment of wet-type AMD in a laser-induced CNV mouse model using microsphere-based sustained drug release formulations. The PLGA-based rivoceranib microsphere can carry out a sustained delivery of rivoceranib for 50 days. When administered intravitreally, the sustained microsphere formulation of rivoceranib effectively inhibited the formation of subfoveal neovascular lesions in mice.

A Newly Identified Impairment in Both Vision and Hearing Increases the Risk of Deterioration in Both Communication and Cognitive Performance

Vision and hearing impairments are highly prevalent in adults 65 years of age and older. There is a need to understand their association with multiple health-related outcomes. We analyzed data from the Resident Assessment Instrument for Home Care (RAI-HC). Home care clients were followed for up to 5 years and categorized into seven unique cohorts based on whether or not they developed new vision and/or hearing impairments. An absolute standardized difference (stdiff) of at least 0.2 was considered statistically meaningful. Most clients (at least 60%) were female and 34.9 per cent developed a new sensory impairment. Those with a new concurrent vison and hearing impairment were more likely than those with no sensory impairments to experience a deterioration in receptive communication (stdiff = 0.68) and in cognitive performance (stdiff = 0.49). After multivariate adjustment, they had a twofold increased odds (adjusted odds ratio [OR] = 2.1; 95% confidence interval [CI]:1,87, 2.35) of deterioration in cognitive performance. Changes in sensory functioning are common and have important effects on multiple health-related outcomes.

Clinical and economic burden of neovascular age-related macular degeneration by disease status: a US claims-based analysis

BACKGROUND: New treatment alternatives have revolutionized the management of nAMD. However, there is limited evidence on the clinical and economic burden of nAMD in commercially insured US patients. OBJECTIVES: To examine the clinical and economic burden in patients with nAMD by disease status in the commercially insured US patient population and to identify drivers of nAMD-related costs. METHODS: Patients with at least 1 International Classification of Diseases, 10^th Revision Clinical Modification (ICD-10-CM) diagnosis for nAMD were identified from the IQVIA PharMetrics Plus database between April 2016 and August 2017 (index period). Patients had continuous enrollment for at least 6 months before and at least 12 months after the index date. Eye-level disease status was reported, along with intravitreal anti-VEGF treatment patterns. Health care resource utilization (HRU) (all-cause and nAMD-related) and direct health care costs were estimated over the 12 month follow-up period. Outcomes associated with falls and fractures were also assessed. Multivariate analysis identified drivers of annual nAMD-related outpatient costs among patients with anti-VEGF therapy. Incident patients (defined as those without an nAMD diagnosis 6 months prior to the index date) with at least 18 months of continuous enrollment after the index date were identified for a subset analysis to evaluate documented changes in disease status. RESULTS: A total of 6,076 patients with nAMD were identified for the prevalent cohort; 60.1%, 17.2%, and 5.9% had active CNV, inactive CNV, and inactive scar disease stage at index, respectively. The nAMD-related outpatient visit costs were roughly 4 and roughly 7 times higher, respectively, for the active CNV group ($8,658 [SD = $11,612]) compared with the inactive CNV ($2,406 [SD = $5,510]) and inactive scar ($1,198 [SD = $3,035]) groups (P < 0.0001). About 10% of prevalent patients had a fall/fracture claim over 12 months of follow-up. A total of 3,623 prevalent patients (59.6%) were eligible for the anti-VEGF treatment patterns analysis (mean [SD] duration of therapy = 7.7 [4.5] months; mean [SD] number of injections = 6.0 [3.7]). Qualified incident cases comprised 17.8% (n = 1,081) of the prevalent cohort. Approximately 20% of incident eyes with active CNV at baseline transitioned to inactive CNV. A total of 427 incident patients (39.5%) qualified for anti-VEGF treatment patterns analysis (mean [SD] duration of therapy = 6.2 [4.7] months, mean [SD] number of injections = 5.2 [3.5]). Significant drivers of total nAMD-related costs were the initial anti-VEGF agent and anti-VEGF injection frequency (P < 0.0001) in both prevalent and incident cohorts. CONCLUSIONS: The clinical and economic burden of nAMD treatment is substantial to the US healthcare system, where economic burden is higher among those with active CNV. Appropriate treatment may increase the duration of inactive disease periods and preserve visual acuity while lowering costs. DISCLOSURES: This study was funded by Allergan, an AbbVie Company. Allergan employees were involved in the study design, interpretation of data, writing of the manuscript, and the decision to submit for publication. Keyloun and Campbell are employees of Allergan. Multani, McGuiness, and Chen are employees of IQVIA, which received funding from Allergan for conducting the analysis. Almony and Shah-Manek have nothing to disclose.

The Association Between Objectively Measured Vision Impairment and Self-Reported Physical Activity Among 34,129 Adults Aged ≥50 Years in Six Low- and Middle-Income Countries

The authors investigated the association between vision impairment and physical activity among older adults from low- and middle-income countries. Visual acuity was measured using the tumbling ElogMAR chart, and vision impairment was defined as visual acuity worse than 6/18 (0.48 logMAR) in the better seeing eye. Physical activity was assessed by the Global Physical Activity Questionnaire. Multivariable logistic regression and meta-analysis were conducted to assess associations. The sample included 34,129 individuals aged 50-114 years (mean [SD] age 62.4 [16.0] years; 47.9% male). After adjustment for confounders, near vision impairment was not significantly associated with low physical activity, but far vision impairment showed a significant association (odds ratio = 1.32; 95% confidence interval [1.17, 1.49], I2 = 0.0%). Far vision impairment was dose-dependently associated with low physical activity (e.g., severe [<6/10] vs. no [≥6/12] far vision impairment; odds ratio = 1.80; 95% confidence interval [1.03, 3.15]). Interventions to address low levels of physical activity in the visually impaired in low- and middle-income countries should target those with far vision impairment.

Contrast Sensitivity in Early to Intermediate Age-Related Macular Degeneration (AMD)

PURPOSE

Previous studies indicated that advanced age-related macular degeneration (AMD) affects contrast sensitivity (CS) in humans. The CS results for early/intermediate AMD patients are contradictory. The purpose of this study was to determine if CS testing discriminates early/intermediate AMD patients with normal acuity from normal patients.

METHODS

Forty-nine subjects (25 control and 24 early/intermediate AMD patients) were chosen for this project. The age (p = .16) and acuity (p = .34) was not significantly different between the groups. The average simplified AREDS AMD grade for the AMD patients was 2.75 ± 1.03. Three CS functions employing a descending method of limits were measured at the fovea (1. stationary stimulus and, 2. 16 Hz counter-phase stimulus under photopic conditions and 3. the stationary stimulus viewed through a 2 log unit neutral density filter (mesopic condition, background luminance of 1 cd/m²)) and at 4 deg right or left of the fovea with a horizontally oriented sine wave grating (5 deg diameter) viewed on a VPixx monitor (luminance of 100 cd/m²).

RESULTS

The early AMD patients were no different from the control patients for any test condition. The intermediate AMD patients were significantly different from the control patients for the mesopic CS function (p = .05). Post-hoc 2-sample t-tests for the intermediate AMD patients were significantly different from the control patients under the stationary photopic and mesopic conditions for the 1.5 cycle per degree stimulus.

CONCLUSIONS

Group differences in CS were only found in intermediate AMD patients. The loss in CS increased for the intermediate AMD patients under low light levels. Thus, CS may not be the optimal test to discriminate early AMD from control patients so other tests measured under dark adapted conditions should be investigated.

Causes and Five-Year Proportion of New Irreversible Visual Impairment in Jinshan District, Shanghai, from 2009-2018

Purpose

To describe the age distribution and main causes of new registered irreversible visual impairment (VI) and to compare the five-year proportion of VI in Jinshan district, Shanghai, from 2009 to 2018.

Methods

The new irreversible VI data were collected in the registry system from the Disabled Persons' Federation in Jinshan district from January 1, 2009, to December 31, 2018. Age, gender, and causes of VI were included, and the 5-year proportion of VI was calculated.

Results

The peak occurrence of blindness occurred in the 50–59 yrs group in 2009–2013 and in the ≥70 yrs group in 2014–2018. The peak occurrence of low vision occurred in the 40–49 yrs group in 2009–2013 and in the 50–59 yrs group in 2014–2018. Myopic macular degeneration (MMD, 15.5%), diabetic retinopathy (DR, 14.3%), and other optic nerve atrophy (ONA, 14.3%) were the three leading causes of blindness in 2009-2013, whereas MMD (21.3%), age-related macular degeneration (AMD, 19.6%), ONA (14.9%) were the three leading causes of blindness in 2014–2018. MMD (39.2%), DR (9.6%), ONA (8.8%) were the three leading causes of low vision in 2009–2013, whereas MMD (38.7%), AMD (23.3%), ONA (7.4%) were the three leading causes of low vision in 2014–2018. The proportions of blindness and low vision caused by AMD were higher in 2014–2018 than those in 2009–2013 (P=0.034 and P < 0.001, respectively).

Conclusion

The present study demonstrated an increasing trend in the number of irreversibly visually impaired individuals from 2009 to 2018. More attention should be paid to people with high myopia and old age.

IMI Pathologic Myopia

Pathologic myopia is a major cause of visual impairment worldwide. Pathologic myopia is distinctly different from high myopia. High myopia is a high degree of myopic refractive error, whereas pathologic myopia is defined by a presence of typical complications in the fundus (posterior staphyloma or myopic maculopathy equal to or more serious than diffuse choroidal atrophy). Pathologic myopia often occurs in eyes with high myopia, however its complications especially posterior staphyloma can also occur in eyes without high myopia.

Owing to a recent advance in ocular imaging, an objective and accurate diagnosis of pathologic myopia has become possible. Especially, optical coherence tomography has revealed novel lesions like dome-shaped macula and myopic traction maculopathy. Wide-field optical coherence tomography has succeeded in visualizing the entire extent of large staphylomas. The effectiveness of new therapies for complications have been shown, such as anti-VEGF therapies for myopic macular neovascularization and vitreoretinal surgery for myopic traction maculopathy.

Myopia, especially childhood myopia, has been increasing rapidly in the world. In parallel with an increase in myopia, the prevalence of high myopia has also been increasing. However, it remains unclear whether or not pathologic myopia will increase in parallel with an increase of myopia itself. In addition, it has remained unclear whether genes responsible for pathologic myopia are the same as those for myopia in general, or whether pathologic myopia is genetically different from other myopia.

The Risks and Benefits of Myopia Control

PURPOSE

The prevalence of myopia is increasing around the world, stimulating interest in methods to slow its progression. The primary justification for slowing myopia progression is to reduce the risk of vision loss through sight-threatening ocular pathologic features in later life. The article analyzes whether the potential benefits of slowing myopia progression by 1 diopter (D) justify the potential risks associated with treatments.

METHODS

First, the known risks associated with various methods of myopia control are summarized, with emphasis on contact lens wear. Based on available data, the risk of visual impairment and predicted years of visual impairment are estimated for a range of incidence levels. Next, the increased risk of potentially sight-threatening conditions associated with different levels of myopia are reviewed. Finally, a model of the risk of visual impairment as a function of myopia level is developed, and the years of visual impairment associated with various levels of myopia and the years of visual impairment that could be prevented with achievable levels of myopia control are estimated.

RESULTS

Assuming an incidence of microbial keratitis between 1 and 25 per 10 000 patient-years and that 15% of cases result in vision loss leads to the conclusion that between 38 and 945 patients need to be exposed to 5 years of wear to produce 5 years of vision loss. Each additional 1 D of myopia is associated with a 58%, 20%, 21%, and 30% increase in the risk of myopic maculopathy, open-angle glaucoma, posterior subcapsular cataract, and retinal detachment, respectively. The predicted mean years of visual impairment ranges from 4.42 in a person with myopia of -3 D to 9.56 in a person with myopia of -8 D, and a 1-D reduction would lower these by 0.74 and 1.21 years, respectively.

CONCLUSIONS

The potential benefits of myopia control outweigh the risks: the number needed to treat to prevent 5 years of visual impairment is between 4.1 and 6.8, whereas fewer than 1 in 38 will experience a loss of vision as a result of myopia control.