Vertical Cup-to-disc Ratio Research Articles

Optic Nerve Head Morphology in Adults Born Extreme, Very, and Moderate Preterm With and Without Retinopathy of Prematurity: Results From the Gutenberg Prematurity Eye Study

This study aimed to investigate associations of prematurity and associated factors with optic disc morphology in adulthood as long-term effects. Retrospective cohort study. The Gutenberg Prematurity Eye Study (GPES) is a retrospective cohort study with a prospective ophthalmologic examination of adults (age 18-52 years) in Germany. In every participant, photography of optic discs was performed with a nonmydriatic fundus camera, and optic disc measurements were done manually. The vertical cup-to-disc ratio (VCDR), optic disc area, and torted and tilted discs were assessed and exploratively compared between individuals with retinopathy of prematurity (ROP) with treatment, an ROP group without treatment and groups of individuals of different gestational ages (GAs) without ROP (GA ≤ 28 weeks, GA 29-32 weeks, GA 33-36 weeks, and GA ≥ 37 weeks [control group]). The present analysis included 743 eyes of 393 individuals born preterm and full-term (aged 28.4 ± 8.6 years, 223 females). The VCDR was significantly larger in subjects with a GA ≤28 weeks without ROP compared to the full-term control group (GA ≥37 weeks) (P=.002). Subjects with ROP without treatment also had a larger VCDR (P=.001), whereas those with ROP treatment showed a smaller VCDR than the full-term control group (P=.02). In addition, individuals with ROP treatment were more likely to have a torted disc than the full-term control group (P=.006). The present study provides evidence that individuals born extremely preterm have increased VCDR in adulthood. Furthermore, these results indicate that fetal origins affect optic disc morphology until adulthood, which might predispose the affected individual to degenerative optic nerve head diseases or being incorrectly diagnosed to glaucoma.

Effect of laser peripheral iridotomy on contrast sensitivity using Spaeth/Richman Contrast Sensitivity test.

Background:Laser peripheral iridotomy (LPI) is the current standard of care for primary angle-closure glaucoma. The existing literature lacks evidence regarding the effects of LPI on contrast sensitivity (CS) after the procedure.Objective:This study evaluates central and peripheral CS in patients undergoing LPI using the computer-based, Spaeth/Richman Contrast Sensitivity (SPARCS) test.Methods:We performed a pilot, prospective, interventional cohort study including 30 patients of primary angle-closure suspect (PACS) or primary angle closure (PAC) in both eyes. LPI was performed after a detailed history and clinical examination using standard procedure in all eyes. Intraocular pressure (IOP) and CS testing using SPARCS was performed before, 2 weeks and 3 months after LPI.Results:Data analyses revealed female predominance (66.67%, 20/30); the mean age of enrolled patients was 49.93 ± 10.43 years, and presenting acuity was 0.02 ± 0.06 (Log of Minimum Angle of Resolution [LogMAR]). The mean vertical cup-to-disc ratio (VCDR), mean deviation (MD in dB) and pattern standard deviation (PSD in dB) were 0.34 ± 0.09, –2.36 ± 1.72 and 2.34 ± 0.81, respectively. There was a statistically significant decrease between the pre- (15.17 ± 3.83 mmHg) and 2 weeks post-LPI (11.70 ± 1.53 mmHg) IOP (p < 0.001). However, CS in the pre- (73.47 ± 9.88) and 3 months post-LPI (75.20 ± 11.98) SPARCS scores did not reveal any statistical difference. The group-wise analysis showed a similar trend between PAC and PACS patients.Conclusion:LPI does not affect central as well as peripheral CS assessment in patients with the primary angle-closure disease.

A narrative review of glaucoma screening from fundus images

: The objective of the paper is to provide a general view for automatic cup to disc ratio (CDR) assessment in fundus images. As for the cause of blindness, glaucoma ranks as the second in ocular diseases. Vision loss caused by glaucoma cannot be reversed, but the loss may be avoided if screened in the early stage of glaucoma. Thus, early screening of glaucoma is very requisite to preserve vision and maintain quality of life. Optic nerve head (ONH) assessment is a useful and practical technique among current glaucoma screening methods. Vertical CDR as one of the clinical indicators for ONH assessment, has been well-used by clinicians and professionals for the analysis and diagnosis of glaucoma. The key for automatic calculation of vertical CDR in fundus images is the segmentation of optic cup (OC) and optic disc (OD). We take a brief description of methodologies about the OC and disc optic segmentation and comprehensively presented these methods as two aspects: hand-craft feature and deep learning feature. Sliding window regression, super-pixel level, image reconstruction, super-pixel level low-rank representation (LRR), deep learning methodologies for segmentation of OD and OC have been shown. It is hoped that this paper can provide guidance and bring inspiration to other researchers. Every mentioned method has its advantages and limitations. Appropriate method should be selected or explored according to the actual situation. For automatic glaucoma screening, CDR is just the reflection for a small part of the disc, while utilizing comprehensive factors or multimodal images is the promising future direction to furthermore enhance the performance.

Large-scale machine-learning-based phenotyping significantly improves genomic discovery for optic nerve head morphology

SummaryGenome-wide association studies (GWASs) require accurate cohort phenotyping, but expert labeling can be costly, time intensive, and variable. Here, we develop a machine learning (ML) model to predict glaucomatous optic nerve head features from color fundus photographs. We used the model to predict vertical cup-to-disc ratio (VCDR), a diagnostic parameter and cardinal endophenotype for glaucoma, in 65,680 Europeans in the UK Biobank (UKB). A GWAS of ML-based VCDR identified 299 independent genome-wide significant (GWS; p ≤ 5 × 10−8) hits in 156 loci. The ML-based GWAS replicated 62 of 65 GWS loci from a recent VCDR GWAS in the UKB for which two ophthalmologists manually labeled images for 67,040 Europeans. The ML-based GWAS also identified 93 novel loci, significantly expanding our understanding of the genetic etiologies of glaucoma and VCDR. Pathway analyses support the biological significance of the novel hits to VCDR: select loci near genes involved in neuronal and synaptic biology or harboring variants are known to cause severe Mendelian ophthalmic disease. Finally, the ML-based GWAS results significantly improve polygenic prediction of VCDR and primary open-angle glaucoma in the independent EPIC-Norfolk cohort.

Automated AI labeling of optic nerve head enables insights into cross-ancestry glaucoma risk and genetic discovery in >280,000 images from UKB and CLSA

Cupping of the optic nerve head, a highly heritable trait, is a hallmark of glaucomatous optic neuropathy. Two key parameters are vertical cup-to-disc ratio (VCDR) and vertical disc diameter (VDD). However, manual assessment often suffers from poor accuracy and is time intensive. Here, we show convolutional neural network models can accurately estimate VCDR and VDD for 282,100 images from both UK Biobank and an independent study (Canadian Longitudinal Study on Aging), enabling cross-ancestry epidemiological studies and new genetic discovery for these optic nerve head parameters. Using the AI approach, we perform a systematic comparison of the distribution of VCDR and VDD and compare these with intraocular pressure and glaucoma diagnoses across various genetically determined ancestries, which provides an explanation for the high rates of normal tension glaucoma in East Asia. We then used the large number of AI gradings to conduct a more powerful genome-wide association study (GWAS) of optic nerve head parameters. Using the AI-based gradings increased estimates of heritability by ∼50% for VCDR and VDD. Our GWAS identified more than 200 loci associated with both VCDR and VDD (double the number of loci from previous studies) and uncovered dozens of biological pathways; many of the loci we discovered also confer risk for glaucoma.

An Artificial-Intelligence- and Telemedicine-Based Screening Tool to Identify Glaucoma Suspects from Color Fundus Imaging.

Results The system achieved an accuracy of 89.67% (sensitivity, 83.33%; specificity, 93.89%; and AUC, 0.93). For external validation, the Retinal Fundus Image Database for Glaucoma Analysis dataset, which has 638 gradable quality images, was used. Here, the model achieved an accuracy of 83.54% (sensitivity, 80.11%; specificity, 84.96%; and AUC, 0.85). Conclusions Having demonstrated an accurate and fully automated glaucoma-suspect screening system that can be deployed on telemedicine platforms, we plan prospective trials to determine the feasibility of the system in primary-care settings.

Differences in clinical presentation of primary open-angle glaucoma between African and European populations.

PurposePrimary open‐angle glaucoma (POAG) has been reported to occur more frequently in Africans, and to follow a more severe course compared to Europeans. We aimed to describe characteristics of POAG presentation and treatment across three ethnic groups from Africa and one from Europe.MethodsWe ascertained 151 POAG patients from South African Coloured (SAC) and 94 South African Black (SAB) ethnicity from a university hospital in South Africa. In Tanzania, 310 patients were recruited from a university hospital and a referral hospital. In the Netherlands, 241 patients of European ancestry were included. All patients were over 35 years old and had undergone an extensive ophthalmic examination. Patients were diagnosed according to the ISGEO criteria. A biogeographic ancestry analysis was performed to estimate the proportion of genetic African ancestry (GAA).ResultsThe biogeographic ancestry analysis showed that the median proportion of GAA was 97.6% in Tanzanian, 100% in SAB, 34.2% in SAC and 1.5% in Dutch participants. Clinical characteristics at presentation for Tanzanians, SAB, SAC and Dutch participants, respectively: mean age: 63, 57, 66, 70 years (p < 0.001); visual acuity in the worse eye: 1.78, 1.78, 0.3, 0.3 LogMAR (p < 0.001); maximum intraocular pressure of both eyes: 36, 34, 29, 29 mmHg (p anova < 0.001); maximum vertical cup to disc ratio (VCDR) of both eyes: 0.90, 0.90, 0.84, 0.83 (p < 0.001); mean central corneal thickness: 506, 487, 511, 528 μm (p < 0.001). Fourteen percent of Tanzanian patients presented with blindness (<3/60 Snellen) in the better eye in contrast to only 1% in the Dutch.ConclusionIn this multi‐ethnic comparative study, Sub‐Saharan Africans present at a younger age with lower visual acuity, higher IOP, larger VCDR, than SAC and Dutch participants. This indicates the more progressive and destructive course in Sub‐Saharan Africans.

Comparison of vertical cup-to-disc ratio estimates using stereoscopic and monoscopic cameras.

The use of monoscopic cameras for glaucoma screening is increasing due to their portability, lower cost, and non-mydriatic capabilities. However, it is important to compare the accuracy of such devices with stereoscopic cameras that are used clinically and are considered the gold standard in optic disc assessment. The aim of this study is to compare vertical cup-to-disc ratio (VCDR) estimates obtained using images taken with a monoscopic and stereoscopic camera. Participants were selected from the Tema Eye Survey. Eligible subjects had images of at least one eye taken with two cameras. They were classified as meeting the glaucoma threshold if an eye had a VCDR estimate >97.5th percentile, corresponding to >0.725 for this population. Hence, we used 0.725 as the cutoff to group eyes into two categories: positive and negative. We calculated sensitivity, specificity, and predictive values of VCDR assessed by expert readers at a reading center for monoscopic photos using stereoscopic photos as the gold standard. Three hundred and seventy-nine eyes of 206 participants were included in the study. Most participants were female (60.2%) and the most common age group was 50-59 years (36.4%). Sixteen eyes met the glaucoma threshold (VCDR > 0.725). Of these, the VCDR estimates of 14 eyes (87.5%) disagreed on the glaucoma threshold from the two cameras. The sensitivity to detect glaucoma with the monoscopic camera was 14.3% (95% CI: 4.0, 40.3). The low sensitivity of monoscopic photos suggests that stereoscopic photos are more useful in the diagnosis of glaucoma.

The Appropriateness of Digital Diabetic Retinopathy Screening Images for a Computer-Aided Glaucoma Screening System.

PurposeThe purpose of this study was to evaluate the ability to screen for glaucoma using a Food Drug Administration (FDA) Class II diagnostic digital fundus photography system used for diabetic retinopathy screening (DRS).MethodsAll research participants underwent a comprehensive eye examination as well as non-mydriatic 45°single photograph retinal imaging centered on the macula. Optic nerve images within the 45° non-mydriatic and non-stereo DRS image were evaluated by two methods: 1) grading by three glaucoma specialists, and 2) a computer-aided automated segmentation system to determine the vertical cup-to-disc ratio (VCDR). Using VCDR from clinical assessment as gold standard, VCDR results from two methods were compared to that from clinical assessment. Inter-grader agreement was assessed by computing intraclass correlation coefficient (ICC). In addition, sensitivity and specificity were calculated.ResultsAmong 245 fundus photos, 166 images met quality specifications for analysis. Fifty images were not processed by the automated system due to the poor quality of the optic disc, and 29 images did not include the optic nerve head due to the patient movement during the photo acquisition. The ICC value for the VCDR between the gold standard clinical exam and the automated system was 0.41, indicating fair agreement. The ICC value between the three ophthalmologists and the gold standard was 0.51, 0.56, and 0.69, respectively, indicating fair to moderate agreement.DiscussionAssessing the VCDR on non-mydriatic and non-stereo DRS fundus photographs by either the computer-aided automated segmentation system or by glaucoma specialists showed similar fair to moderate agreement. In summary, optic nerve assessment for glaucoma from these 45° non-mydriatic and non-stereo DRS images is not yet suitable for tele-glaucoma screening.

Association between metabolic risk factors and optic disc cupping identified by deep learning method.

This study aims to investigate correlation between metabolic risk factors and optic disc cupping and the development of glaucoma. This study is a retrospective, cross-sectional study with over 20-year-old patients that underwent health screening examinations. Intraocular pressure (IOP), fundus photographs, Body Mass Index (BMI), waist circumference (WC), serum triglycerides, serum HDL cholesterol (HDL-C), serum LDL cholesterol (LDL-C), systolic blood pressure (BP), diastolic BP, and serum HbA1c were obtained to analyse correlation between metabolic risk factors and glaucoma. Eye with glaucomatous optic neuropathy(GON) was defined as having an optic disc with either vertical cup-to-disc ratio(VCDR) ≥ 0.7 or a VCDR difference ≥ 0.2 between the right and left eyes by measuring VCDR with deep learning approach. The study comprised 15,585 subjects and 877 subjects were diagnosed as GON. In univariate analyses, age, BMI, systolic BP, diastolic BP, WC, triglyceride, LDL-C, HbA1c, and IOP were significantly and positively correlated with VCDR in the optic nerve head. In linear regression analysis as independent variables, stepwise multiple regression analyses revealed that age, BMI, systolic BP, HbA1c, and IOP showed positive correlation with VCDR. In multivariate logistic analyses of risk factors and GON, higher age (odds ratio [OR], 1.054; 95% confidence interval [CI], 1.046-1.063), male gender (OR, 0.730; 95% CI, 0.609-0.876), more obese (OR, 1.267; 95% CI, 1.065-1.507), and diabetes (OR, 1.575; 95% CI, 1.214-2.043) remained statistically significant correlation with GON. Among the metabolic risk factors, obesity and diabetes as well as older age and male gender are risk factors of developing GON. The glaucoma screening examinations should be considered in the populations with these indicated risk factors.

Asian-specific vertical cup-to-disc ratio cut-off for glaucoma screening: An evidence-based recommendation from a multi-ethnic Asian population.

Evidence-based guidelines are essential for glaucoma screening to work effectively. To derive a vertical cup-to-disc ratio (VCDR) cut-off for glaucoma screening in a multi-ethnic Asian population. The Singapore Epidemiology of Eye Diseases (SEED) study is a population-based study conducted from 2004 to 2011 in a single tertiary care research institute. SEED comprised of 10 033 Chinese, Malay and Indian adults aged ≥40 (response rate 75.6%). After excluding participants with a history of glaucoma medication or surgery, 9673 participants were included for analysis. A systematic eye examination, which included applanation tonometry, visual field testing, gonioscopy and dilated fundus examination was conducted. Diagnosis of glaucoma. The distribution of VCDR and VCDR asymmetry were relatively homogenous in this multi-ethnic Asian population, with a 97.5th percentile value of 0.67 and 0.17, respectively. In the absence of more definite signs of glaucoma, VCDR ≥0.60 and VCDR asymmetry ≥0.20 provided the best balance between sensitivity (95.1%) and specificity (90.9%) in detecting glaucoma. For larger optic disc (≥2.0 mm), VCDR ≥0.65 with VCDR asymmetry ≥0.20 provided the best balance between sensitivity (84.8%) and specificity (93.2%). Overall, VCDR ≥0.60 with VCDR ≥0.20 asymmetry provides a good balance between sensitivity and specificity in detecting glaucoma. For larger optic disc, VCDR ≥0.65 should be considered instead to mitigate against false-referrals due to larger physiological disc cupping. Our findings may act as a reference to populations with similar VCDR distribution.

Intraocular pressure and circumpapillary retinal nerve fibre layer thickness in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA): distributions and associations

AimsTo describe the distributions of and associations with intraocular pressure (IOP) and circumpapillary retinal nerve fibre layer (cRNFL) thickness in a population-based study.MethodsNorthern Ireland Cohort for the Longitudinal Study of...

The agreement between optical coherence tomography angiography and non-mydriatic retinal camera in estimating the optic nerve head parameters and relations with the peripapillary vessel density in primary open-angle glaucoma.

To investigate the agreement between optical coherence tomography angiography (OCT-A) and non-mydriatic retinal camera (NMRC) in estimating the optic nerve head (ONH) parameters and evaluate the associations between peripapillary vessel density (VD) with ONH parameters assessed by both devices. The OCT-A and NMRC images of 262 participants (138 eyes were diagnosed with POAG, 63 were glaucoma suspect, and 61 were healthy subjects) were screened retrospectively. The vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio (CDAR), rim area (RA), disc area (DA), and cup volume (CV) were recorded using both devices. Peripapillary VD data were also recorded using OCT-A. The intraclass correlation coefficient (ICC) and Bland-Altman plots were obtained to investigate the agreement between the devices. Age- and intraocular pressure (IOP)-corrected associations between the VD and ONH parameters measured by the two devices were analyzed using linear regression models. ICC revealed excellent agreement for VCDR and CDAR, but poor agreement for RA, DA, and CV (ICC = 0.801, 0.793, 0.445, 0.298, and 0.527, respectively). The Bland-Altman plots showed poor agreement for VCDR and CDAR with a large span of limits of agreement (0.500 and 0.528, respectively) and significant proportional biases (P < 0.05). VD was found to be strongly associated with the VCDR and CDAR measurements of both devices (P < 0.001), but the associations were stronger for the measurements of NMRC. The disagreement between the devices should be considered in clinical practice. The associations between the VD and ONH parameters proved once again the importance of the ONH parameters in terms of the management of glaucoma patients.

P1277EFFECT OF HEMODIALYSIS ON PERIPAPILLARY CHOROIDAL THICKNESS AND OPTIC NERVE HEAD PARAMETERS MEASURED BY SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY

Abstract Background and Aims To investigate the effect of hemodialysis (HD) on peripapillary choroidal thickness (PCT) and optic nerve head (ONH) parameters by swept-source optical coherence (SS-OCT) and other ophthalmologic parameters in patients with end-stage kidney disease (ESKD). Method A prospective observational study was performed on 29 patients who underwent HD for ESKD. Detailed ophthalmologic examinations and SS-OCT were performed immediately before and after HD. The PCT were measured using the modification tool in the built-in OCT image viewer program. The ONH parameters including rim area (RA) and vertical cup-to-disc ratio (VCDR) were obtained using built-in software. Changes in PCT, and ONH parameters before and after HD were statistically analyzed. Results Average PCT significantly decreased from 127.3 ± 49.2 before HD to 117.1 ± 50.9 after HD (P&amp;lt;0.001). The RA increased and VCDR decreased significantly after HD (P=0.001 and P=0.027, respectively). Disc area did not show significant change after HD (P=0.648). Significant correlation was found between changes in PCT and changes in macular choroidal thickness (rho=0.547, P=0.002). Conclusion We observed significant decrease in PCT and significant changes in ONH parameters after HD. Our study suggest that HD can give influence on the ONH and its surrounding structure.

Relationship between optic disc hemorrhage and corneal hysteresis

ObjectiveTo determine the relationship between optic disc hemorrhage (DH) and corneal hysteresis (CH). MethodsConsecutive patients with prior or current photographic evidence of unilateral DH who had undergone CH measurement with the Ocular Response Analyzer (ORA; Reichert, Buffalo, NY) were enrolled. Eyes with a history of corneal disease, refractive surgery, or bilateral DH were excluded. Central corneal thickness (CCT), visual field data, 5 consecutive previous intraocular pressures (IOPs), and maximum documented peak IOP were obtained by chart review. Vertical cup-to-disc ratio (VCDR), the presence of neuroretinal rim notching, number of clock hours of beta zone parapapillary atrophy (ßPPA), and eye with greater ßPPA width were determined from photographs by 2 masked expert examiners. ResultsWe identified and analyzed 49 patients with photographically documented unilateral DH. Compared to fellow non-DH eyes, eyes with DH had lower CH (8.7 ± 1.9 vs 9.2 ± 1.7; p = 0.002), higher IOP (15.6 ± 3.6 vs 14.3 ± 4.1; p = 0.017), and greater VCDR (0.79 ± 0.13 vs 0.68 ± 0.23; p < 0.001), but were similar with respect to CCT, ßPPA extent, rim notching, peak IOP, and visual field damage (all p > 0.05). Using multivariate conditional logistic regression analysis, only CH (p = 0.012) and VCDR (p = 0.004) predicted the laterality of the DH. ConclusionsLower CH and greater VCDR are independently associated with DH. This suggests that CH may be a structural biomarker for an abnormality of the optic nerve complex that may be associated with progressive glaucoma. Eyes in which DH were detected had lower CH.

Agreement between Fourier-domain and swept-source optical coherence tomography used for optic nerve head measurements

To assess the correlation between optic nerve head measurements generated by Fourier-domain (FD) and swept-source (SS) optical coherence tomography (OCT) both in healthy Caucasian subjects and patients with primary open angle glaucoma (POAG). This was a cross-sectional study of the right eyes of 118 subjects. In each participant, the measurements of disc area, cup to disc ratio (CDR), vertical cup to disc ratio (VCDR), rim area and rim volume were performed consecutively by FD-OCT and then SS-OCT. Participant age, gender and spherical equivalent were also recorded. Agreement between the two devices was assessed through intraclass correlation coefficients (ICC) and Bland-Altman plots. The study sample consisted of 95 healthy eyes and 23 eyes with glaucoma. Mean participant age was 48.6±20.0 years, 54.2% were female, and mean spherical equivalent was -1.6±3.0 diopters. FD-OCT and SS-OCT measurements were respectively: mean disc area 1.79±0.3 vs 1.83±0.3 mm2 (ICC=0.71), mean CDR 0.38±0.2 vs 0.33±0.2 (ICC=0.91), mean VCDR 0.58±0.2 vs 0.52±0.2 (ICC=0.92), mean rim area 1.05±0.4mm2 vs 1.03±0.5mm2 (ICC=0.29), and mean rim volume 0.14±0.11 vs 0.21±0.17mm3 (ICC=0.53). Good agreement between the devices was noted for rim area and rim volume in glaucoma subjects (ICC=0.76 and 0.68 respectively), while weak agreement was observed for these variables in healthy subjects (ICC≤0.50). The CDR and VCDR measurements provided by FD and SS OCT showed excellent agreement for the overall sample. When the devices were used for rim measurements, agreement was excellent only in the POAG patients.

Comparison of Fundus Biomicroscopy Examination of the Optic Nerve Head with and without Mydriasis

Background: Notwithstanding the significant advances in automated imaging techniques in the past 2 decades, subjective evaluation of the optic disc still remains an important part of glaucoma propaedeutic. In places with limited resources and a high demand for ophthalmic care, anatomical evaluation of glaucoma cases often relies solely on slit-lamp-based fundus biomicroscopic examination, which is frequently performed without mydriasis. Objective: The aim of this study was to compare metrics related to fundus biomicroscopy examination of the optic nerve head and peripapillary retinal nerve fiber layer (pRNFL) with and without mydriasis. Material and Methods: Healthy individuals, patients with early glaucoma, and glaucoma suspects were prospectively enrolled. Patients were examined before and after mydriasis by three glaucoma specialists, who estimated patients’ vertical cup-to-disc ratio (CDR) and evaluated the presence of glaucomatous signs: laminar dot sign, disc hemorrhage, disc saucering, disc notching, peripapillary atrophy, localized pRNFL defect, and loss of the ISNT pattern. Main outcome measures were the intra-observer comparison, the inter-observer agreement, and the abilities to identify glaucomatous signs before and after mydriasis. Results: Thirty patients (60 eyes) were enrolled (mean age, 62.3 ± 11.6 years). Considering the evaluation of the three examiners, the mean vertical CDR increased from 0.41 to 0.44 (p = 0.02), and the median of the coefficient of variation of the measures was reduced from 0.24 to 0.11 (p = 0.01) after mydriasis. Regarding the inter-observer agreement evaluation, the kappa coefficient values ranged from 0.64 to 0.72 before mydriasis and from 0.71 to 0.77 after mydriasis. Dot sign and disc notching were better identified through fundoscopic examination with mydriasis compared to the nonmydriatic examination (p < 0.01). Conclusion: Our results suggest that fundus biomicroscopy should be performed with mydriasis whenever possible, as it yells a better intra- and inter-observer agreement and improves the detection of glaucomatous signs. Moreover, examiners seem to underestimate CDR values without mydriasis. Further investigation is warranted to validate these findings by general ophthalmologists and in different populations.

The distribution of vertical cup-to-disc ratio and its determinants in the Iranian adult population

PurposeTo determine the distribution of vertical cup-to-disc ratio (VCDR) and its relationship with ocular biometric indices. MethodsThis study was conducted in 4737 individuals aged 45–69 years living in Shahroud who participated in the second phase of Shahroud Eye Cohort Study in 2014. All participants underwent eye examinations including the measurement of visual acuity and refraction, slit-lamp biomicroscopy, retinal examination, and fundoscopy. Normality index was used to describe data distribution, and a multiple beta regression, with adjustment for the effect of cluster sampling, was applied to explore the relationship between VCDR and the study variables. ResultsThe mean [95% confidence interval (CI)] VCDR was 0.297 (0.293–0.301) in all participants; 0.296 (0.291–0.302) in men and 0.297 (0.292–0.302) in women. The highest mean VCDR was seen in the age group 55–59 years (0.299, 95% CI: 0.292–0.307). The 97.5th percentile was 0.600. According to multiple beta regression analysis, VCDR had a positive association with the female sex (P = 0.028), spherical equivalent (P < 0.001), cigarette smoking (P = 0.020), and axial length (P < 0.001), and had a negative association with hypertension (P = 0.001), best corrected visual acuity (P < 0.001), hyperlipidemia (P = 0.029) and anterior chamber depth (P = 0.001). ConclusionsThe mean VCDR and the 97.5th percentile were lower than most other studies. Although ethnicity and race may play a role in this difference, this difference should be considered in clinical decisions in the current population.

Does access to a portable ophthalmoscope improve skill acquisition in direct ophthalmoscopy? A method comparison study in undergraduate medical education

BackgroundDirect ophthalmoscopy (DO) is an essential skill for medical graduates but there are multiple barriers to learning this. Medical students and junior doctors typically lack confidence in DO. Most students do not own an ophthalmoscope and learn via ward devices that vary in design and usability. The Arclight ophthalmoscope (AO) is an easy to use, low-cost and portable device that could help address device access. This study aimed to assess the impact of personal ownership of an AO on DO skill acquisition and competency amongst medical students in the clinical environment.MethodsMethod comparison study with 42 medical students randomised to either traditional device ophthalmoscope (TDO) control or AO intervention group during an 18-week medical placement. Three objective assessments of DO competency were performed at the beginning and end of the placement: vertical cup to disc ratio (VCDR) measurement, fundus photo multiple-choice questions (F-MCQ) and model slide examination (MSE). DO examinations performed during the placement were recorded via an electronic logbook.ResultsStudents in both groups recorded a median number of six examinations each during an eighteen-week placement. There was no statistically significant difference between the groups in any of the objective assessment measures (VCDR p = 0.561, MCQ p = 0.872, Model p = 0.772). Both groups demonstrated a minor improvement in VCDR measurement but a negative performance change in F-MCQ and MSE assessments.ConclusionsStudents do not practice ophthalmoscopy often, even with constant access to their own portable device. The lack of significant difference between the groups suggests that device access alone is not the major factor affecting frequency of DO performance and consequent skill acquisition. Improving student engagement with ophthalmoscopy will require a more wide-ranging approach.

Appositional angle closure and conversion of primary angle closure into glaucoma after laser peripheral iridotomy

PurposeTo determine the relationship between appositional angle closure (AppAC) and the conversion of primary angle closure (PAC) into primary angle closure glaucoma (PACG) after laser peripheral iridotomy (LPI).MethodsConsecutive patients with...