Vertical Cup-disc Ratio Research Articles

A Genetic Epidemiologic Study of Candidate Genes Involved in the Optic Nerve Head Morphology

The size of the optic nerve head, referred to as disc area (DA), and the vertical cup-disc ratio (VCDR), are clinically relevant parameters for glaucomatous optic neuropathy. Although these measures have a high heritability, little is known about the underlying genes. Previously, the genes SALL1 and SIX1 were found to be genome-wide significantly associated with DA and VCDR. The purpose of the present study was to investigate whether genes encoding protein known to interact with protein encoded by SALL1 and SIX1 are also associated with either DA or VCDR. A total of 38 candidate genes were chosen covering all known proteins interacting with SALL1 and SIX1. These were initially studied in the Rotterdam Study (RS)-I, including 5312 Caucasian subjects characterized for DA and VCDR. Positive findings were further investigated in two independent cohorts (RS-II and RS-III) and finally replicated in a fourth population (ERF). Bonferroni correction was applied to the meta-analyses. Three loci were found to be associated with DA. The only locus significant after correcting for multiple testing is located on chromosome 11p13. Three single nucleotide polymorphisms (SNPs) in ELP4, a gene which neighbors and plays a crucial role in the expression of PAX6, show association in meta-analysis of the four cohorts yielding P values of respectively 4.79 × 10(-6), 3.92 × 10(-6), and 4.88 × 10(-6) which is below the threshold dictated by the most conservative Bonferroni correction (P = 5.2 × 10(-6)). This study suggests that the ELP4-PAX6 region plays a role in the DA. Further research to confirm this finding is needed.

Long-term intraocular pressure fluctuation of primary angle closure disease following laser peripheral iridotomy/iridoplasty.

Many studies indicated that short-term and long-term intraocular pressure (IOP) fluctuations in primary open angle glaucoma patients might lead to glaucomatous progression. However, seldom study has evaluated the long-term fluctuation of IOP in primary chronic angle closure diseases. The objective of this study was to investigate the long-term IOP fluctuation of primary angle closure diseases and its associations following laser peripheral iridotomy (LPI) with or without laser peripheral iridoplasty. A total of 158 patients with primary angle closure suspect (PACS, n = 21), primary angle closure (PAC, n = 81) and primary angle closure glaucoma (PACG, n = 55) had been treated by LPI with or without laser peripheral iridoplasty and followed up for more than 12 months. IOP was measured with Goldman applanation tonometer. Multivariate linear regression with generalized estimating equation (GEE) regression models was used to evaluate the association of long-term IOP fluctuation (maximum IOP minus minimum IOP) with gender, age, baseline IOP, baseline peripheral anterior synechia (PAS), baseline vertical cup/disc ratio (VCDR), baseline mean deviation (MD), need for IOP-lowering medications. IOP fluctuation during follow-up in PACS, PAC and PACG groups were (4.83 ± 2.90), (5.67 ± 3.35), and (9.40 ± 7.14) mmHg, respectively. IOP fluctuation was strongly correlated with baseline IOP (r = 0.356, P < 0.001), PAS (r = 0.374, P < 0.001). IOP fluctuation was higher in patients with higher baseline IOP (0.18 mmHg per unit increase, 95%CI: 0.05 - 0.31 mmHg). Long-term IOP fluctuation in PACG group was larger than that in PACS or PAC group. Eyes with higher baseline IOP were observed to have larger long-term IOP fluctuation.

Optic Disc Dimensions and Cup-Disc Ratios among Healthy South Indians: The Chennai Glaucoma Study

Purpose: To present optic disc and cup dimensions, cup-disc ratios (CDRs) and asymmetry among healthy South Indians, and their associations with ocular and systemic variables.Methods: A total of 623 healthy phakic participants of the Chennai Glaucoma Study underwent complete eye examinations including optic disc stereo-photography. Planimetry was performed under stereo-viewing conditions. The morphological type of cupping (no cups, steep cups, partly sloping and fully sloping cups) was identified based on a modification of the classification by Jonas et al. The associations of planimetric measures (optic disc area, cup area and vertical cup-disc ratio [VCDR]) with age, gender, height, intraocular pressure, refraction, astigmatism, axial length and corneal thickness as explanatory variables were examined. The associations of asymmetries in the above planimetric measures with age, gender and asymmetries of the above explanatory variables were examined.Results: Mean optic disc and cup areas were 2.82 ± 0.52 mm2 and 0.53 ± 0.39 mm2. Mean CDR was 0.36 ± 0.18. Men had larger discs (P = 0.03). Cup area and VCDR revealed significant associations with disc area (P <0.0001) and type of cupping (P < 0.0001). Mean disc and cup area asymmetries were 0.19 ± 0.16 mm2 and 0.15 ± 0.15 mm2. Mean VCDR asymmetry was 0.07 ± 0.08 mm2. Cup area and VCDR asymmetries showed significant associations with disc area asymmetry (P < 0.0001, both) and asymmetry in the presence or absence of physiological cupping, i.e. subjects with physiological cupping in one eye and no cupping in the other (P < 0.0001, both).Conclusions: We present normative optic disc, cup and VCDR measures and asymmetries among healthy South Indians. We demonstrated the dependence of VCDR on the morphological type of cupping.

Heidelberg Retina Tomograph (HRT3) in Population-based Epidemiology: Normative Values and Criteria for Glaucomatous Optic Neuropathy

Purpose: To establish normative values for Heidelberg Retina Tomograph (HRT3) variables and to develop HRT3-based criteria for glaucomatous optic neuropathy for epidemiological research in a white population.Methods: Consecutive participants in the Rotterdam Study were examined with HRT and simultaneous stereoscopic fundus photography (ImageNet) in addition to other ophthalmic examinations including intraocular pressure (IOP) measurements and perimetry. Normative values for all HRT3 variables were determined in participants who met all the following criteria: no glaucomatous visual field loss (GVFL), an IOP of 21mmHg or less, no IOP lowering treatment, and a negative family history of glaucoma. Sensitivity was determined in participants with glaucomatous visual field loss at a fixed high specificity of 97.5% − a value commonly used in population-based epidemiology.Results: A total of 2516 participants were included in this study of whom 66 had glaucomatous visual field loss in at least one eye and 1680 fulfilled the criteria for contributing to the normative values. The HRT3 linear cup-disc ratio (LCDR) variable, adjusted for disc area, showed the highest sensitivity, 35%, at the required specificity of 97.5%. The 97.5th percentile of the LCDR was 0.67 for small discs (up to 1.5mm2), 0.73 for medium-sized discs and 0.79 for large discs (above 2.0mm2). The HRT3 Glaucoma Probability Score and previously published linear discriminant functions showed a lower sensitivity than LCDR at this specificity.Conclusions: At the high specificity of 97.5% as is commonly used in population-based epidemiology, the sensitivity of the HRT3 is low − albeit not lower than that of the vertical cup-disc ratio as assessed with simultaneous stereoscopic fundus photography and analyzed with the ImageNet software. The LCDR variable, stratified for disc area, seems to be the most suitable variable to develop criteria for glaucomatous optic neuropathy for epidemiological purposes.

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.

Correlation of Frequency-doubling Perimetry With Retinal Nerve Fiber Layer Thickness and Optic Disc Size in Ocular Hypertensives and Glaucoma Suspects

To determine the structure-function correlation using frequency-doubling technology (FDT) perimetry and optical coherence tomography (OCT) in glaucoma suspects, and analyze their relationship to optic disc size. Sixty eyes of 60 ocular hypertensive patients (OHT) and 54 eyes of 54 subjects with optic disc features suspicious of glaucoma (disc suspects) with normal visual fields on Standard Achromatic Perimetry were recruited. All subjects underwent FDT perimetry using the N-30 program, and the mean deviation (FDT-MD) and FDT-pattern SD were computed. Average and inferior retinal nerve fiber layer (RNFL) thickness and disc area were measured on Stratus OCT. Pearson correlation coefficient was calculated among all the measurements. In disc suspects, FDT-MD correlated significantly with RNFL thickness measurements (P<0.001; P=0.003) and disc area (P<0.001). There was no correlation with the vertical cup-disc area ratio (VCDR) and FDT indices. In OHT, FDT-MD correlated significantly with average RNFL thickness (P=0.038), and there was a significant negative correlation between FDT-MD and the VCDR (0.042). The FDT-pattern SD negatively correlated with RNFL thickness measurements (P=0.008; P=0.03). The disc area correlated significantly with the average and inferior average RNFL thickness measurements in both groups of patients (P=0.029 and P=0.007; P=0.013 and P=0.013, respectively). In OHT, optic discs with larger VCDR and thinner RNFL had lower FDT-MD values. In disc suspects, smaller-sized discs had thinner RNFL and lower values of FDT-MD. FDT perimetry and OCT seem to be useful adjuncts to detect these eyes, which might warrant close follow-up to eventually detect glaucoma by Standard Achromatic Perimetry.

Mid-Term Results of Filtering Surgery in Corticosteroid-Induced Glaucoma Patients

Aim: To analyze the mid-term effect of filtering surgery in patients with corticosteroid-induced glaucoma (CIG). Methods: This case-series study consisted of 20 eyes of 15 corticosteroid-induced glaucoma patients who received trabeculectomy or non-penetrating trabecular surgery (NPTS) from March 2005 to March 2008. Both preoperative and postoperative intraocular pressure (IOP), cup -disk ratio, Humphrey visual fields, number of glaucoma medications were recorded. Characteristics of postoperative blebs were analyzed with Ultrasound biomicroscope (UBM), and slitlamp. Bleb grading and Ultrasound biomicroscope were performed on all glaucoma surgery eyes at a single final time point. Results: 14 eyes were performed trabeculectomy, 6 eyes were performed NPTS. Mean IOP before and after trabeculectomy were 30.5±13.1 and 11.4±3.8 mmHg (p<0.01), respectively. Mean IOP before and after NPTS were 20.3±4.7 and 12.2±3.1 mmHg (p<0.01), respectively. The mean vertical cup-disk ratio (VCDR) was 0.54 before surgery compared with 0.55 just after surgery. No significant changes were found in visual fields before and after surgery (P=0.06). According to the outcome of final IOP, success rate was 100%. Based on slit-lamp and Ultrasound biomicroscope evaluation of the bleb, 90% of blebs were functional and 10% were non-functional. Conclusions: The mid-term glaucoma management in CIG patients undergoing surgery indicated a successful outcome in final IOP and fairly good prognosis for visual function, without antiglaucoma medication.

Common genetic variants associated with open-angle glaucoma

Open-angle glaucoma (glaucoma) is a major eye disorder characterized by optic disc pathology. Recent genome-wide association studies identified new loci associated with clinically relevant optic disc parameters, such as the optic disc area and vertical cup-disc ratio (VCDR). We examined to what extent these loci are involved in glaucoma. The loci studied include ATOH7, CDC7/TGFBR3 and SALL1 for optic disc area, and CDKN2B, SIX1, SCYL1/LTBP3, CHEK2, ATOH7 and DCLK1 for VCDR. We performed a meta-analysis using data from six independent studies including: the Rotterdam Study (n= 5736), Genetic Research in Isolated Populations combined with Erasmus Rucphen Family study (n= 1750), Amsterdam Glaucoma Study (n= 296) and cohorts from Erlangen and Tübingen (n= 1363), Southampton (n= 702) and deCODE (n= 36 151) resulting in a total of 3161 glaucoma cases and 42 837 controls. Of the eight loci, we found significant evidence (P= 1.41 × 10(-8)) for the association of CDKN2B with glaucoma [odds ratio (OR) for those homozygous for the risk allele: 0.76; 95% confidence interval (CI): 0.70-0.84], for the role of ATOH7 (OR: 1.28; 95% CI: 1.12-1.47) and for SIX1 (OR: 1.20; 95% CI: 1.10-1.31) when adjusting for the number of tested loci. Furthermore, there was a borderline significant association of CDC7/TGFBR3 and SALL1 (both P= 0.04) with glaucoma. In conclusion, we found consistent evidence for three common variants (CDKN2B, ATOH7 and SIX1) significantly associated with glaucoma. These findings may shed new light on the pathophysiological protein pathways leading to glaucoma, and point to pathways involved in the growth and development of the optic nerve.

The 97.5th and 99.5th Percentile of Vertical Cup Disc Ratio in the United States

The International Society of Geographical and Epidemiological Ophthalmology (ISGEO) suggests a case definition for the prevalence studies of glaucoma based on the 97.5th and 99.5th percentile of vertical optic cup distribution among the evaluated population. Although multiple studies evaluating the prevalence of glaucoma have been undertaken in the last 20 years, case definitions have varied, and data on the underlying population distribution are sparse. This study evaluates the population distribution of 97.5th and 99.5th percentile of vertical cup disc ratio (VCDR) and VCDR asymmetry (VCDRA) in the US population and its association with demographic characteristics, self-reported glaucoma, and visual field. The National Health and Nutrition Examination Survey (NHANES) is a nationally representative sample of the US population, which during the years 2005 to 2008 collected frequency doubling technology screening fields and digital fundus photography. Accounting for the complex design of the NHANES population, estimates of the 97.5th and 99.5th percentile of VCDR and VCDRA were calculated, and national estimates of glaucoma prevalence were generated. Associations between disc characteristics, demographic variables, and self-reported glaucoma were explored. Approximately 2.11% (95% confidence interval, 1.55 to 2.67) of the US population older than 40 years has glaucoma based on ISGEO criteria. A much larger 5.13% (95% confidence interval, 4.43 to 5.85) of the US population older than 40 years self-reports having glaucoma. Based on the estimates from NHANES, 6.89% of the population has a VCDR or VCDRA >97.5th percentile in either eye or OU. For the at-risk population with VCDR/VCDRA above the 97.5th percentile, <20% reported having glaucoma, whereas for those at the 99.5th percentile, <50% reported having glaucoma. The prevalence of glaucoma from NHANES based on ISGEO criteria produces similar population estimated to other population-based studies. Self-reported glaucoma is ∼2.4 times more common than what the prevalence estimates suggest.

Diagnostic Assessment of Normal and Pale Optic Nerve Heads by Confocal Scanning Laser Ophthalmoscope and Stereophotography

To evaluate the diagnostic assessment of optic nerve heads (ONH) by stereophotography (SP) and Heidelberg retina tomograph (HRT) in patients with retinitis pigmentosa (RP). This study involved 53 consecutive patients with RP and 24 controls who underwent ONH examination by SP and HRT. On the basis of the appearance at SP, RP ONH were divided in normal-colored (24/53) and pale (29/53). The measurements of vertical ONH diameter and vertical cup/disc ratio (VCDR) by SP and HRT were compared between the groups by means of t test and Bland-Altman plots. Diagnosis, ONH pallor and size, HRT image quality (image standard deviation, SD) were also inspected as sources of differences in the results by means of a multivariate analysis. Vertical diameter measurements were similar using SP and HRT, respectively (1.93±0.50 and 1.80±0.62 for normal-colored ONH, P=0.43; 2.02±0.65 and 1.90±0.40 for pale ONH, P=0.27; and 1.98±0.55 and 1.84±0.52 for controls, P=0.33). In normal-colored ONH, VCDR was 0.30±0.11 at SP and 0.31±0.21 at HRT (P=0.90); in controls, it was 0.29±0.13 at SP and 0.30±0.18 at HRT (P=0.77). In the group with pale ONH, VCDR was 0.34±0.14 at SP and 0.53±0.24 at HRT (P<0.001). HRT image quality was the only parameter which influenced the difference in VCDR estimates between SP and HRT (P=0.02). In patients with pale ONH, this difference was significantly higher, when images of acceptable quality were used for analysis (0.36±0.15 vs. 0.15±0.21 for images with good quality or better, P=0.03). In ONH diseases other than glaucoma, HRT may give misleading information when images of acceptable quality are considered for analysis. We therefore recommend the use of images with good quality or better (SD ≤30 μm) in these cases.

Optic disc topography in normal Indian eyes using spectral domain optical coherence tomography

Purpose:The aim was to study optic nerve head (ONH) parameters in normal Indian eyes using spectral domain optical coherence tomography (OCT)/scanning laser ophthamoscope (SLO).Materials and Methods:One hundred and fifty-seven eyes of 157 normal subjects of various age groups underwent ONH imaging with spectral OCT/SLO and the parameters obtained were correlated with disc size. The effect of age, gender, and refractive error on various ONH parameters were also studied.Results:The mean optic disc area was 3.36 ± 0.64 mm2 (range, 2.13–5.08 mm2), mean rim area was 2.49 ± 0.58 mm2 (range, 1.20–3.62 mm2), and mean cup area was 1.10 ± 0.75 mm2 (range, 0–3.07 mm2). The disc area showed significant positive correlation with the rim area, cup area, horizontal cup disc ratio, vertical cup disc ratio, cup disc area ratio, mean cup depth, and maximum cup depth (P < 0.001). Neither gender nor refractive error showed any significant difference in various ONH parameters. ONH parameters did not show significant change with age except for rim area which declined with the advancing age (r = –0.25, P < 0.001).Conclusions:The quantitative measurement of ONH topography obtained with this study provides a normative database for an Indian population with spectral OCT/SLO. As optic disc area influences ONH topography, disc size should to be considered when evaluating optic disc for progressive optic neuropathies such as glaucoma.

Genetic architecture of open angle glaucoma and related determinants

BackgroundAlthough the vertical cup-disc ratio (VCDR) and intraocular pressure (IOP) are important determinants of open angle glaucoma (OAG), it is unclear to what extent the genetic origin of these traits...

Comparison of two ophthalmoscopes for direct ophthalmoscopy

To measure the ease of use and performance of the Optyse lens-free ophthalmoscope compared with the standard Keeler pocket ophthalmoscope, and to assess its suitability as an inexpensive ophthalmoscope for medical students. Randomized cross-over study. Twenty second-year medical students, 10 as ophthalmoscopists ('observers') and 10 as 'patients'. Students used both ophthalmoscopes to examine the optic disc in each eye of 10 'patients'. They were randomized as to the order in which they were used. A Consultant ophthalmologist was used as the gold standard. Main outcome measures were accuracy in estimating vertical cup:disc ratio (VCDR), ease of use (EOU) for each examination, and overall ease of use (OEOU). Of 400 attempted eye examinations, sufficient visualization was achieved in 220 cases to allow a VCDR estimation: 107/200 VCDR estimates with the Optyse and 113/200 with the Keeler. Accuracy of VCDR estimates was better with the Optyse by the equivalent of 0.05 VCDR (P = 0.002). There was no significant difference in EOU or OEOU between the two ophthalmoscopes. EOU for 400 examinations: median (IQR) of 6 (3-8) for Optyse versus 6 (3-8) for Keeler (P = 0.648). OEOU for 20 scores: median (IQR) of 6.5 (2-9) for Optyse versus 5.5 (3-8) for Keeler (P = 0.21). Medical students found the Optyse and Keeler pocket ophthalmoscopes to be of similar ease of use and performed slightly better with the Optyse when estimating VCDR. The lens-free Optyse ophthalmoscope is a reasonable alternative to the standard Keeler pocket ophthalmoscope.

Retrospective case series on the long-term visual and intraocular pressure outcomes of phacomorphic glaucoma

To analyse the long-term visual acuity (VA) and intraocular pressure (IOP) outcomes in phacomorphic glaucoma. A retrospective analysis of 100 consecutive, acute phacomorphic glaucoma cases from January 2000 to April 2009 was conducted at The Caritas Medical Centre in Hong Kong. All cases underwent cataract extraction after IOP control with medication and/or laser. During a 3.1±2.6-year follow-up, the mean visual improvement was 1.1±0.9 LogMAR units with improvements in 81.7% of cases. A shorter duration from symptoms to cataract extraction resulted in greater visual improvement (r(2)=0.1, P=0.001). In all, 80.5% of the cases had IOP≤21 mm Hg without any glaucoma treatment; 19.5% required 1.6±0.7 glaucoma eye drops; and 3.7% required additional laser iridotomy or trabeculectomy for IOP control at 1.8±2.3 years. The vertical cup-disc ratio (VCDR) of the index eye was 0.6±0.3. Gonioscopy revealed an averaged Shaffer grading of 3.0±1.0 and 99±90 degrees of peripheral anterior synechiae (PAS). The Humphrey automated perimetry mean deviation was 5.2±2.7 and the pattern standard deviation was -15.9±10. Over 80% of phacomorphic patients had long-term visual improvements and normalization of IOP after cataract extraction. A shorter attack seemed to offer better VA. Post-operatively, most have open angles with some degree of PAS formation, and glaucomatous optic neuropathy is evident from enlarged VCDRs and visual field defects. At least 2 years of follow-up is useful to detect a 20% glaucoma progression possibly requiring additional glaucoma treatments.

Simulated cup/disc ratio: a tool for ophthalmologists

To evaluate and compare the observers' ability to measure simulations of cup/disc ratios (CDR) as concentric and non-concentric circles. In a prospective, random, and masked setting, 43 images representing the CDR spectrum from 0.2 to 0.9 for vertical and horizontal CDR measurements were developed and presented on a computer screen to 171 participants. There were satisfactory agreements according to the kappa coefficient (0.755 and 0.730 for horizontal and vertical cup disc ratios, respectively) and Lin's concordance correlation (R=0.88 and R=0.86 for horizontal and vertical measurements, respectively). However, very poor agreement was found for intermediate CDR values. The worst agreement occurred when the CDR was between 0.4 and 0.6 for both the horizontal and vertical values. The kappa coefficient was 0.37 and 0.39 for 0.4 CDR (horizontal and vertical, respectively), 0.39 and 0.38 for 0.5 CDR (horizontal and vertical, respectively) and 0.45 and 0.41 for 0.6 CDR (horizontal and vertical, respectively). Despite a good general agreement between the gold standard and the participants' responses, the absolute agreement for intermediate CDR values was very poor for both horizontal and vertical values.

A Genome-Wide Association Study of Optic Disc Parameters

The optic nerve head is involved in many ophthalmic disorders, including common diseases such as myopia and open-angle glaucoma. Two of the most important parameters are the size of the optic disc area and the vertical cup-disc ratio (VCDR). Both are highly heritable but genetically largely undetermined. We performed a meta-analysis of genome-wide association (GWA) data to identify genetic variants associated with optic disc area and VCDR. The gene discovery included 7,360 unrelated individuals from the population-based Rotterdam Study I and Rotterdam Study II cohorts. These cohorts revealed two genome-wide significant loci for optic disc area, rs1192415 on chromosome 1p22 (p = 6.72×10−19) within 117 kb of the CDC7 gene and rs1900004 on chromosome 10q21.3-q22.1 (p = 2.67×10−33) within 10 kb of the ATOH7 gene. They revealed two genome-wide significant loci for VCDR, rs1063192 on chromosome 9p21 (p = 6.15×10−11) in the CDKN2B gene and rs10483727 on chromosome 14q22.3-q23 (p = 2.93×10−10) within 40 kbp of the SIX1 gene. Findings were replicated in two independent Dutch cohorts (Rotterdam Study III and Erasmus Rucphen Family study; N = 3,612), and the TwinsUK cohort (N = 843). Meta-analysis with the replication cohorts confirmed the four loci and revealed a third locus at 16q12.1 associated with optic disc area, and four other loci at 11q13, 13q13, 17q23 (borderline significant), and 22q12.1 for VCDR. ATOH7 was also associated with VCDR independent of optic disc area. Three of the loci were marginally associated with open-angle glaucoma. The protein pathways in which the loci of optic disc area are involved overlap with those identified for VCDR, suggesting a common genetic origin.

African Descent and Glaucoma Evaluation Study (ADAGES)

To investigate differences in visual function between the healthy eyes of people of African (AD) and European descent (ED). Visual function was assessed in 393 AD and 367 ED participants selected from the African Descent and Glaucoma Evaluation Study and the Diagnostic Innovations in Glaucoma Study. Participants had normal appearance of the optic disc and intraocular pressure of less than 22 mm Hg. Each participant had 2 reliable 24-2 standard automated perimetry tests, and most had short-wavelength automated perimetry and frequency-doubling technology tests. The generalized estimating equation was used to adjust for intereye correlations. Results were adjusted for age, vertical cup-disc ratio, disc size, central corneal thickness, and presence of high blood pressure. The AD participants were younger (mean [SD] age, 46.2 [13.2] years) than the ED participants (age, 49.5 [16.6] years) (P = .003). The AD participants had worse mean deviation and pattern standard deviation and more points triggered as abnormal on the total and pattern deviation plots compared with ED participants on all tests (P < .05). A larger percentage of AD participants had confirmed abnormal glaucoma hemifield test results on standard automated perimetry only. People of AD have significantly worse performance than people of ED on all tests of visual function. Additional research using longitudinal data is needed to determine the cause of these small but significant ancestry differences in visual function.

Pattern electroretinogram optimized for glaucoma screening (PERGLA) and retinal nerve fiber thickness in suspected glaucoma and ocular hypertension

The purpose of this study is to evaluate pattern electroretinogram optimized for glaucoma screening (PERGLA) and retinal nerve fiber layer (RNFL) at spectral optical coherence tomography (OCT) in eyes with suspected glaucoma (GS) and in eyes with ocular hypertension (OHT). This is a cross-sectional, observational study. Twenty-four patients with GS (BCVA 20/20, normal visual field, intraocular pressure, IOP, less than 21 mmHg, and glaucomatous optic neuropathy, GON) and 14 patients with OHT (BCVA 20/20, intraocular pressure 25 mmHg, absence of glaucomatous optic neuropathy and normal visual field) were considered in this study. GON was intended as vertical cup-disk ratio of 0.5 or more; asymmetry of greater than 0.2, disk notching, disk splinter hemorrhages. PERGLA amplitude and phase were measured, while thickness of the RNFL was obtained with spectral OCT. A control group of 50 age-matched healthy patients was added. In the GS group, 16 eyes (66.7%) showed normal average RNFL analysis and normal PERGLA, 3 eyes (12.5%) showed abnormal average RNFL analysis and abnormal PERGLA, 5 eyes (20.8%) presented with normal average RNFL analysis and abnormal PERGLA. In the OHT group, 11 eyes (78.6%) showed an average normal RNFL and normal PERGLA, while 3 eyes (21.4%) presented with an average normal RNFL and abnormal PERGLA. PERGLA is a non-invasive, fast, and fully automatic version of the pattern ERG. In eyes with OHT and in eyes with GS, PERGLA abnormalities in presence of a normal RNFL could suggest an early functional damage of viable retinal ganglion cells.

Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography: A Study on Diagnostic Agreement with Heidelberg Retinal Tomograph

To evaluate and compare the diagnostic agreement and performance for glaucoma detection between a confocal scanning laser ophthalmoscope and a spectral-domain optical coherence tomograph (OCT). Prospective, cross-sectional study. One hundred fifty-five subjects (79 glaucoma and 76 normal subjects). One eye from each individual was selected randomly for optic disc and retinal nerve fiber layer (RNFL) imaging by the Heidelberg Retinal Tomograph (HRT; Heidelberg Engineering, GmbH, Dossenheim, Germany) and the Spectralis OCT (Heidelberg Engineering), respectively. Glaucoma was defined based on the presence of visual field defects with the Humphrey visual field analyzer (Carl Zeiss Meditec, Dublin, CA). The agreement of the categorical classification ("within normal limits," "borderline," and "outside normal limits") at the temporal, superotemporal, superonasal, nasal, inferonasal and inferotemporal sectors of the optic disc were evaluated (kappa statistics). The diagnostic sensitivity and specificity between optic disc and RNFL assessment were compared (McNemar's statistics). Area under the receiver operating characteristic curve (AUC) of OCT RNFL and HRT optic disc parameters were computed after adjustment of age, axial length, and optic disc area. Agreement of categorical classification, AUC of optic disc, and RNFL parameters. The agreement of categorical classification between HRT and Spectralis OCT were fair to moderate (kappa ranged between 0.30 and 0.53) except for global (kappa = 0.63) and inferotemporal (kappa = 0.68) measurements. Defining glaucoma as having "outside normal limits" in the global and/or in >or=1 of the sectoral measurements, the respective sensitivities of Spectralis OCT and HRT were 91.1% and 79.8% (P = 0.012) at a similar level of specificity (97.4% and 94.7%). The AUC of OCT global RNFL thickness (0.978) was greater than those of HRT global rim area (0.905), vertical cup-disc ratio (0.857), rim-disc area ratio (0.897), and multivariate discriminant analysis (0.880-0.925; all with P<or=0.028) after covariates adjustment. The diagnostic classification provided in the HRT and Spectralis OCT analysis report may not agree. At a comparable level of specificity, Spectralis OCT RNFL measurement attained a higher sensitivity than HRT optic disc measurement.

Effect of phacoemulsification on the primary open angle glaucoma control after trabeculectomy: a case‐control study

Abstract Purpose In this retrospective and comparative study, we analyzed the influence of phacoemulsification (PE) on the glaucoma control in case patients (trabeculectomy‐phacoemulsification [CE]) compared with the control that underwent trabeculectomy (T) alone in eyes with primary open angle glaucoma (POAG). Methods Twenty one patients who underwent PE subsequent to T were identified, and 41 who underwent T alone were matched. Visual acuity (VA), intraocular pressure (IOP), bleb appearance, vertical cup disc ratio (VCDR), visual field (VF), glaucoma medications, iris manipulation and complications were documented. Mean follow up was 12 months. Success was defined when IOP ≤ 21 mmHg with the abscense of glaucoma medication and/or further surgical intervention. Results Patients in CE group had no significant change in IOP from pre‐operative measures to 12 months post‐operative (p=0.001). The mean IOP reduced from 15.3 mm Hg to 14.7 mmHg postoperatively. The control group showed an average IOP reduction of 6 mm Hg in the last visit. In CE group, 19% required 1 or 2 glaucoma medications at one year fellow‐up vs 19.5% in the control group. In CE group 9.5% showed flattening of previously formed bleb in the last visit (P&lt;0.001), 9.7 % ended with flat bleb in the T group. The increase in VCDR for the CE group was statistically significant when compared to the control group (p&lt;0.001). Patients in CE group were more likely to exhibit a change in VF (47.6% versus 7.3% respectively). The study is limited by the small number of cases available. Conclusion Corneal PE in eyes with filtering blebs does not adversely affect long‐term glaucoma control in patients with POAG.