Exploring the relationship between 24-2 visual field and widefield optical coherence tomography data across healthy, glaucoma suspect and glaucoma eyes

PURPOSE

To utilise ganglion cell-inner plexiform layer (GCIPL) measurements acquired using widefield optical coherence tomography (OCT) scans spanning 55° × 45° to explore the link between co-localised structural parameters and clinical visual field (VF) data.

METHODS

Widefield OCT scans acquired from 311 healthy, 268 glaucoma suspect and 269 glaucoma eyes were segmented to generate GCIPL thickness measurements. Estimated ganglion cell (GC) counts, calculated from GCIPL measurements, were plotted against 24-2 SITA Faster visual field (VF) thresholds, and regression models were computed with data categorised by diagnosis and VF status. Classification of locations as VF defective or non-defective using GCIPL parameters computed across eccentricity- and hemifield-dependent clusters was assessed by analysing areas under receiver operating characteristic curves (AUROCCs). Sensitivities and specificities were calculated per diagnostic category.

RESULTS

Segmented linear regression models between GC counts and VF thresholds demonstrated higher variability in VF defective locations relative to non-defective locations (mean absolute error 6.10-9.93 dB and 1.43-1.91 dB, respectively). AUROCCs from cluster-wide GCIPL parameters were similar across methods centrally (p = 0.06-0.84) but significantly greater peripherally, especially when considering classification of more central locations (p < 0.0001). Across diagnoses, cluster-wide GCIPL parameters demonstrated variable sensitivities and specificities (0.36-0.93 and 0.65-0.98, respectively), with the highest specificities observed across healthy eyes (0.73-0.98).

CONCLUSIONS

Quantitative prediction of VF thresholds from widefield OCT is affected by high variability at VF defective locations. Prediction of VF status based on cluster-wide GCIPL parameters from widefield OCT could become useful to aid clinical decision-making in appropriately targeting VF assessments.

A Systematic Review of Ophthalmology Education in Medical Schools: The Global Decline

TOPIC

This systematic review examined geographical and temporal trends in medical school ophthalmology education in relationship to course and student outcomes.

CLINICAL RELEVANCE

Evidence suggesting a decline in ophthalmology teaching in medical schools is increasing, raising concern for the adequacy of eye knowledge across the rest of the medical profession.

METHODS

Systematic review of Embase and SCOPUS, with inclusion of studies containing data on medical school ophthalmic course length; 1 or more outcome measures on student ophthalmology knowledge, skills, self-evaluation of knowledge or skills, or student course appraisal; or both. The systematic review was registered prospectively on the International Prospective Register of Systematic Reviews (identifier, CRD42022323865). Results were aggregated with outcome subgroup analysis and description in relationship to geographical and temporal trends. Descriptive statistics, including nonparametric correlations, were used to analyze data and trends.

RESULTS

Systematic review yielded 4596 publication titles, of which 52 were included in the analysis, with data from 19 countries. Average course length ranged from 12.5 to 208.7 hours, with significant continental disparity among mean course lengths. Africa reported the longest average course length at 103.3 hours, and North America reported the shortest at 36.4 hours. On average, course lengths have been declining over the last 2 decades, from an average overall course length of 92.9 hours in the 2000s to 52.9 hours in the 2020s. Mean student self-evaluation of skills was 51.3%, and mean student self-evaluation of knowledge was 55.4%. Objective mean assessment mark of skills was 57.5% and that of knowledge was 71.7%, compared with an average pass mark of 66.7%. On average, 26.4% of students felt confident in their ophthalmology knowledge and 34.5% felt confident in their skills.

DISCUSSION

Most evidence describes declining length of courses devoted to ophthalmology in the last 20 years, significant student dissatisfaction with courses and content, and suboptimal knowledge and confidence.

FINANCIAL DISCLOSURE(S)

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

Quantification and Predictors of Visual Field Variability in Healthy, Glaucoma Suspect, and Glaucomatous Eyes Using SITA-Faster

PURPOSE

The newly released Swedish Interactive Thresholding Algorithm (SITA)-Faster (SFR) has significantly shorter testing durations compared with older SITA algorithms, but its variability is uncertain. This study quantified and established threshold limits of test-retest variability across the 24-2 test grid using SFR.

DESIGN

Cross-sectional study with prospective longitudinal arm.

PARTICIPANTS

1426 eyes of 787 patients with healthy, suspected glaucoma, or manifest glaucoma eyes from hospital- and university- eye clinics.

METHODS

Two SFR tests per eye at a baseline visit and at two follow-up visits.

MAIN OUTCOME MEASURES

Pointwise variability measured by test-retest difference in pointwise sensitivity between tests one and two, mean global variability (test-retest variance) measured by average of pointwise variability for each participant, global sensitivity, and reliability indices of each eye.

RESULTS

Of the 1426 eyes, 540 eyes (37.9%) had a diagnosis of glaucoma, 753 eyes (52.8%) were suspected of having glaucoma, and the remaining 133 eyes (9.3%) were healthy. Of 74 152 pointwise sensitivities obtained, the mean test-retest difference was 2.17 ± 2.9 dB, whereas the mean test-retest variance for each participant was 2.17 ± 1.2 dB. Pointwise and global variability increased with worsening threshold sensitivity and (MD), respectively, and was greater for peripheral compared with central test locations. In the longitudinal cohort, no significant difference in mean test-retest variance was found across the 3 visits (mean variability, 2.10 dB vs. 2.16 dB vs. 2.16 dB at visits F0 vs. F1 vs. F2; P = 0.53, repeated-measures analysis of variance). Baseline MD (-0.19 dB; 95% CI, -0.22 to 0.16 dB; P < 0.0001) and abnormally high sensitivity on glaucoma hemifield test (1.14 dB; 95% CI, 0.78-1.51 dB; P < 0.0001) were significantly associated with increased variability. Finally, test-retest MD showed minimal change around the recommended 15% false-positive cutoff threshold.

CONCLUSIONS

The variability of SFR increases with worsening threshold sensitivity, is stable over time, and is greater for peripheral compared with central test locations. Worse baseline MD and abnormally high sensitivity are significant predictors of increased variability. A cutoff of 15% in false-positive results may be inappropriate as a threshold for judging test reliability in SFR.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Acute angle closure glaucoma misdiagnosed as sinusitis

A 69-year-old woman developed severe right suprabulbar pain with blurred right-sided vision. There were no haloes around lights, photophobia, nausea or vomiting. Investigations in the emergency department excluded a posterior communicating/internal carotid artery aneurysm. However, she did not have an ophthalmological assessment and the initial diagnosis was of sinusitis-related headache. An urgent ear, nose and throat assessment found no abnormality, but a local ophthalmologist subsequently diagnosed and managed the patient's acute angle closure crisis. Periocular pain always deserves detailed assessment with an accurate history, visual acuity assessment and intraocular pressure measurement.

Evaluation of the Consistency of Glaucomatous Visual Field Defects Using a Clustered SITA-Faster Protocol

PURPOSE

Frontloading SITA-Faster (SFR) visual fields (2 tests per eye on the same visit) has been shown to provide repeatable perimetric data at minimal time cost. This study reports the outcomes of using frontloaded SFR in the evaluation of pointwise visual field (VF) defects in a cohort of patients with glaucoma when transitioned from SITA-Standard (SS).

DESIGN

Prospective, cross-sectional study.

PARTICIPANTS

A total of 144 eyes of 91 patients with confirmed or suspected glaucoma who had an SS test on a previous visit.

METHODS

Two SFR tests (T1, T2) per eye on the same visit.

MAIN OUTCOME MEASURES

Global sensitivity, reliability indices, and pointwise deviation map probability scores from the pattern deviation grid of each patient were compared across the 3 sequential tests to evaluate the consistency of VF defects.

RESULTS

The mean age was 68.6 years, and 79.2% of patients had a diagnosis of glaucoma. There was no significant difference in mean deviation (MD) across the 3 tests (-5.83 decibels [dB], -5.28 dB, and -5.71 dB in SS, SFR1, and SFR2, respectively, repeated-measures analysis of variance [ANOVA], P = 0.48). The frontloaded SFR tests provided repeatable VFs that confirmed existing pointwise data on the SS in 4661 (62.3%) locations, reversed an SS defect in 614 (8.2%) locations, and demonstrated a new repeatable defect in 406 (5.4%) locations of the pattern deviation grid. A new defect of at least 3 contiguous points was identified in 20.1% of eyes. The non-repeatable points on the 2 SFR tests displayed no significant difference in the distribution of defect/nondefect points based on test order or peripheral versus central locations. There was no significant difference in the rate of obtaining at least 1 reliable test result between SS and the frontloaded SFR T1 and T2 (P = 0.77). Test duration significantly decreased from SS to SFR1/2 (379 vs. 160 vs. 158 seconds, P < 0.0001).

CONCLUSIONS

Frontloading SFR tests can provide repeatable data for the evaluation of the consistency of pattern deviation defects in glaucoma, with no observable decline in performance from test fatigue. This is achieved at equivalent duration and reliability as a single SS test. Frontloading SFR may be helpful in increasing testing frequency/quantity to meet recommended guidelines for progression analysis.

FINANCIAL DISCLOSURE(S)

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

Autonomous assessment of spontaneous retinal venous pulsations in fundus videos using a deep learning framework

The presence or absence of spontaneous retinal venous pulsations (SVP) provides clinically significant insight into the hemodynamic status of the optic nerve head. Reduced SVP amplitudes have been linked to increased intracranial pressure and glaucoma progression. Currently, monitoring for the presence or absence of SVPs is performed subjectively and is highly dependent on trained clinicians. In this study, we developed a novel end-to-end deep model, called U3D-Net, to objectively classify SVPs as present or absent based on retinal fundus videos. The U3D-Net architecture consists of two distinct modules: an optic disc localizer and a classifier. First, a fast attention recurrent residual U-Net model is applied as the optic disc localizer. Then, the localized optic discs are passed on to a deep convolutional network for SVP classification. We trained and tested various time-series classifiers including 3D Inception, 3D Dense-ResNet, 3D ResNet, Long-term Recurrent Convolutional Network, and ConvLSTM. The optic disc localizer achieved a dice score of 95% for locating the optic disc in 30 milliseconds. Amongst the different tested models, the 3D Inception model achieved an accuracy, sensitivity, and F1-Score of 84 ± 5%, 90 ± 8%, and 81 ± 6% respectively, outperforming the other tested models in classifying SVPs. To the best of our knowledge, this research is the first study that utilizes a deep neural network for an autonomous and objective classification of SVPs using retinal fundus videos.

High Polygenic Risk is Associated with Earlier Initiation and Escalation of Treatment in Early Primary Open Angle Glaucoma

PURPOSE

To assess whether a glaucoma polygenic risk score (PRS) was associated with treatment commencement or escalation in early primary open angle glaucoma.

DESIGN

Prospective longitudinal observational cohort study.

PARTICIPANTS

Participants from the PROGRESSA study (Progression Risk of Glaucoma: RElevant SNPs with Significant Association) were divided into a cohort of glaucoma suspects who were treatment naive at enrolment, and early manifest and suspect glaucoma cases on treatment at enrolment.

METHODS

A per-allele weighted glaucoma PRS was calculated for 1,107 participants. Multivariable mixed effects Cox proportional regression analysis assessed the association between PRS and time to commencement of intraocular pressure (IOP) lowering therapy in 416 glaucoma suspects who were treatment naive at study enrolment. Secondary analysis evaluated the association between PRS and escalation of IOP lowering therapy amongst 691 suspect and early manifest glaucoma cases who were on IOP lowering therapy at enrolment.

MAIN OUTCOME MEASURES

Commencement or escalation of IOP lowering therapy.

RESULTS

A higher glaucoma PRS was associated with a greater risk of commencing IOP-lowering therapy within 5 years (HR: 1.45/Standard Deviation (SD) 95% Confidence Interval (CI) [1.27, 1.62] P<0.001). This finding persisted after adjustment for relevant demographic and clinical parameters (adjusted HR: 1.23/SD 95%CI [1.07, 1.43] P=0.005). Participants in the upper population-based quintile had a 3.3 times greater risk of commencing therapy by 5 years than the lowest quintile (HR: 3.30 95%CI [1.63, 6,70] P<0.001), and a 5.4 greater risk of commencing IOP lowering therapy by 2 years than the lowest quintile (HR: 5.45 95%CI [2.08, 14.25] P<0.001). A higher glaucoma PRS was associated with a greater risk of treatment escalation amongst cases on treatment at enrolment (HR: 1.19/SD 95%CI [1.09, 1.31] P<0.001). In combined analysis of treatment naive suspects and treated cases, participants in the top population-based quintile were at 2.3 times greater risk of requiring initiation or escalation of IOP lowering therapy than the lowest quintile (HR: 2.33 95%CI [1.75, 3.01] P<0.001).

CONCLUSIONS

This study demonstrates novel associations between glaucoma polygenic risk and risk of commencement or escalation of IOP lowering therapy, building upon previous work highlighting the potential clinical utility of genetic risk stratification in glaucoma.

Physical Activity Is Associated With Macular Thickness: A Multi-Cohort Observational Study

Purpose

To assess the association between physical activity and spectral-domain optical coherence tomography (SD-OCT)-measured rates of macular thinning in an adult population with primary open-angle glaucoma.

Methods

The correlation between accelerometer-measured physical activity and rates of macular ganglion cell-inner plexiform layer (GCIPL) thinning was measured in 735 eyes from 388 participants of the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study. The association between accelerometer-measured physical activity and cross-sectional SD-OCT macular thickness was then assessed in 8862 eyes from 6152 participants available for analysis in the UK Biobank who had SD-OCT, ophthalmic, comorbidity, and demographic data.

Results

Greater physical activity was associated with slower rates of macular GCIPL thinning in the PROGRESSA study (beta = 0.07 µm/y/SD; 95% confidence interval [CI], 0.03-0.13; P = 0.003) after adjustment for ophthalmic, demographic and systemic predictors of macular thinning. This association persisted in subanalyses of participants characterized as glaucoma suspects (beta = 0.09 µm/y/SD; 95% CI, 0.03-0.15; P = 0.005). Participants in the upper tertile (greater than 10,524 steps/d) exhibited a 0.22-µm/y slower rate of macular GCIPL thinning than participants in the lower tertile (fewer than 6925 steps/d): -0.40 ± 0.46 µm/y versus -0.62 ± 0.55 µm/y (P = 0.003). Both time spent doing moderate/vigorous activity and mean daily active calories were positively correlated with rate of macular GCIPL thinning (moderate/vigorous activity: beta = 0.06 µm/y/SD; 95% CI, 0.01-0.105; P = 0.018; active calories: beta = 0.06 µm/y/SD; 95% CI, 0.006-0.114; P = 0.032). Analysis among 8862 eyes from the UK Biobank revealed a positive association between physical activity and cross-sectional total macular thickness (beta = 0.8 µm/SD; 95% CI, 0.47-1.14; P < 0.001).

Conclusions

These results highlight the potential neuroprotective benefits of exercise on the human retina.

Association Between Body Mass Index and Primary Open Angle Glaucoma in Three Cohorts

PURPOSE

To evaluate the relationship between body mass index (BMI) and glaucoma progression.

DESIGN

Multicohort observational study.

METHODS

This study combined a retrospective longitudinal analysis of suspect and early manifest primary open angle glaucoma cases from the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study with 2 replication cohorts from the UK Biobank and the Canadian Longitudinal Study of Ageing (CLSA). In the PROGRESSA study, multivariate analysis correlated BMI with longitudinal visual field progression in 471 participants. The BMI was then associated with glaucoma diagnosis and cross-sectional vertical cup-disc ratio (VCDR) measurements in the UK Biobank, and finally prospectively associated with longitudinal change in VCDR in the CLSA study.

RESULTS

In the PROGRESSA study, a lower BMI conferred a faster rate of visual field progression (mean duration of monitoring (5.28 ± 1.80 years (10.6 ± 3.59 visits) (β 0.04 dB/year/SD95% CI [0.005, 0.069]; P = .013). In the UK Biobank, a 1 standard deviation lower BMI was associated with a worse cross-sectional VCDR (β -0.048/SD 95% CI [-0.056, 0.96]; P < .001) and a 10% greater likelihood of glaucoma diagnosis, as per specialist grading of retinal fundus imaging (OR 0.90 95% CI [0.84, 0.98]; P = .011). Similarly, a lower BMI was associated with a greater risk of glaucoma diagnosis as per International Classification of Disease data (OR 0.94/SD; 95% CI [0.91, 0.98]; P = .002). Body mass index was also positively correlated with intraocular pressure (β 0.11/SD; 95% CI [0.06, 0.15]; P < .001). Finally, a lower BMI was then associated with greater VCDR change in the CLSA (β -0.007/SD; 95% CI [-0.01, -0.001]; P = .023).

CONCLUSIONS

Body mass index correlated with longitudinal and cross-sectional glaucomatous outcomes. This supports previous work illustrating a correlation between BMI and glaucoma.

Association of High Polygenic Risk With Visual Field Worsening Despite Treatment in Early Primary Open-Angle Glaucoma

Importance

Irreversible vision loss from primary open-angle glaucoma (POAG) can be prevented through timely diagnosis and treatment, although definitive diagnosis can be difficult in early-stage disease. As a consequence, large numbers of individuals with suspected glaucoma require regular monitoring, even though many of these may never develop disease and other high-risk individuals with suspected glaucoma may have delayed or inadequate treatment. POAG is one of the most heritable common diseases, and this provides an opportunity to use genetic instruments in risk-stratified screening, diagnosis, and treatment of early glaucoma.

Objective

To assess the association of glaucoma polygenic risk with glaucoma progression in early-stage disease.

Design, Setting, and Participants

This cohort study used clinical and genetic data obtained from a longitudinal cohort study, Progression Risk of Glaucoma: Relevant SNPs With Significant Association (PROGRESSA). Participants of European ancestry with characteristic optic nerve head changes suggestive of glaucoma were included. Data were collected between February 2012 and June 2020. Analysis took place between July 2020 and April 2022.

Main Outcomes and Measures

The association of a glaucoma polygenic risk score (PRS) (2673 uncorrelated variants) with rate of peripapillary retinal nerve fiber layer thinning on optical coherence tomography and progression of visual field loss on 24-2 Humphrey visual fields.

Results

A total of 1777 eyes from 896 individuals had sufficient data for structural progression analyses and 1563 eyes from 808 individuals for functional progression analyses. The mean (SD) age was 62.1 (9.9) years, 488 (44%) were male, and 1087 of 1103 individuals (98.5%) had European ancestry. An ancestrally matched normative population cohort (n = 17 642) was used for PRS reference. Individuals in the top 5% PRS risk group were at a higher risk of visual field progression compared with the remaining 95% after 5 years (hazard ratio, 1.5; 95% CI, 1.13-1.97; P = .005). Conversely, those in the bottom 20% PRS risk group were at a lower risk of visual field progression compared with an intermediate risk group over 3 years (hazard ratio, 0.52; 95% CI, 0.28-0.96; P = .04).

Conclusions and Relevance

In this study, high polygenic risk was associated with more rapid structural and functional progression in early POAG, despite more intensive treatment. A PRS may serve as a valuable adjunct to identify individuals who stand to benefit the most from more frequent surveillance and earlier or more intensive treatment.

Apparent Defective Abduction Without Diplopia

Sixth nerve palsies present with horizontal diplopia and typically have a neurological or neurovascular aetiology. They can be confirmed by clinically evaluating the velocity of the abducting saccade, which is slowed. Three cases are presented in which the patients had apparent defective abduction of one eye, resulting from not only neurological causes but also orbital causes. Clinicians should have a high index of suspicion in patients with defective abduction without diplopia and should include apparent defective abduction without diplopia (ADAD) in the list of potential differential diagnoses, considering not only neurological involvement but also orbital involvement.

The APOE E4 Allele Is Associated with Faster Rates of Neuroretinal Thinning in a Prospective Cohort Study of Suspect and Early Glaucoma

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Genetic Risk of Cardiovascular Disease Is Associated with Macular Ganglion Cell-Inner Plexiform Layer Thinning in an Early Glaucoma Cohort

PURPOSE

To evaluate the association between genetic risk for cardiovascular disease and retinal thinning in early glaucoma.

DESIGN

Prospective, observational genetic association study.

PARTICIPANTS

Multicohort study combining a cohort of patients with suspect and early manifest primary open-angle glaucoma (POAG), a cohort of patients with perimetric POAG, and an external normative control cohort.

METHODS

A cardiovascular disease genetic risk score was calculated for 828 participants from the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study. Participants were characterized as showing either predominantly macular ganglion cell-inner plexiform layer (GCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL) or equivalent macular GCIPL and pRNFL spectral-domain OCT thinning. The cardiovascular disease genetic risk scores for these groups were compared to an internal reference group of stable suspected glaucoma and of an external normative population. Replication was undertaken by comparing the phenotypes of participants from the Australia New Zealand Registry of Advanced Glaucoma (ANZRAG) with the normative control group.

MAIN OUTCOME MEASURES

Spectral-domain OCT and Humphrey Visual Field (HVF) change.

RESULTS

After accounting for age, sex, and intraocular pressure (IOP), participants with predominantly macular GCIPL thinning showed a higher cardiovascular disease genetic risk score than reference participants (odds ratio [OR], 1.76/standard deviation [SD]; 95% confidence interval [CI], 1.18-2.62; P = 0.005) and than normative participants (OR, 1.32/SD; 95% CI, 1.12-1.54; P = 0.002). This finding was replicated by comparing ANZRAG participants with predominantly macular GCIPL change with the normative population (OR, 1.39/SD; 95% CI, 1.05-1.83; P = 0.022). Review of HVF data identified that participants with paracentral visual field defects also demonstrated a higher cardiovascular disease genetic risk score than reference participants (OR, 1.85/SD; 95% CI, 1.16-2.97; P = 0.010). Participants with predominantly macular GCIPL thinning exhibited a higher vertical cup-to-disc ratio genetic risk score (OR, 1.48/SD; 95% CI, 1.24-1.76; P < 0.001), but an IOP genetic risk score (OR, 1.12/SD; 95% CI, 0.95-1.33; P = 0.179) comparable with that of the normative population.

CONCLUSIONS

This study highlighted the relationship between cardiovascular disease and retinal thinning in suspect and manifest glaucoma cases.

Practising refraction in ophthalmology: instructive or outdated? A prospective study and literature review

CLINICAL RELEVANCE

Many ophthalmologists preform clinical refactions, although little is known of the perceptions and practise of refraction by ophthalmologists and key barriers preventing this aspect of ophthalmic practice.

BACKGROUND

Although there are numerous studies on visual acuity in ophthalmology, there is no study to date on the practice of refraction by ophthalmologists. This study evaluates the practice patterns of ophthalmologists in current practice. It specifically addresses perceptions of ophthalmologists about (a) the importance of refraction in clinical practice, and (b) barriers to performing refraction. The methodology and frequency of performing refraction by ophthalmologists is also assessed.

METHODS

This cross-sectional study was conducted at the Annual Scientific Congress of the Royal Australian and New Zealand College of ophthalmologists in 2017, held in Perth, Australia. All attending ophthalmologists and ophthalmology trainees were invited to participate. Participants completed a 17-variable questionnaire on the perceptions of practitioners about refraction and their practice of it. Data were analysed using Microsoft Excel and IBM SPSS Version 24.

RESULTS

At this Congress, 213 attendees completed the survey, with most being consultant general ophthalmologists (85%). Twenty-six percent of participants either 'really loved' or 'liked' refracting patients. Those who reported feeling competent with refraction were more likely to perform it themselves (p = 0.001). Individuals most commonly reported taking 3-5 minutes to refract a patient (38%). Participants under the age of 65, and participants practising paediatric ophthalmology, were more likely to perform a refraction.

CONCLUSIONS

The literature indicates that this is the first study to describe the practice patterns of refraction by ophthalmologists. Although ophthalmologists found refraction important, the majority preferred patients to be refracted by others. Key barriers to ophthalmologists performing refraction included the time required to perform the refraction, a busy clinic, and the availability of alternative providers.

Subpalpebral Antibiotic Lavage as Safe, Emergent, and Cost-Effective Management of Acute Infectious Keratitis Related to Contact Lens Overwear: Case Report and Literature Review

PURPOSE

The aim of this study is to describe the technique of subpalpebral antibiotic lavage (SAL), which is a highly therapeutic, efficient, and cost-effective method for managing severe bacterial keratitis.

METHODS

This case report describes a 26-year-old woman with severe bacterial keratitis in the right eye due to contact lens overwear, with progressive corneal thinning, a hypopyon, impending perforation, and marked visual loss to perception of light despite treatment with intensive topical antibiotics. This was managed with SAL that involves the insertion of a cannula transcutaneously into the upper conjunctival fornix to provide continuous antibiotic irrigation of the ocular surface.

RESULTS

By 11 weeks after presentation, the cornea and anterior chamber appeared clinically quiescent, and visual acuity improved to 20/40 corrected in the right eye.

CONCLUSIONS

Bacterial keratitis is a potentially blinding condition for which contact lens wear is an important risk factor. Most cases are successfully managed with topical medications; however, in cases of treatment failure, a second-line approach such as SAL can be sight-saving. SAL uses readily available equipment for the delivery of high concentrations of antibiotics to the ocular surface, thus increasing therapeutic efficacy and reducing nursing staff workload. Despite its advantages, the literature reveals apparent underutilization of this technique.

Irritable bowel syndrome and risk of glaucoma: An analysis of two independent population-based cohort studies

OBJECTIVE

Irritable bowel syndrome (IBS) is a chronic disorder associated with an abnormal gastrointestinal microbiome. Microbiome-host interactions are known to influence organ function including in the central nervous system; thus, we sought to identify whether IBS may be a risk factor for the development of glaucoma.

DESIGN

Two prospective cohort studies.

SUBJECTS

The 1958 United Kingdom Birth Cohort (UKBC; 9091 individuals) and the Danish National Registry of Patients (DNRP; 62,541 individuals with IBS and 625,410 matched general population cohort members).

METHODS

In the UKBC, participants were surveyed throughout life (including at ages 42 and 50). The DNRP contains records of hospital-based contacts and prescription data from the national prescription database.

MAIN OUTCOME MEASURE

The main outcome measure was incidence of glaucoma. In the UKBC, incident glaucoma at age 50 (n = 48) was determined through comparison of survey responses at ages 42 and 50 years. In the DNRP, glaucoma was assessed by hospital diagnosis (n = 1510), glaucoma surgery (n = 582) and initiation of glaucoma medications (n = 1674).

RESULTS

In the UKBC, the odds ratio (OR) of developing glaucoma between ages 42 and 50 in persons with a chronic IBS diagnosis was increased [OR: 5.84, 95% confidence interval (CI): 2.26-15.13]. People with an IBS diagnosis in the DNRP had a hazard ratio (HR) of 1.35 for developing physician-diagnosed glaucoma (95% CI: 1.16-1.56), an HR of 1.35 for undergoing glaucoma surgery (95% CI: 1.06-1.70) and an HR of 1.19 for initiating glaucoma medication (95% CI: 1.03-1.38).

CONCLUSIONS

In two large European cohort studies, IBS is a risk factor for glaucoma.

Screening for Glaucomatous Visual Field Defects in Rural Australia with an iPad

Aim and objective

Developing improved methods for early detection of visual field defects is pivotal to reducing glaucoma-related vision loss. The Melbourne Rapid Fields screening module (MRF-S) is an iPad-based test, which allows suprathreshold screening with zone-based analysis to rapidly assess the risk of manifest glaucoma. The versatility of MRF-S has potential utility in rural areas and during infectious pandemics. This study evaluates the utility of MRF-S for detecting field defects in non-metropolitan settings.

Materials and methods

This was a prospective, multicenter, cross-sectional validation study. Two hundred and fifty-two eyes of 142 participants were recruited from rural sites through two outreach eye services in Australia. Participants were tested using MRF-S and compared with a reference standard; either Zeiss Humphrey Field Analyzer or Haag-Streit Octopus performed at the same visit. Standardized questionnaires were used to assess user acceptability. Major outcome measures were the area under the curve (AUC) for detecting mild and moderate field defects defined by the reference tests, along with corresponding performance characteristics (sensitivity, specificity).

Results

The mean test duration for MRF-S was 1.88 minutes compared with 5.92 minutes for reference tests. The AUCs for mild and moderate field defects were 0.81 [95% confidence interval (CI): 0.75–0.87] and 0.87 (95% CI: 0.83–0.92), respectively, indicating very good diagnostic accuracy. Using a risk criterion of 55%, MRF-S identified moderate field defects with a sensitivity and specificity of 88.4 and 81.0%, respectively.

Conclusion and clinical significance

The MRF-S iPad module can identify patients with mild and moderate field defects while delivering favorable user acceptability and short test duration. This has potential application within rural locations and amidst infectious pandemics.

How to cite this article

Chia MA, Trang E, Agar A, et al. Screening for Glaucomatous Visual Field Defects in Rural Australia with an iPad. J Curr Glaucoma Pract 2021;15(3):125–131.

Evaluation of the initial implementation of a nationwide diabetic retinopathy screening programme in primary care: a multimethod study

OBJECTIVES

The Australian Government funded a nationwide diabetic retinopathy screening programme to improve visual outcomes for people with diabetes. This study examined the benefits and barriers of the programme, image interpretation pathways and assessed the characteristics of people who had their fundus photos graded by a telereading service which was available as a part of the programme.

DESIGN

Multimethod: survey and retrospective review of referral forms.

SETTING

Twenty-two primary healthcare facilities from urban, regional, rural and remote areas of Australia, and one telereading service operated by a referral-only eye clinic in metropolitan Sydney, Australia.

PARTICIPANTS

Twenty-seven primary healthcare workers out of 110 contacted completed a survey, and 145 patient referrals were reviewed.

RESULTS

Manifest qualitative content analysis showed that primary healthcare workers reported that the benefits of the screening programme included improved patient outcomes and increased awareness and knowledge of diabetic retinopathy. Barriers related to staffing issues and limited referral pathways. Image grading was performed by a variety of primary healthcare workers, with one responder indicating the utilisation of a diabetic retinopathy reading service. Of the people with fundus photos graded by the reading service, 26.2% were reported to have diabetes. Overall, 12.3% of eyes were diagnosed with diabetic retinopathy. Photo quality was rated as excellent in 46.2% of photos. Referral to an optometrist for diabetic retinopathy was recommended in 4.1% of cases, and to an ophthalmologist in 6.9% of cases.

CONCLUSIONS

This nationwide diabetic retinopathy screening programme was perceived to increase access to diabetic retinopathy screening in regional, rural and remote areas of Australia. The telereading service has diagnosed diabetic retinopathy and other ocular pathologies in images it has received. Key barriers, such as access to ophthalmologists and optometrists, must be overcome to improve visual outcomes.

A combined convolutional and recurrent neural network for enhanced glaucoma detection

Glaucoma, a leading cause of blindness, is a multifaceted disease with several patho-physiological features manifesting in single fundus images (e.g., optic nerve cupping) as well as fundus videos (e.g., vascular pulsatility index). Current convolutional neural networks (CNNs) developed to detect glaucoma are all based on spatial features embedded in an image. We developed a combined CNN and recurrent neural network (RNN) that not only extracts the spatial features in a fundus image but also the temporal features embedded in a fundus video (i.e., sequential images). A total of 1810 fundus images and 295 fundus videos were used to train a CNN and a combined CNN and Long Short-Term Memory RNN. The combined CNN/RNN model reached an average F-measure of 96.2% in separating glaucoma from healthy eyes. In contrast, the base CNN model reached an average F-measure of only 79.2%. This proof-of-concept study demonstrates that extracting spatial and temporal features from fundus videos using a combined CNN and RNN, can markedly enhance the accuracy of glaucoma detection.