Vertical Cup Disc Research Articles

Classifying juvenile onset primary open angle glaucoma using cluster analysis

AimTo classify unrelated patients with juvenile onset primary open angle glaucoma (JOAG) into clinically useful phenotypes using cluster analysis.MethodsOut of the 527 unrelated patients with JOAG, the study included 414...

Sonographic Assessment of Optic Disc Cupping and its Diagnostic Performance in Glaucoma.

The purpose of this study was to assess the optic cup diameter sonographically in glaucoma patients and in the normal population and correlate it with their photographic parameters to propose a cut-off value as a predictive index of glaucoma. A total of 95/50 primary open-angle glaucoma and 87/44 control patients with clear media underwent visual field assessment, fundus photography, and B-scan ultrasound. Photographic vertical cup diameter (PVCD) of cases and controls were recorded after magnification correction using the Bengtsson formula. Sonographic vertical cup diameter (SVCD) was measured in the vertical transverse position. The mean SVCD was 1.13±0.23 mm in glaucoma and 0.72±0.25 mm in controls (P=0.001). The mean PVCD was 1.024±0.199 mm in glaucoma and 0.636±0.217 mm in controls (P=0.001). A strong correlation between PVCD and SVCD in both groups was found (correlation coefficient r=0.857; P=0.001; glaucoma and r=0.795; P=0.001; control). SVCD had a positive correlation with vertical cup disc ratio (r=0.675; P=0.001 in glaucoma patients) and (r=0.797; P=0.001 in controls) cup area (r=0.798; P=0.001; glaucoma) and (r=0.727, P=0.001; control) a negative correlation with vertical neuroretinal rim diameter (r=-0.5187; P=0.000; glaucoma patients) and (r=-0.699; P=0.001; controls). No correlation of SVCD was found with severity of field grade changes. The receiving operative curve analysis was performed, and Youden's optimal cut-off method was used to find a cut-off value for SVCD, which came out to be 1.06, with 65.3% (95% confidence interval, 54.8-74.7) sensitivity and 94.3% (95% confidence interval, 87.1-97.1) specificity. The sonographic evaluation of the optic cup is a reliable noninvasive procedure and a potentially useful tool in the assessment of nonviewable suspected glaucomatous cups.

Pattern of steroid misuse in vernal keratoconjunctivitis resulting in steroid induced glaucoma and visual disability in Indian rural population: An important public health problem in pediatric age group.

Purpose:To know the pattern of presentations and management outcome of steroid induced glaucoma in vernal keratoconjunctivitis (VKC).Methods:Children of VKC using steroid with two of the following criteria were enrolled: Intraocular pressure (IOP) >21 mm Hg, glaucomatous optic disc and visual field defects. Misused topical steroids were classified in 4 groups; A- Highly potent drugs (dexamethasone, betamethasone), B- Moderate (prednisolone), C- Weak (loteprednol, fluorometholone), D- Unknown drugs. Active/conservative interventions were done to control IOP. Corrected distance visual acuity (CDVA), IOP, anterior segment and fundus examinations were noted. One-way ANOVA test and post hoc Tukey HSD test were used to compare the groups.Results:Out of 1423 VKC patients, 240 were using topical steroid without prescriptions. 92 eyes of 47 patients had steroid induced glaucoma. Hence prevalence of this complication was 3.30% in this study population. Mean age was 14.1 ± 3.8 years. Mean IOP was 38 ± 12 mm of Hg and mean vertical cup disc ratio was 0.67 ± 0.25. IOP was controlled by withdrawal of steroids (9 eyes), with antiglaucoma medications (27), trabeculectomy (57) and glaucoma drainage device (1). Mean CDVA at presentation was better in group C (0.23 log MAR). Mean IOP was highest in group A (43.1 mm Hg) followed by group D (40.5 mm Hg). At presentation 17 were blind (CDVA <3/60). Post treatment marginal improvement in CDVA was found (P = 0.46). However, statistically significantly improvement was noticed in IOP (P < 0.00001).Conclusion:Injudicious use of steroids leads to vision threatening complications like ocular hypertension and glaucoma in children of VKC. Weak steroids like loteprednol or fluorometholone should be used instead of higher potency drugs. Vision and IOP should be monitored fortnightly in children using topical steroids to detect steroid responders at the earliest.

Is community based case detection of glaucoma relevant? Intraocular Pressure level and vertical Cup Disc ratio of participants at a screening programme in a rural setting in Nigeria

Is community based case detection of glaucoma relevant? Intraocular Pressure level and vertical Cup Disc ratio of participants at a screening programme in a rural setting in Nigeria

Senile eye disease screening program in downtown Wenzhou: intraocular pressure

Objective: To investigate the distribution and related factors of intraocular pressure (IOP) in the screened population aged over 50 years in Wenzhou. Methods: This study included 31 170 community residents aged 50 years or older in Wenzhou undergoing screening from March 2014 to January 2016. Participants underwent a complete ocular examination, including visual acuity, eye-ground photography, slit lamp and standardized measurement of IOP by non-contact tonometry. Subjects who had undergone ocular operation or laser peripheral iridectomy, had glaucoma, corneal or other ocular diseases that could possibly affect the IOP, had an IOP lower than 6 mmHg(1 mmHg=0.133 kPa) and visual acuity less than 0.3, or had monocular IOP values were excluded. The relationship between IOP and various parameters were analyzed. Results: A total of 20 875 subjects (6 902 males and 13 973 females) were enrolled in the current analysis, including 18 677 healthy persons and 2 125 glaucoma suspects, with an average age of (67.3±8.7) years old. The mean IOP (mean±standard deviation) of the healthy population was (13.5±3.0) mmHg (13.4±3.2) mmHg in right eyes and (13.6±3.3) mmHg in left eyes; 2.04% of the left eyes, 1.51% of the right eyes and 2.92% of either eyes of healthy population had an IOP >21 mmHg. The mean IOP in glaucoma suspects was significantly higher than that in the healthy population (P<0.001); 6.78% of the left eyes, 6.16% of the right eyes and 9.65% of either eyes of glaucoma suspects had an IOP >21 mmHg. Men had lower IOPs than women [healthy population: (12.9±3.2) mmHg versus (13.7±3.2) mmHg; P<0.05]. The linear function of IOP (Y) with age (X(1)) and the vertical cup disc ratio (X(2)) was ^Y=15.962-0.043X(1)+0.837X(2)(P<0.05) in the healthy population. Conclusion: The IOP among healthy persons aged over 50 years living in downtown Wenzhou was decreased with age but increased with the vertical cup disc ratio. The IOP in females was higher than that in males. About 3% of the healthy population had an IOP greater than 21 mmHg. (Chin J Ophthalmol, 2018, 54: 586-592).

Association of serum uric acid levels with primary open-angle glaucoma: a 5-year case-control study.

It has been hypothesised that uric acid (UA) has a protective effect against oxidative damage in the central nervous system. Therefore, we investigated serum UA concentrations in patients with primary open-angle glaucoma (POAG) and explored the relationship between serum UA concentration and glaucoma severity. This prospective, cross-sectional, case-control study was conducted in 163 POAG patients and 103 normal controls. Clinical and demographic information was obtained from the medical data platform of the Eye & ENT Hospital of Fudan University, Shanghai, China. The POAG patients were categorised into mild [median deviation (MD)≤6.00dB], moderate (MD>6 Db-≥12dB) and severe (MD>12dB) subgroups, based on their visual field MD results. The level of serum UA in the POAG group (0.321±0.084mmol/l) was approximately 12.77% lower (p<0.001) than that of the control group (0.362±0.053mmol/l). The UA/creatinine (Cr) ratio was approximately 14.99% lower (p<0.001) in patients with POAG (4.47±1.15), compared with the control group (5.14±1.05). The mean level of UA was lowest in the severe POAG group, followed by the moderate POAG group, and the mild POAG group (p<0.001). A similar trend was observed when UA levels were compared between the POAG and control groups in males. Multivariate regression analyses showed a significant negative correlation between UA and vertical cup-disc ratio (B=-0.320, p=0.034), and UA and MD (B=-0.441, p=0.031) in males. Primary open-angle glaucoma patients have lower UA levels; however, a negative association between UA levels and disease severity was evident in male patients.

Association between polymorphism of optic disc related genes and susceptibility to primary open angle glaucoma in Inner Mongolia

Objective To evaluate the association between polymorphism of the optic disc related genes and primary open angle glaucoma (POAG) in Inner Mongolia. Methods A retrospective study was adopted.Pathography on 108 POAG patients was collected from six hospitals in Hohhot, Baotou city from January, 2014 to December, 2016 as POAG group.At the same time, 120 healthy persons were included as the control group.Fasting venous blood of 2 ml blood was collected by EDTA anticoagulant.Mass spectrometry was used to genotype the single nucleotide polymorphism (SNPs) of RFTN1 (rs690037), ATOH7 (rs7916697, rs3858145), CDC7 (rs1192415), CDKN2B (rs1063192) and SIX (rs10483727) in 108 patients with POAG and 120 normal controls.The association of gene polymorphism with POAG was analyzed by the χ2 test and logistic regression analysis.The study protocol was approved by the Ethics Committee of Inner Mongolia Baogang Hospital, and written informed consent was obtained from each patient. Results The frequency of CDKN2B (rs1063192) G allele in the POAG group was significantly higher than that in the control group (27% VS.17%, odds ratio[OR]=1.824, 95% confidence interval [CI]: 1.163-2.861, P=0.008), whereas allele frequencies of the other 7 SNPs were not statistically different between the two groups (all at P>0.05). Additive and dominant models of rs1063192 indicated that the individual with G allele was more likely to suffer from POAG, with a significant difference (P 0.05). There was no significant difference in the distribution of other SNPs genotypes between the POAG group and the control group (P>0.05). Conclusions The polymorphism of CDKN2B (rs1063192) is associated with the susceptibility to POAG, and the minor G allele may increase the risk of POAG. Key words: Primary open angle glaucoma; Optic disc area; Vertical cup disc ratio; Polymorphism

The relationship between vertical cup–disc ratio and body mass index in a population of adult Saudi females

Purpose: The vertical cup–disc (C/D) ratio is useful clinically in optic-disc assessment in glaucoma suspects and diagnosing glaucomas and is thought to also be influenced by many ocular and systemic factors. The body mass index (BMI) is said to be an important parameter which influences vertical C/D ratio and different studies have shown different correlation between these two variables. The aim of the study was to assess the relationship of vertical C/D ratio with BMI in a population of Saudi adult females. Methods: One hundred and one female participants in the age group 18 to 40 years were included in a cross-sectional study after obtaining information regarding demographic data, ocular/systemic diseases, and surgeries by an oral interview. The BMI was calculated as ratio of body weight divided by the square of the body height. C/D ratio was recorded with direct ophthalmoscopic examination and examination with 90-D (Volk) lens. Analysis of variance was used to examine the BMI on vertical C/D ratio. A P-value <0.05 was considered to be statistically significant with confidence interval of 95%. Results: The mean BMI was 22.7 (±4.49) and the mean C/D ratio was 0.22 (±0.14). No significant relationship between increasing vertical C/D ratio and BMI P-value 0.154 was found. Conclusion: This study, conducted as a pilot study to investigate the relationship between C/D ratio and BMI in a young female Saudi population, found no significant relationship between vertical C/D ratio and BMI. This relationship is important as it helps to rule out effect of BMI on C/D ratio parameters in this population.

The impact of primary open-angle glaucoma: Quality of life in Indian patients.

Purpose:Glaucoma significantly affects the quality of life (QoL) of a patient. Despite the huge number of glaucoma patients in India, not many, QoL studies have been carried out. The purpose of the present study was to evaluate the QoL in Indian patients with varying severity of glaucoma.Methods:This was a hospital-based, cross-sectional, analytical study of 180 patients. The QoL was assessed using orally administered QoL instruments comprising of two glaucoma-specific instruments; Glaucoma Quality of Life-15 (GQL-15) and Viswanathan 10 instrument, and 1 vision-specific instrument; National Eye Institute Visual Function Questionnaire-25 (NEIVFQ25).Results:Using NEIVFQ25, the difference between mean QoL scores among cases (88.34 ± 4.53) and controls (95.32 ± 5.76) was statistically significant. In GQL-15, there was a statistically significant difference between mean scores of cases (22.58 ± 5.23) and controls (16.52 ± 1.24). The difference in mean scores with Viswanathan 10 instrument in cases (7.92 ± 0.54) and controls (9.475 ± 0.505) was also statistically significant. QoL scores also showed moderate correlation with mean deviation, pattern standard deviation, and vertical cup-disc ratio.Conclusion:In our study, all the three instruments showed decrease in QoL in glaucoma patients compared to controls. With the increase in severity of glaucoma, corresponding decrease in QoL was observed. It is important for ophthalmologists to understand about the QoL in glaucoma patients so as to have a more holistic approach to patients and for effective delivery of treatment.

Comparison of the Variation in Stereoscopic Vertical Cup Disc Ratio Examination with 90 D lens vs. Cirrus HD-OCT

Aim: To compare the variation in stereoscopic vertical cup disc ratio examination with 90 D lens Vs. Cirrus HDOCT. Material and Methods: This is a retrospective study of all cases in which Cirrus HD-OCT was done for glaucomatous disc evaluation in the month of January 2016 and examined by single experienced glaucoma specialist. It includes 94 eyes of 49 patients (4 patients were one eyed). Difference of vertical cup disc ratio between 90 D and Cirrus HD-OCT was noted, values less than 0.1 were considered as comparable while the values more than or equal to 0.1 were considered as non-comparable. Results: Age of the patients was 44.26 ± 17.89 years (mean ± SD). Out of 49 patients, 65.31% (32) were males and 34.69% (17) were females. Vertical Cup disc ratio was comparable in 92.55% (87) and found to be noncomparable in 7.45% (7) of eyes with Cirrus HD-OCT. Conclusion: Stereoscopic vertical cup disc ratio examination with 90 D lens was found to be comparable with Cirrus HD-OCT in majority of the cases.

An Observational Study Comparing the Correlation of Vertical Cup Disc Ratio and Disc Damage Likelihood Scale with Visual Field Changes and Central Corneal Thickness in Primary Open Angle Glaucoma Patients

An Observational Study Comparing the Correlation of Vertical Cup Disc Ratio and Disc Damage Likelihood Scale with Visual Field Changes and Central Corneal Thickness in Primary Open Angle Glaucoma Patients

Interocular symmetry of retinal nerve fiber layer and optic nerve head parameters measured by Cirrus high-definition optical coherence tomography in a normal pediatric population.

Purpose:To determine interocular differences in the retinal nerve fiber layer (RNFL) and optic nerve head (ONH) parameters in a pediatric population using Cirrus high-definition optical coherence tomography (HD-OCT).Methods:Seventy normal Indian children aged 5–17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. All subjects underwent a comprehensive ophthalmologic examination and an evaluation of the RNFL and ONH by Cirrus HD-OCT. Differences between the right and left eyes were calculated and values were compared by means of a paired t-test. Subjects were also divided into two groups based on age (under or over 10 years of age). Interocular differences in RNFL and ONH parameters together with sex and age variations for these differences were determined.Results:The mean age of studied pediatric population was 11.83 ± 3.3 years (range 5–17). Average RNFL thickness was 94.46 ± 8.7 μm (± SD) (range 77–111). Differences in the average RNFL between right and left eyes were not statistically significant (P = 0.060). Superior quadrant RNFL was thicker in the left eye and temporal quadrant was thicker in the right eye. Among ONH parameters, there were no statistically significant differences in any parameters, except vertical cup-disc (CD) ratio which was significant (P = 0.007). The 2.5%–97.5% limits of asymmetry were 9 μm for average RNFL, 0.14 for average CD ratio, and 0.22 for vertical CD ratio. Mean interocular RNFL thickness differences in superior, superior nasal, and temporal superior quadrants were 10.61 (P < 0.001), 12.57 (P < 0.001), and 4.46 (P = 0.002) μm, respectively. Interocular nerve fiber layer thickness differences were not significantly correlated with sex, while only significant differences with age were observed in 12 clock hour sector analysis, mainly in nasal inferior and inferior quadrant.Conclusions:We report the degree of interocular symmetry of RNFL and ONH parameters measured by Cirrus HD-OCT in a healthy pediatric population. The normal interocular RNFL asymmetry should not exceed 9 μm and vertical CD ratio beyond 0.22 should be considered for further investigations. The physiologic asymmetry provided by this study may assist in identifying changes in RNFL thickness and ONH parameters in pediatric glaucoma and ONH disorders.

Comparison of Peripapillary Retinal Nerve Fiber Layer (RNFL) Thickness between the Normal and Glaucoma Eyes with the Same Vertical Cup Disc Ratio (CDR) using Optical Coherence Tomography (OCT)

Background: Glaucoma is a disease that belongs to a group of neurodegenerative diseases, such as impaired visual field and optic neuropathy with progressive damage to the optic nerve and retinal nerve fiber layer (RNFL) which is caused by the loss of ganglion cells and axon of the optic. Changes in the optic nerve and RNFL may occur prior to the abnormalities of the visual field nerves. Currently, the visual field examination should be performed to diagnose glaucoma but with patient-subjective result. Before it is detectable, visual field abnormalities are likely going to lose its ganglion cells by 40%. The purpose of this study was to assess and compare the peripapillary retinal nerve fiber layer (RNFL) between the normal and glaucoma eyes with vertical cup disc ratio (CDR) 0.4 to 0.7 in eye clinic Cipto Mangunkusumo Hospital (RSCM) Kirana. Methods: A total of 40 eyes of normal group and 34 eyes of glaucoma following Humphrey field analyzer examination and Optical Coherence Tomography (OCT) were evaluated. Peripapillary RNFL thickness between normal and glaucoma eyes were analyzed and compared each other. Eyes of glaucoma group then were grouped into early-stage glaucoma, according to the criteria in the initial stages of the examination results of Humphrey field analyzer. Result of peripapillary RNFL thickness was analyzed to get a cut off value. Results: Peripapillary RNFL thickness in the normal group with vertical CDR 0.4 to 0.7 was 111.3±9.8 μm to 118.0±3.0 μm, and glaucoma groups with vertical CDR 0.4 to 0.7 was 105.6±12.6 μm to 113.7±6.1 μm. Retinal nerve fiber layer thickness in normal group compared to glaucoma group in the superior quadrant, inferior, nasal, temporal and average on CDR 0.4 to 0.7 was not statistically significant (p&gt;0.05), except on vertical CDR 0.6 average peripapillary RNFL (p&lt;0.05). Cut off value of peripapillary RNFL in superior quadrant was 164 μm, inferior 169.5 μm, nasal 82.5 μm, temporal 73.5 μm and average 111.8 μm. Conclusion: There was no difference in changes of peripapillary RNFL along with the progression of vertical CDR but clinically, peripapillary RFNL thickness in glaucoma group is thinner than that of normal group with the same vertical CDR except in temporal quadrant. Keywords: Retinal nerve fiber layer (RNFL), cup disc ratio (CDR), optical coherence tomography (OCT)

Effect of form-deprivation myopia on optic nerve head and retinal morphology in guinea pigs

Objective To evaluate the effect of form deprivation myopia on optic nerve head and retinal morphology in guinea pigs using optical coherence tomography (OCT). Methods Twenty guinea pigs aged from 4 to 5 weeks were chosen and randomly divided into the experimental group and control group, with 10 guinea pigs in each group. Form deprivation myopia was established for the right eyes of guinea pigs in experimental group for 4 weeks. The guinea pigs of control group were not intervened. Before and 4 weeks after form deprivation, refraction was measured by retinoscopy after cycloplegia; the axial length was measured by A-scan ultrasound; retinal nerve fiber layer (RNFL) thickness, optic nerve head and retinal morphology of guinea pigs were analyzed using OCT. Results Before form deprivation, there were no statistically significant differences in spherical equivalent, axial length, RNFL thickness, disc edge area, optic disc area, average cup disc ratio, vertical cup disc ratio, cup volume, retinal thickness, or retinal volume between the experimental group and control group of guinea pig (P>0.05). After 4 weeks of form deprivation, RNFL thickness of (64.9±17.7) μm in guinea pigs in experimental group was thinner compared to (97.9±25.1) μm in control group (t=-2.845, P=0.015). Retinal thickness of (142.7±3.4) μm in guinea pigs in experimental group was thicker compared to (138.4±3.5) μm in control group (t=2.338, P=0.038). There were no significant differences in disc edge area, optic disc area, average cup disc ratio, vertical cup disc ratio, cup volume or retinal volume between groups (P>0.05). There were statistically significant differences in spherical equivalent, axial length, RNFL thickness, vertical cup to disc ratio cup volume, and retinal thickness between after and before form deprivation in the right eye of guinea pigs in the experimental groups (t=46.001, -50.119, 5.385, 3.447, -2.814, -8.911; P 0.05). Conclusion Form deprivation myopia has an effect on RNFL and retinal thickness. Key words: Myopia/complications; Optic disk/physiopathology; Retina/physiopathology; Animal experimentation

The Arclight Ophthalmoscope: A Reliable Low-Cost Alternative to the Standard Direct Ophthalmoscope.

Background. The Arclight ophthalmoscope is a low-cost alternative to standard direct ophthalmoscopes. This study compared the Arclight ophthalmoscope with the Heine K180 direct ophthalmoscope to evaluate its reliability in assessing the vertical cup disc ratio (VCDR) and its ease of use (EOU). Methods. Eight medical students used both the Arclight and the Heine ophthalmoscopes to examine the optic disc in 9 subjects. An EOU score was provided after every examination (a higher score indicating that the ophthalmoscope is easier to use). A consultant ophthalmologist provided the reference standard VCDR. Results. 288 examinations were performed. The number of examinations that yielded an estimation of the VCDR was significantly higher for the Arclight ophthalmoscope (125/144, 85%) compared to the Heine ophthalmoscope (88/144, 61%) (p < 0.001). The mean difference from the reference standard VCDR was similar for both instruments, with a mean of −0.078 (95% CI: −0.10 to −0.056) for the Arclight and −0.072 (95% CI: −0.097 to −0.046) for Heine (p = 0.69). The overall EOU score was significantly higher for the Arclight ophthalmoscope (p < 0.001). Conclusion. The Arclight ophthalmoscope performs as well as, and is easier to use than, a standard direct ophthalmoscope, suggesting it is a reliable, low-cost alternative.

A Comparison of Optic Nerve Head Topographic Measurements by Stratus OCT in Patients With Macrodiscs and Normal-sized Healthy Discs

To evaluate and compare optic nerve head parameters and retinal nerve fiber layer (RNFL) thickness between large discs and normal-sized vital discs using Stratus optical coherence tomography (OCT). A total of 293 healthy eyes (145 with macrodisc and 148 with normal-sized disc) were enrolled in the study. After a complete ophthalmic evaluation, measurement of optic nerve head parameters and RNFL thickness using OCT was performed in all subjects. Optic disc areas larger than 2.80 mm were accepted as macrodiscs. All OCT parameters were compared between normal-sized discs and macrodiscs. Participants' mean age was 46.5±10.6 years (range, 13 to 74 y). Average optic disc areas were 2.19±0.29 and 3.02±0.29 mm in the normal and the macrodisc groups, respectively. The optic disc area (P<0.0001), the cup area (P<0.0001), the horizontal cup disc ratio (P<0.0001), the vertical cup disc ratio (P<0.0001), and the cup disc area ratio (P<0.0001) were found to be significantly different in the macrodisc group and the control group. Rim areas (P=0.57) and RNFL thicknesses (inferior, superior, and mean) were found to be similar in both groups (P=0.75, 0.65, 0.85, respectively). A macrodisc may have a macrocup and should not be misdiagnosed as glaucoma. The present study showed that macrodiscs are identical to normal-sized discs in terms of rim area and RNFL thickness. We suggest that these 2 OCT parameters can help to differentiate a healthy macrodisc from a glaucomatous optic disc.

The relationship between vertical cup-disc ratio and body mass index in Port Harcourt, Nigeria

Glaucoma is the leading cause of irreversible blindness in the world and risk factors to developing glaucoma must be determined early to prevent blindness from the disease. To determine the relationship between vertical cup disc ratio (VCDR) and body mass index (BMI) in a population screened for glaucoma in Port Harcourt, Nigeria. This study was part of a one-day screening exercise for glaucoma at the University of Port Harcourt. Demographic data included age, sex, race and occupation. Height was measured with a wall-mounted tape and weight with a bathroom scale. Intraocular pressure was measured with Perkins applanation tonometer and funduscopy was with direct ophthalmoscope. BMI was calculated as weight in kilograms divided by the square of height in meters (Weight/Height2). A total of 491 subjects were screened; consisting of 230 males (46.8%) and 261 females (53.2%). The mean age was 35±13.29 years. About 28%(n=141) of the participants were overweight while 17.7%(n=87) were obese. The mean BMI was 25.39 ± 4.82 kg/m 2 and the mean VCDR for both eyes was 0.38±0.13mmHgratios have no units. Most participants (n=864; 89.4%) had normal VCDR. Only 102 (10.6%) had cupped discs. There was no statistically significant relationship between BMI and VCDR (P= 0.947; R2 = 0.01). Obesity was not associated with a larger VCDR.

Prospective study on retinal nerve fibre layer changes after an acute episode of phacomorphic angle closure

To investigate the retinal nerve fibre layer (RNFL) changes after an acute attack of phacomorphic angle closure. This prospective study involved ten cases of phacomorphic angle closure that underwent cataract extraction and intraocular lens insertion after intraocular pressure lowering. Apart from visual acuity and intraocular pressure (IOP), RNFL thickness and vertical cup disc ratio (VCDR) were measured by optical coherence tomography (OCT) at 3–9 months post attack. Humphrey visual field assessment was performed at 9 months post attack. All cases had mean phacomorphic duration of <5 days. Postoperatively, best correct Snellen visual acuity was 0.4 ± 0.2 and IOP at 9 months was 11.0 ± 3.1 mmHg. There was no difference in VCDR and RNFL between the attack and contralateral eye at 3 months post attack (both p = 0.4). At 9 months post attack, there was significant thinning in the average (p = 0.01), superior (p = 0.01), and inferior (p = 0.006) RNFL. There was no significant difference in the pattern standard deviation (PSD) between the two eyes on the Humphrey visual field nor was there any correlation between PSD severity and RNFL thinning (all p > 0.2. Patients with <5 days duration of phacomorphic angle closure are likely to have reasonable postoperative vision. An acute episode of phacomorphic angle closure can trigger an accelerated RNFL thinning despite normal IOP and open angles, most noticeable in the superior and inferior quadrants, occurring between 3 and 9 months post attack. Glaucomatous optic neuropathy in the attack eye was evident by OCT but not by visual field assessment at the same time interval.

Population and High-Risk Group Screening for Glaucoma: The Los Angeles Latino Eye Study

To evaluate the ability of various screening tests, both individually and in combination, to detect glaucoma in the general Latino population and high-risk subgroups. The Los Angeles Latino Eye Study is a population-based study of eye disease in Latinos 40 years of age and older. Participants (n = 6082) underwent Humphrey visual field testing (HVF), frequency doubling technology (FDT) perimetry, measurement of intraocular pressure (IOP) and central corneal thickness (CCT), and independent assessment of optic nerve vertical cup disc (C/D) ratio. Screening parameters were evaluated for three definitions of glaucoma based on optic disc, visual field, and a combination of both. Analyses were also conducted for high-risk subgroups (family history of glaucoma, diabetes mellitus, and age ≥65 years). Sensitivity, specificity, and receiver operating characteristic curves were calculated for those continuous parameters independently associated with glaucoma. Classification and regression tree (CART) analysis was used to develop a multivariate algorithm for glaucoma screening. Preset cutoffs for screening parameters yielded a generally poor balance of sensitivity and specificity (sensitivity/specificity for IOP ≥21 mm Hg and C/D ≥0.8 was 0.24/0.97 and 0.60/0.98, respectively). Assessment of high-risk subgroups did not improve the sensitivity/specificity of individual screening parameters. A CART analysis using multiple screening parameters-C/D, HVF, and IOP-substantially improved the balance of sensitivity and specificity (sensitivity/specificity 0.92/0.92). No single screening parameter is useful for glaucoma screening. However, a combination of vertical C/D ratio, HVF, and IOP provides the best balance of sensitivity/specificity and is likely to provide the highest yield in glaucoma screening programs.

Comparing strategies to fine-map the association of common SNPs at chromosome 9p21 with type 2 diabetes and myocardial infarction

Noncoding variants at human chromosome 9p21 near CDKN2A and CDKN2B are associated with type 2 diabetes, myocardial infarction, aneurysm, vertical cup disc ratio and at least five cancers. Here we compare approaches to more comprehensively assess genetic variation in the region. We carried out targeted sequencing at high coverage in 47 individuals and compared the results to pilot data from the 1000 Genomes Project. We imputed variants into type 2 diabetes and myocardial infarction cohorts directly from targeted sequencing, from a genotyped reference panel derived from sequencing and from 1000 Genomes Project low-coverage data. Polymorphisms with frequency >5% were captured well by all strategies. Imputation of intermediate-frequency polymorphisms required a higher density of tag SNPs in disease samples than is available on first-generation genome-wide association study (GWAS) arrays. Our association analyses identified more comprehensive sets of variants showing equivalent statistical association with type 2 diabetes or myocardial infarction, but did not identify stronger associations than the original GWAS signals.