The Prevalence of Open-Angle Glaucoma by Age in Myopia: The Korea National Health and Nutrition Examination Survey

The risk of open angle glaucoma in young adults with allergic diseases: a Nationwide cohort study

This study investigated the potential associations between allergic diseases (asthma, allergic rhinitis, and atopic dermatitis) and the development of primary open-angle glaucoma. We utilized authorized data from the Korean National Health Information Database (KNHID), which provides comprehensive medical claims data and information from the National Health Screening Program. We compared the baseline characteristics of subjects with and without allergic diseases and calculated the incidence and risk of glaucoma development. Cox proportional hazard regression analysis was used to determine the risk of glaucoma development in subjects with allergic diseases. A total of 171,129 subjects aged 20-39 with or without allergic diseases who underwent a general health examination between 2009 and 2015 were included. Subjects with allergic diseases exhibited a higher incidence of glaucoma compared to the control group. The hazard ratio (HR) of glaucoma onset was 1.49 and 1.39 in subjects with at least one allergic disease before and after adjusting for potential confounding factors, respectively. Among allergic diseases, atopic dermatitis showed the highest risk for glaucoma development (aHR 1.73) after adjusting for confounders. Allergic rhinitis showed an increased risk for incident glaucoma after adjustment (aHR 1.38). Asthma showed the lowest but still increased risk for glaucoma (aHR 1.22). The associations were consistent in all subgroup analyses stratified by sex, smoking, drinking, exercise, diabetes, hypertension, dyslipidemia, or history of steroid. In conclusion, allergic diseases are associated with increased risk of glaucoma development. Among allergic diseases, atopic dermatitis showed the highest risk for glaucoma development followed by allergic rhinitis and asthma.

Heterogenous thinning of peripapillary tissues occurs early during high myopia development in juvenile tree shrews

Myopia is an independent risk factor for glaucoma, but the link between both conditions remains unknown. Both conditions induce connective tissue remodeling at the optic nerve head (ONH), including the peripapillary tissues. The purpose of this study was to investigate the thickness changes of the peripapillary tissues during experimental high myopia development in juvenile tree shrews. Six juvenile tree shrews experienced binocular normal vision, while nine received monocular -10D lens treatment starting at 24 days of visual experience (DVE) to induce high myopia in one eye and the other eye served as control. Daily refractive and biometric measurements and weekly optical coherence tomography scans of the ONH were obtained for five weeks. Peripapillary sclera (Scl), choroid-retinal pigment epithelium complex (Ch-RPE), retinal nerve fiber layer (RNFL), and remaining retinal layers (RRL) were auto-segmented using a deep learning algorithm after nonlinear distortion correction. Peripapillary thickness values were quantified from 3D reconstructed segmentations. All lens-treated eyes developed high myopia (-9.8 ± 1.5 D), significantly different (P < 0.001) from normal (0.69 ± 0.45 D) and control eyes (0.76 ± 1.44 D). Myopic eyes showed significant thinning of all peripapillary tissues compared to both, normal and control eyes (P < 0.001). At the experimental end point, the relative thinning from baseline was heterogeneous across tissues and significantly more pronounced in the Scl (-8.95 ± 3.1%) and Ch-RPE (-16.8 ± 5.8%) when compared to the RNFL (-5.5 ± 1.6%) and RRL (-6.7 ± 1.8%). Furthermore, while axial length increased significantly throughout the five weeks of lens wear, significant peripapillary tissue thinning occurred only during the first week of the experiment (until a refraction of -2.5 ± 1.9 D was reached) and ceased thereafter. A sectorial analysis revealed no clear pattern. In conclusion, our data show that in juvenile tree shrews, experimental high myopia induces significant and heterogeneous thinning of the peripapillary tissues, where the retina seems to be protected from profound thickness changes as seen in Ch-RPE and Scl. Peripapillary tissue thinning occurs early during high myopia development despite continued progression of axial elongation. The observed heterogeneous thinning may contribute to the increased risk for pathological optic nerve head remodeling and glaucoma later in life.

Optic neuropathy in high myopia: Glaucoma or high myopia or both?

Due to the increasing prevalence of high myopia around the world, structural and functional damages to the optic nerve in high myopia has recently attracted much attention. Evidence has shown that high myopia is related to the development of glaucomatous or glaucoma-like optic neuropathy, and that both have many common features. These similarities often pose a diagnostic challenge that will affect the future management of glaucoma suspects in high myopia. In this review, we summarize similarities and differences in optic neuropathy arising from non-pathologic high myopia and glaucoma by considering their respective structural and functional characteristics on fundus photography, optical coherence tomography scanning, and visual field tests. These features may also help to distinguish the underlying mechanisms of the optic neuropathies and to determine management strategies for patients with high myopia and glaucoma.

Refractive surgery for the glaucoma suspect

PURPOSE OF REVIEW

The aim of this study was to provide an update on perioperative considerations in the evaluation and management of patients undergoing primary corneal and intraocular refractive procedures who are at risk for progressive glaucomatous optic neuropathy.

RECENT FINDINGS

The necessity of a comprehensive baseline assessment prior to refractive procedures with structural and functional testing, along with documentation of preoperative intraocular pressure (IOP) measurements, is highlighted in recent literature. Substantiation of the increased risk of postoperative IOP elevation in keratorefractive procedures in patients with higher baseline IOP and lower baseline CCT, but not necessarily the degree of myopia, has been variably evidenced. Tonometry methods which are less influenced by postoperative corneal structural change should be considered in patients undergoing keratorefractive procedures. Vigilence in postoperative monitoring for progressive optic neuropathy is suggested given evidence of an increased risk of steroid-response glaucoma in these patients. Additional evidence for the IOP-lowering impact of cataract surgery in patients with an increased risk of glaucoma is provided, irrespective of intraocular lens choice.

SUMMARY

Performing refractive procedures on patients at risk for glaucoma remains controversial. Definitive steps to optimize patient selection along with vigilance in disease state monitoring with longitudinal structural and functional testing can help mitigate potential adverse events.

Progress in clinical characteristics of high myopia with primary open-angle glaucoma

High myopia (HM) is a significant risk factor for the occurrence and progression of primary open-angle glaucoma (POAG). Identification with POAG in the HM population is an emergent challenge. Patients with HM have a significantly higher probability of complicating POAG than those without HM. When HM is associated with POAG, the changes to the fundus caused by both of them are confused with each other, making the diagnosis of early glaucoma difficult. This article reviews available researches on HM with POAG, summarizing the characteristics of the fundus structure such as epidemiology, intraocular pressure, optic disc, ganglion cell layer, retinal nerve fiber layer, vascular density, and visual field.

Global Tendency and Frontiers of Research on Myopia From 1900 to 2020: A Bibliometrics Analysis

Background:

Myopia is one of the most common causes of vision impairment in children and adults and has become a public health priority with its growing prevalence worldwide. This study aims to identify and evaluate the global trends in myopia research of the past century and visualize the frontiers using bibliometric analysis.

Methods

The literature search was conducted on the Web of Science for myopia studies published between 1900 and 2020. Retrieved publications were analyzed in-depth by the annual publication number, prolific countries and institutions, core author and journal, and the number of citations through descriptive statistics. Collaboration networks and keywords burst were visualized by VOSviewer and CiteSpace. Myopia citation network was visualized using CitNetExplorer.

Results

In total, 11,172 publications on myopia were retrieved from 1900 to 2020, with most published by the United States. Saw SM, from the National University of Singapore, contributed the most publications and citations. Investigative Ophthalmology &amp; Visual Science was the journal with highest number of citations. Journal of Cataract and Refractive Surgery with the maximum number of publications. The top 10 cited papers mainly focused on the epidemiology of myopia. Previous research emphasized myopia-associated experimental animal models, while recent keywords include “SMILE” and “myopia control” with the stronger burst, indicating a shift of concern from etiology to therapy and coincided with the global increment of incidence. Document citation network was clustered into six groups: “prevalence and risk factors of myopia,” “surgical control of myopia,” “pathogenesis of myopia,” “optical interventions of myopia,” “myopia and glaucoma,” and “pathological myopia.”

Conclusions

Bibliometrics analysis in this study could help scholars comprehend global trends of myopia research frontiers better. Hundred years of myopia research were clustered into six groups, among which “prevalence and risk factors of myopia” and “surgical control of myopia” were the largest groups. With the increasing prevalence of myopia, interventions of myopia control are a potential research hotspot and pressing public health issue.

The Association between Myopia and Primary Open-Angle Glaucoma: A Systematic Review and Meta-Analysis

BACKGROUND

Previous studies identified myopia as a risk factor for primary open-angle glaucoma (POAG). However, recent studies have shown different results, the definitive relationship between myopia and POAG remains controversial.

OBJECTIVES

To investigate the relationship between myopia and POAG.

METHODS

Published articles were searched from PubMed, Embase, and Scopus databases between 1970 and 2020. A pooled analysis of the ORs was performed using a random-effects model.

RESULTS

Data on the association between myopia and POAG, were obtained from 16 cross sectional studies, and the pooled OR was 2.26 (95% confidence interval [CI], 1.77 - 2.89, P < 0.001) in random effects model (I2 = 86%; P < 0.01). For the relationship of myopia and POAG progression, data from seven longitudinal cohort studies were included and the pooled OR was 0.85 (95% CI, 0.73 - 0.99, P = 0.042) in the random-effects model (I2 = 88%; P < 0.01).

CONCLUSION

Our findings demonstrated that myopia may be a risk factor associated with POAG and a possible protective factor for POAG progression. It may due to myopia with the presence of a lamina cribrosa defect slow down the visual field loss also POAG progression, further research for underlying mechanisms is still needed.

Research advance in optic disc tilt and rotation in high myopia and its implications for glaucoma and visual field defects

High myopia is of worldwide concern due to its high prevalence, and myopia is an independent risk factor for glaucoma. The purpose of this paper is to review the mechanism and clinical manifestations of optic disc tilt and rotation in high myopia and its relationship with glaucoma, to provide clues for monitoring fundus changes in high myopia and the early diagnosis of high myopia with glaucoma.

Clinical Utility of Bruch Membrane Opening-Minimum Rim Width for Detecting Early Glaucoma in Myopic Eyes

PRCIS

Bruch membrane opening-minimum rim width (BMO-MRW) is overall a useful parameter for diagnosing early glaucoma in myopic eyes.

PURPOSE

The aim of this study was to determine the diagnostic value of BMO-MRW compared with peripapillary retinal nerve fiber layer (pRNFL) thickness for detecting early glaucoma in patients with moderate to severe myopia.

METHODS

One eye was randomly selected from each of the 253 subjects (127 normal controls, 82 with glaucoma suspect, and 44 with early glaucoma). All patients underwent visual acuity testing, refractive error assessment, slit-lamp inspection, intraocular pressure measurement, fundus photography, perimetry. BMO-MRW and pRNFL thickness data were obtained using spectral-domain optical coherence tomography. Area under the receiver operating characteristic curves (AUC) for global and sectoral thickness parameters were calculated.

RESULTS

Global analyses for the discrimination of early glaucoma in all myopic subjects showed comparable AUCs between BMO-MRW and pRNFL thickness [AUC 0.952 (95% confidence interval, 0.918-0.975) and 0.934 (95% confidence interval, 0.896-0.961), respectively, P=0.345]. However, in sectoral analysis, BMO-MRW showed significantly better diagnostic performance than pRNFL thickness except for the superotemporal sector. The AUC for discriminating early glaucoma from glaucoma suspect, BMO-MRW showed statistically better diagnostic performance in the inferotemporal, inferonasal, superonasal, and nasal sectors. When dividing the subject based on a threshold Bruch membrane opening (BMO) area of 2.5 mm2, the diagnostic power of BMO-MRW was generally lower except for the inferonasal sector in the subgroup with a large BMO area.

CONCLUSIONS

BMO-MRW was overall a useful parameter for diagnosing early glaucoma in myopic eyes. However, its diagnostic performance was decreased in myopic eyes with large BMO and there were no significant differences from pRNFL thickness.

Influence of Chronic Ocular Hypertension on Emmetropia: Refractive, Structural and Functional Study in Two Rat Models

Chronic ocular hypertension (OHT) influences on refraction in youth and causes glaucoma in adulthood. However, the origin of the responsible mechanism is unclear. This study analyzes the effect of mild-moderate chronic OHT on refraction and neuroretina (structure and function) in young-adult Long-Evans rats using optical coherence tomography and electroretinography over 24 weeks. Data from 260 eyes were retrospectively analyzed in two cohorts: an ocular normotension (ONT) cohort (<20 mmHg) and an OHT cohort (>20 mmHg), in which OHT was induced either by sclerosing the episcleral veins (ES group) or by injecting microspheres into the anterior chamber. A trend toward emmetropia was found in both cohorts over time, though it was more pronounced in the OHT cohort (p < 0.001), especially in the ES group (p = 0.001) and males. IOP and refraction were negatively correlated at week 24 (p = 0.010). The OHT cohort showed early thickening in outer retinal sectors (p < 0.050) and the retinal nerve fiber layer, which later thinned. Electroretinography demonstrated early supranormal amplitudes and faster latencies that later declined. Chronic OHT accelerates emmetropia in Long–Evans rat eyes towards slowly progressive myopia, with an initial increase in structure and function that reversed over time.

Relationship between peripapillary choroidal thickness and retinal nerve fiber layer in young people with myopia

Aim

To study the characteristics and relationship between peripapillary retinal nerve fiber layer (RNFL) and choroidal thickness in young people with myopia.

Methods

We retrospectively analyzed 92 cases (52 myopia, 40 emmetropia) regarding age, sex, refractive power, axial length (AL), and intraocular pressure. Peripapillary RNFL and choroidal thicknesses were measured by optical coherence tomography (OCT) in six sectors. Differences in thicknesses between the two groups were compared by single-factor analysis.

Results

RNFL was thickest in the inferotemporal sector (157.3 ± 19.66 µm) and thinnest in the nasal sector (58.78 ± 18.41 µm). Peripapillary choroid was thickest in the superonasal sector (176.37 ± 33.92 µm) and thinnest in the inferotemporal sector (131.79 ± 25.22 µm). The RNFL was thinner in the myopia group (99.04 ± 8.23 µm) vs the emmetropia group (103.25 ± 8.32 µm); significantly different in the superotemporal and inferonasal sectors. Peripapillary choroid thickness in the myopia group (148.65 ± 26.64 µm) was lower vs the emmetropia group (160.88 ± 29.06 µm); significantly different in the nasal, inferonasal, and inferotemporal sectors. RNFL thickness was negatively correlated with choroidal thickness in the nasal sector (r = −0.288).

Conclusion

Peripapillary RNFL and choroidal thicknesses showed regional distributions. RNFL was negatively correlated with PCT in the nasal sector, possibly related to eye axis growth and choroidal compensation.

Study of the Prevalence of Glaucoma in Kazakhstan

BACKGROUND

Glaucoma is one of the leading causes of permanent visual disability around the world. However, the available literature lacks data on the prevalence of glaucoma in Central Asia, particularly in the Republic of Kazakhstan.

OBJECTIVE

The study was aimed at assessing the prevalence of glaucoma in the population of the Republic of Kazakhstan over 40 years old in 2019.

METHODS

A retrospective study was based on the analysis of the results of glaucoma screenings in 171 832 patients over 40 years old living in Kazakhstan (in 14 counties). Glaucoma cases were confirmed by Goldmann tonometry, fundus photography, and visual field testing. Demographic indicators, territorial differences, and hereditary predisposition were studied and analysed. In addition, blood pressure was measured.

RESULTS

Of 171 832 patients examined, 452 with verified glaucoma were identified. The average age of the patients was 63.9 ± 9.4. In rural areas, the prevalence of glaucoma was higher compared to the urban population. The overall prevalence of glaucoma among people over 40 years old was 2.37 ± 0.17. The prevalence of glaucoma among women was higher than for men, with an indicator of 1.91 (95% CI relative risk 1.78 - 2.03) (p < 0.05). The highest prevalence was found in the 71 - 75 age group [equals to 14.2% (95% CI 11.7 - 19.9)], with a statistically significant difference (p < 0.05). The highest prevalence of glaucoma was observed in the group of people with a hereditary predisposition, with an indicator of 14.7% (95% CI 0.6 - 1.9) (p < 0.05). Among all patients with concomitant arterial hypertension (n = 90, 19.9%), women (60%) compared with men (40%) had a 2.4% higher risk of glaucoma morbidity (95% CI 1.2% - 3.8%).

CONCLUSION

This study provides updated information on the prevalence of glaucoma in Kazakhstan. The results obtained confirm that the increase in the prevalence of glaucoma in Kazakhstan is directly proportional to the increase in the patients' age. These results showed the importance of screening for a timely diagnosis, especially for patients with high risk factors such as hereditary predisposition. Moreover, the results indicate that the early detection of systemic hypertension and increased intraocular pressure can be used for the prevention of undesirable outcomes such as an irreversible blindness.

Peripapillary choroidal thickness in eyes with high myopia

Objective

To investigate characteristics of peripapillary choroidal thickness (PCT) in Chinese patients with myopia without myopic maculopathy.

Methods

We retrospectively assessed 95 Chinese patients (95 eyes) with myopia without myopic maculopathy, who had visited the myopia clinic of Shandong Provincial Qianfoshan Hospital. Thirteen patients were excluded; the remaining 82 patients were divided into Groups 1 (spherical equivalent [SE], −0.5 to −6.0 D; axial length, 24–26 mm; n = 26), 2 (SE, −6.0 to −10.0 D; axial length, 26 to 28 mm; n = 34), and 3 (SE, ≥−10.0 D; axial length, ≥28 mm; n = 22). Enhanced depth imaging optical coherence tomography was used to measure PCT in inferior, superior, nasal, and temporal quadrants. Continuous variables were compared using one-way analysis of variance. Associations of PCT with SE and axial length were analyzed by Pearson correlation.

Results

PCT decreased with increasing SE and axial length in all quadrants. For each group, PCT was thickest in the temporal quadrant and thinnest in the inferior quadrant. PCT significantly differed between Groups 1 and 3 in superior, nasal, and temporal quadrants.

Conclusions

PCT decreased with increasing SE and axial length. PCT was thickest in the temporal quadrant and thinnest in the inferior quadrant in Chinese patients with myopia.

Profiles and Clinical Characteristics of Newly Diagnosed Glaucoma in Urban Korea: A Multicenter Study

Purpose

To explore the clinical characteristics and profiles of newly diagnosed glaucoma subtypes in urban Korea.

Methods

All newly diagnosed glaucoma patients enrolled in the participating ophthalmology outpatient clinics were included. A review of medical history including family history of glaucoma was conducted. The patients underwent complete ophthalmologic examinations including visual field test. The diagnosis of glaucoma was based on the International Society of Geographical and Epidemiological Ophthalmology criteria developed by glaucoma specialists.

Results

A total of 198,671 patients visited the participating ophthalmology outpatient clinics during the study period (from January 1, 2001 to June 30, 2016), of which 5,530 (2.8%) were diagnosed with glaucoma. The mean age of the newly diagnosed glaucoma patients was 52.0 ± 17.3 years (range, 6 to 89) and 2,830 patients were male (51.2%). The mean untreated intraocular pressure and vertical cup-to-disc ratio of the optic nerve head of newly diagnosed glaucoma eyes were 22.1 ± 10.6 mmHg and 0.66 ± 0.22, respectively. The most frequently observed subtypes of glaucoma were: normal tension glaucoma (33.0%) primary open-angle glaucoma (28.4%), ocular hypertension (11.1%), chronic angle-closure glaucoma (6.8%), neovascular glaucoma (5.2%), glaucoma associated with inflammation (3.8%), acute angle-closure glaucoma (3.3%), and glaucoma associated with aphakia or pseudophakia (2.2%).

Conclusions

Normal tension glaucoma was the most frequently observed glaucoma subtype in urban ophthalmology outpatient clinics in Korea.

Adduction-Induced Strain on the Optic Nerve in Primary Open Angle Glaucoma at Normal Intraocular Pressure

PURPOSE/AIM

The optic nerve (ON) becomes taut during adduction beyond ~26° in healthy people and patients with primary open angle glaucoma (POAG), but only retracts the globe in POAG. We used magnetic resonance imaging (MRI) to investigate this difference.

MATERIALS AND METHODS

MRI was obtained in 2-mm quasi-coronal planes in central gaze, and smaller (~23-25°) and larger (~30-31°) adduction and abduction in 21 controls and 12 POAG subjects whose intraocular pressure never exceeded 21 mmHg. ON cross-sections were analyzed from the globe to 10 mm posteriorly. Area centroids were used to calculate ON path lengths and changes in cross-sections to calculate elongation assuming volume conservation.

RESULTS

For both groups, ON path was nearly straight (<102.5% of minimum path) in smaller adduction, with minimal further straightening in larger adduction. ON length was redundant in abduction, exceeding 103% of minimum path for both groups. For normals, the ON elongated 0.4 ± 0.5 mm from central gaze to smaller adduction, and 0.4 ± 0.5 mm further from smaller to larger adduction. For POAG subjects, the ON did not elongate on average from central gaze to smaller adduction and only 0.2 ± 0.4 mm from smaller to larger adduction (P = .045 vs normals). Both groups demonstrated minimal ON elongation not exceeding 0.25 mm from central gaze to smaller and larger abduction. The globe retracted significantly more during large adduction in POAG subjects than normals (0.6 ± 0.7 mm vs 0.2 ± 0.5 mm, P = .027), without appreciable retraction in abduction. For each mm increase in globe axial length, ON elongation in large adduction similarly increased by 0.2 mm in each group.

CONCLUSIONS

The normal ON stretches to absorb force and avert globe retraction in adduction. In POAG with mild to severe visual field loss, the relatively inelastic ON tethers and retracts the globe during adduction beyond ~26°, transfering stress to the optic disc that could contribute to progressive neuropathy during repeated eye movements.

Effects of Consumption of Alcohol on Intraocular Pressure: Korea National Health and Nutrition Examination Survey 2010 to 2011

This study researched the association between alcohol consumption, intraocular pressure (IOP), and risk of open-angle glaucoma (OAG) using nationwide population-based cross-sectional data from the Korean population based survey. Information on alcohol intake was obtained by questionnaire and comprehensive ophthalmic examinations were performed. Among a total of 6057 participants, the prevalence of OAG was 4.4% (6.0% for men and 3.0% for women). Multivariate adjusted models showed that alcohol consumption showed significant relationship with changes in IOP. In sex-stratified analyses, alcohol consumption more than 2 times per week was associated with increased IOP in men without OAG, while in women with OAG drinking alcohol more than 4 times per week was associated with increased IOP. This study showed significant differences between men and women without glaucoma who consumed alcohol more than four times per week (p-value: 0.03). Our results suggest that alcohol consumption is associated with risk of elevated IOP depending on sex and presence of glaucoma in Koreans. Therefore, patients who need to control IOP should consider the effects of alcohol consumption.

Optic Nerve Traction During Adduction in Open Angle Glaucoma with Normal versus Elevated Intraocular Pressure

Purpose/Aim: We used magnetic resonance imaging (MRI) to investigate effects of intraocular pressure (IOP), race, and other factors on optic nerve (ON) traction in adduction, a phenomenon proposed as neuropathic in open angle glaucoma (OAG).Materials and Methods: Thirty-five patients with OAG (26 with maximal untreated IOP ≤21 mmHg, 9 with IOP >21mmHg) and 48 controls underwent axial and quasi-coronal MRI in central gaze and large (27-33°) abduction and adduction. Some underwent MRI at smaller ductions (21-28°). Effects of presence vs. absence of OAG; within OAG whether maximum IOP level was ≤21 mmHg vs. >21 mmHg; adduction angle; race; age; and gender on ON path length and globe translation were analyzed using generalized estimating equations to account for possible intereye correlations of individual subjects.Results: Average visual field mean deviation (±standard error of mean, SEM) was -8.2 ± 1.2 dB in OAG with normal IOP, and -6.1 ± 1.4 in high IOP. In central gaze, ON path in OAG was significantly more redundant than in controls but in both groups the ON became significantly and almost equally straighter in small (~21°) or large (~27°) adduction than in central gaze. With progressive adduction only, globes retracted in OAG (P < 0.005) but not in controls; this was only weakly related to globe size and not to IOP elevation. Globe retraction in adduction was significant only in OAG, and in that group was significantly greater in Asian than white patients (P < 0.02).Conclusions: Although ON tethering in adduction is normal, progressive adduction is associated with abnormal globe retraction in OAG regardless of IOP level. This phenomenon is more prominent in Asians who have OAG. Traction in adduction may cause repetitive strain injury to the ON and peripapillary sclera, thus contributing to the optic neuropathy of glaucoma independent of IOP.

Ocular biometric parameters are associated with non-contact tonometry measured intraocular pressure in non-pathologic myopic patients

PURPOSES

This research aimed to investigate effects and risk factors on non-contact tonometer (NCT) readings in healthy myopic subjects by employing cross-sectional study design.

METHODS

Totally, sixty otherwise healthy myopic volunteers (mean 28.4 years old) with 90% female were recruited in ophthalmic clinic. The routine ophthalmic tests, refractive evaluation, examination central corneal thickness (CCT), depth of anterior chamber, axial length, corneal curvature, white-to-white and NCT were assessed at baseline. The linear-mixed model was utilized to evaluate correlation between the readings and ocular biometric parameters.

RESULTS

For population in this study, mean spherical equivalents were - 4.85 ± 1.79 diopters in right eyes and - 4.63 ± 1.95 diopters in left eyes. Meanwhile, 28.3% of the eyes had a refractive error exceeding - 6.0 diopters. The mean NCT reading was 15.02 ± 3.02 mmHg in left eyes and 15.33 ± 2.96 mmHg in right eyes. Among the factors analyzed, CCT was the most significant parameter associated with NCT readings. After adjusting for the other factors, per one standard deviation increase of central corneal thickness (36.11 μm) was associated a 1.14 (95% confidence interval 0.53-1.77) mmHg elevated NCT reading. The average central corneal curvature, age and spherical equivalence were also significantly and independently associated with NCT readings.

CONCLUSIONS

Central corneal thickness, age, corneal curvature and degree of myopia were independently associated with NCT measured intraocular pressure. Central corneal thickness is one of the most influential factors.

Glaucoma in myopia: diagnostic dilemmas

Myopic eyes have an increased risk of glaucoma. However, glaucomatous changes in a myopic eye are often difficult to detect. Classic structural and functional investigations to diagnose glaucoma may be confounded by myopia. Here, we identify some of the common pitfalls in interpreting these structural parameters, and the possible solutions that could be taken to overcome them. For instance, in myopic eyes, we discuss the limitations and potential sources of error when using neuroretinal rim parameters, and retinal nerve fibre layer and ganglion cell-inner plexiform layer thickness measurements. In addition, we also review new developments and potential adjuncts in structural imaging such as the assessment of the retinal nerve fibre layer texture, and the examination of the microcirculation of the optic nerve head using optical coherence tomography angiography. For the functional assessment of glaucoma, we discuss perimetric strategies that may aid in detecting characteristic visual field defects in myopic glaucoma. Ultimately, the evaluation of glaucoma in myopia requires a multimodal approach, to allow correlation between structural and functional assessments. This review provides overview on how to navigate this diagnostic dilemma.

Socioeconomic Status and Glaucoma: Associations in High Levels of Income and Education

PURPOSE

Glaucoma affects millions of people globally, and socioeconomic status is known to be associated with glaucoma. This study expands the understanding of the relationship between socioeconomic factors and glaucoma.

METHODS

This study used Korean National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2012, with 24,664 persons who did not have missing records on the key variables. The combined relationship between levels of income and education and the prevalence of glaucoma was examined, as well as the occupational difference in the prevalence of glaucoma. Logistic regression models were constructed to generate odds ratios with 95% confidence intervals for predictors of glaucoma. All analyses were adjusted for strata, cluster, and weight.

RESULTS

The prevalence of glaucoma generally decreased with increasing levels of education and income, but this trend did not hold at the top two levels of education and income, wherein the prevalence was either the same or somewhat higher. Occupation types were shown to be significantly associated with glaucoma (p < 0.0001), and among all the occupations in the survey, farming/forestry/fishing showed the highest percentage of those with glaucoma (4.9%), and service/retail showed the lowest percentage (1.3%). In the multivariable adjusted model, the odds of glaucoma decreased with increasing income level, and increased at the highest income quartile, though the odds were significant only for the top two quartiles. The odds of glaucoma showed neither a nonlinear relationship nor statistical significance with education level when adjusted for other factors. In contrast, age and gender remained significant even after adjusting for other factors.

CONCLUSIONS

There exists a nonlinear relationship between key socioeconomic factors and the prevalence of glaucoma, though the exact nature of the relationship requires further investigation. These findings merit attention in studies that relate disease prevalence to education and income.

Comparison of peripapillary retinal nerve fiber layer thickness between myopia severity groups and controls

AIM

To compare the peripapillary retinal nerve fiber layer (RNFL) thickness measured via optical coherence tomography (OCT) between different groups of myopia severity and controls.

METHODS

This was a prospective cross-sectional study. All subjects underwent a full ophthalmic examination, refraction, visual field analysis and A-scan biometry. Myopic patients were classified as low myopia (LM) [spherical equivalent (SE) from greater than -0.5 D, up to -3.0 D], moderate myopia (MM; SE greater than -3.0 D, up to -6.0 D) and high myopia (HM; SE greater than -6.0 D). The control group consisted of emmetropic (EM) patients (SE from +0.5 D to -0.5 D). A Zeiss Cirrus HD-OCT machine was used to measure the peripapillary RNFL thickness of both eyes of each subject. The mean peripapillary RNFL thickness between groups was compared using both analysis of variance and analysis of covariance.

RESULTS

A total of 403 eyes of 403 subjects were included in this study. The mean age was 31.48±10.23y. There were 180 (44.7%) eyes with EM, 124 (30.8%) with LM, 73 (18.1%) with MM and 26 (6.5%) with HM. All groups of myopia severity had a thinner average RNFL than the EM group, but after controlling for gender, age, and axial eye length, only the HM group differed significantly from the EM group (P=0.017). Likewise, the superior, inferior and nasal RNFL was thinner in all myopia groups compared to controls, but after controlling for confounders, only the inferior quadrant RNFL was significantly thinner in the HM group, when compared to the EM group (P=0.017).

CONCLUSION

The average and inferior quadrant RNFL is thinner in highly myopic eyes compared to emmetropic eyes. Refractive status must be taken into consideration when interpreting the OCT of myopic patients, as RNFL thickness varies with the degree of myopia.

Progressive change in peripapillary atrophy in myopic glaucomatous eyes

Aim

To evaluate the progressive change in peripapillary atrophy (PPA) according to its shape and to explore the relationship between PPA progression and glaucoma worsening in myopic eyes.

Methods

A total of 159 eyes of 159 patients with myopic (axial length (AXL) >24 mm) glaucoma (mean follow-up 4.4 years, 35 eyes with minimal PPA, 40 concentric-type PPA eyes (>270° around the optic disc) and 84 eccentric-type PPA eyes (<270°)) were included. Sequential stereoscopic colour optic disc photographs were evaluated to qualitatively determine PPA progression. Factors associated with PPA progression were explored by Cox proportional hazard modelling in each PPA group.

Results

Patients with concentric PPA were older than patients with eccentric PPA (54.1±11.7 vs 44.1±11.7 years; P<0.001), and AXL was longer in the eccentric group than in the other groups (25.54±1.68 vs 25.28±1.53 vs 26.41±1.29 mm; P<0.001). Twenty-six eyes (65%) in the concentric group and 36 eyes (42.9%) in the eccentric group showed PPA progression. Older age (hazard ratio (HR) 1.059, P=0.008), worse baseline visual field mean deviation (HR 0.857, P=0.009) and greater baseline PPA area (HR 1.000, P=0.012) were associated with PPA progression in the concentric type. Glaucoma progression (HR 3.690, P=0.002) and longer AXL (HR 1.521, P=0.002) were associated with PPA progression in the eccentric type.

Conclusions

Relationship between glaucoma worsening and PPA progression was strongest in myopic glaucomatous eyes with eccentric type PPA.

[Secondary diseases in high myopia]

BACKGROUND

Eyes with high myopia (axial length ≥ 26.5 mm) do not just have a different size. Due to morphological and structural changes there is a considerably increased risk for many different secondary diseases.

OBJECTIVE

Determination of the incidence and mortality in high myopia, discussion of effects and clinical signs, presentation of treatment recommendations and counselling.

MATERIAL AND METHODS

A systematic search of the literature was carried out and a discussion on basic principles and epidemiological investigations is presented.

RESULTS

Findings due to high myopia are not in a closed state but undergo continuous changes. Choroidal neovascularization (adjusted prevalence 2.5-5%), staphyloma, foveoschisis and peripheral retinal degeneration are examples of problems contributing to the increased rate of visual impairment and blindness related to myopia. High myopia is associated with a clearly increased risk of retinal detachment after lens surgery (hazard ratio 6.1) and particularly more frequently in younger people. The associated primary open-angle glaucoma (odds ratio 2.46) is often recognized too late due to relatively low values of intraocular pressure.

CONCLUSION

Understanding of atrophic areas and staphyloma has benefited from recent advances in imaging (e.g. magnetic resonance imaging, optical coherence tomography and wide-field imaging) that complement and explain histological findings. Knowledge of the associated risk profile is of major clinical relevance.

Magnetic Resonance Imaging of Optic Nerve Traction During Adduction in Primary Open-Angle Glaucoma With Normal Intraocular Pressure

Purpose

We used magnetic resonance imaging (MRI) to ascertain effects of optic nerve (ON) traction in adduction, a phenomenon proposed as neuropathic in primary open-angle glaucoma (POAG).

Methods

Seventeen patients with POAG and maximal IOP ≤ 20 mm Hg, and 31 controls underwent MRI in central gaze and 20° to 30° abduction and adduction. Optic nerve and sheath area centroids permitted computation of midorbital lengths versus minimum paths.

Results

Average mean deviation (±SEM) was −8.2 ± 1.2 dB in the 15 patients with POAG having interpretable perimetry. In central gaze, ON path length in POAG was significantly more redundant (104.5 ± 0.4% of geometric minimum) than in controls (102.9 ± 0.4%, P = 2.96 × 10⁻⁴). In both groups the ON became significantly straighter in adduction (28.6 ± 0.8° in POAG, 26.8 ± 1.1° in controls) than central gaze and abduction. In adduction, the ON in POAG straightened to 102.0% ± 0.2% of minimum path length versus 104.5% ± 0.4% in central gaze (P = 5.7 × 10⁻⁷), compared with controls who straightened to 101.6% ± 0.1% from 102.9% ± 0.3% in central gaze (P = 8.7 × 10⁻⁶); and globes retracted 0.73 ± 0.09 mm in POAG, but only 0.07 ± 0.08 mm in controls (P = 8.8 × 10⁻⁷). Both effects were confirmed in age-matched controls, and remained significant after correction for significant effects of age and axial globe length (P = 0.005).

Conclusions

Although tethering and elongation of ON and sheath are normal in adduction, adduction is associated with abnormally great globe retraction in POAG without elevated IOP. Traction in adduction may cause mechanical overloading of the ON head and peripapillary sclera, thus contributing to or resulting from the optic neuropathy of glaucoma independent of IOP.

The association between socioeconomic status and visual impairments among primary glaucoma: the results from Nationwide Korean National Health Insurance Cohort from 2004 to 2013

Background

Glaucoma is one of the most leading causes of permanent visual impairments in Korea, and social expenses spent for the glaucoma are increasing. This study is to identify association between socioeconomic status and the visual impairments caused by primary glaucoma in Korea.

Methods

This study is based on a cohort study using stratified representative samples in the National Health Insurance claim data from 2002 to 2013 with 1,025,340 representative subjects. Target subjects were patients who are newly diagnosed with primary glaucoma from 2004 to 2013. We conducted a multiple logistic regression analysis depending on the occurrence of visual impairment and its temporal order compared to the glaucoma diagnosis.

Results

Among 1728 patients with primary glaucoma, those with low and middle income shows higher odds ratio (OR) of the visual impairments than those with high income group (low income; OR = 3.42, 95% Confidential Interval (CI):2.06–5.66, middle income; OR = 2.13, 95% CI: 1.28–3.55), in case of the occurrence of the visual impairments preceded the diagnosis of glaucoma.

Conclusions

Glaucoma patients without pre-existing glaucoma history before visual impairment have higher association between socioeconomic status and the occurrence of visual impairments by primary glaucoma. Since glaucoma had not been diagnosed and recognized yet, the differences may have been derived from the disparities of the awareness of the glaucoma. These findings call attention to the correlation between socioeconomic factors and the visual impairments by glaucoma, and raise public health needs over the importance of glaucoma awareness and eye screening for glaucoma, especially for low socioeconomic status.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-017-0551-y) contains supplementary material, which is available to authorized users.

Incidence of glaucomatous visual field loss after two decades of follow-up: the Rotterdam Study

To determine the incidence of glaucomatous visual field loss (GVFL) two decades after the start of the Rotterdam Study, and to compare known risk factors for open-angle glaucoma (OAG) between different clinical manifestations of OAG. Of 6806 participants aged 55 years and older from the population-based Rotterdam Study, 3939 underwent visual field testing at baseline and at least one follow-up round. The ophthalmic examinations included optic disc assessment and measurements of intraocular pressure (IOP), refractive error, diastolic blood pressure (DBP), and height and weight. The incidence rate of GVFL was calculated. Associations with the risk factors age, gender, baseline IOP, family history, myopia, DBP, and body-mass index [BMI] were assessed using Cox regression, with different clinical manifestations of OAG as outcome measure (glaucomatous optic neuropathy (GON), GVFL, GVFL and GON, GVFL without GON, and GON without GVFL). Median follow-up was 11.1 (IQR 6.8–17.2; range 5.0–20.3) years. The incidence rate of GVFL was 2.9 (95% confidence interval 2.4–3.4) per 1000 person years (140 cases with incident GVFL in one (n = 113) or both (n = 27) eyes). Baseline IOP and age were significantly associated with all OAG outcomes (all p < 0.001); BMI showed a non-significant protective effect in all outcomes (p = 0.01 to p = 0.09). Gender, myopia, and DBP were not associated with any outcome. Our study provides an estimate of the long-term incidence of GVFL in a predominantly white population. The development of GVFL was strongly associated with baseline IOP and age. Risk factor profiles were similar for the different outcomes.