Optic disc morphology on presentation of chronic glaucoma (original) (raw)
The optic disc in glaucoma. I: Classification
British Journal of Ophthalmology, 1976
The pale, cupped disc found in the final stages of glaucomatous disease has been known from the time of Von Graefe (I854). Since then many observers have described changes that occur at the optic disc in chronic, simple glaucoma. There has been particular interest in changes which may occur in the early stages of the disease. Studies of the normal population have shown that while there is a wide diversity in the appearance of the normal optic disc, in a single subject (Armaly, I969; Fishman, I970; Kolker and Hetherington, 1970; Portnoy, 1973) the two discs are remarkably similar (Witsiuk, I966; Kronfeld, 1970; Woodruff, 1970; Portnoy, I973). In contrast, individuals with glaucomatous disease usually show manifest asym- metry of the two optic discs (Fishman, I970; Kolker and Hetherington, 1970). Many criteria have been used to describe the glaucomatous optic disc. Important among these is the ratio of the cup diameter to the diameter of the entire disc (Pickard, I923; Snydacker, I964; Hollows and McGuiness, I967; Armaly, i967, I968; Schwartz, I973; Tomlinson and Phillips, I974). This was initially measured horizontally, but recently measurement of the vertical cup to disc (C/D) ratio has been stressed, after recognition that changes in the optic cup tend initially to affect the vertical diameter (Chandler and Grant, I965; Kronfeld, I967; Kirsch and Anderson, 1973; Weisman, Assif, Phelps, Podos, and Becker, 1973). Stereoscopic examination of the optic disc in early glaucoma reveals signs which help to distinguish the normal from the glaucomatous cup (Anderson, I975; Reed and Spaeth, I974). These signs are evidence for acquired tissue loss and account for the asymmetry previously noted. Tissue loss may appear in a variety of forms: thinning of the neuro- retinal rim, either localized or generalized; depres- sion or steepening of the walls of the cup (the tinted hollow (Reed and Spaeth, 1974) or saucer); Address for reprints: R. A. Hitchings, FRCS, Moorfields Eye Hospital, City Road, London ECIV 2PD 3 to 4 mm. Slides were examined with a stereoscopic viewer. The stereo pairs of the two eyes were directly compared. Special note was made of identifying characteristics suggestive of tissue loss. The following criteria were analysed: copyright.
Key Papers on Optic Disc Evaluation in Glaucoma
Optic nerve diseases, such as the glaucomas, lead to changes in the intrapapillary and parapapillary region of the optic nerve head. These changes can be described by the following variables: size and shape of the optic disk; size, shape, and pallor of the neuroretinal rim; size of the optic cup in relation to the area of the disk; configuration and depth of the optic cup; ratios of cup-to-disk diameter and cup-to-disk area; position of the exit of the central retinal vessel trunk on the lamina cribrosa surface; presence and location of splinter-shaped hemorrhages; occurrence, size, configuration, and location of parapapillary chorioretinal atrophy; diffuse and/or focal decrease of the diameter of the retinal arterioles; and visibility of the retinal nerve fiber layer (RNFL). These variables can be assessed semiquantitively by ophthalmoscopy without applying sophisticated techniques. For the early detection of glaucomatous optic nerve damage in ocular hypertensive eyes before the development of visual field loss, the most important variables are neuroretinal rim shape, optic cup size in relation to optic disk size, diffusely or segmentally decreased visibility of the RNFL, occurrence of localized RNFL defects, and presence of disk hemorrhages. ( Surv Ophthalmol 43 :293-320, 1999. © 1999 by Elsevier Science Inc. All rights reserved.) Key words. cup/disk ratio • neuroretinal rim • optic cup • optic disk • optic disk hemorrhages • optic disk pallor • parapapillary atrophy • peripapillary scleral ring • retinal nerve fiber layer • retinal vessel diameter ABSTRACT Purpose: The major objective of this study was to test the reproducibility of a new method of estimating the amount of optic disc damage in patients with glaucoma.
Clinical measurement and categorization of optic disc in glaucoma patients
Indian Journal of Ophthalmology, 2009
Background: Assessment of optic disc size is an important component of optic nerve head examination. Agreement between different methods of disc size measurements is not very good. Purpose: To assess the agreement between the disc size assessed by Heidelberg retina tomograph (HRT) and stereobiomicroscopy with a 90 diopter (D) lens. To report the clinical (measured by biomicroscopy) disc diameters of small, average and large optic discs categorized by HRT disc areas. Setting and Design: Observational study of subjects examined in the glaucoma clinic of a tertiary eye institute. Materials and Methods: Seventy-five eyes of 75 glaucoma subjects were studied. Disc diameter was measured using stereobiomicroscopy and HRT. The agreement between the two sets of measurements was assessed by intraclass correlation coefficient (ICC). Discs were classified into small (<1.6 mm 2), average (1.6-2.6 mm 2) and large (>2.6 mm 2) depending on cutoffs provided by the manufacturers of HRT. The means (95% CI) of the corresponding vertical disc diameter in these groups were assessed. Statistical Analysis: ICC, Bland and Altman plots. Results: ICC for measurements of clinical and HRT horizontal disc diameter was 0.518 and for vertical disc diameter measurement was 0.487. The mean difference between the clinical and HRT measurements as analyzed by the Bland and Altman plot was 0.17 (95% CI, 0.13-0.47) for horizontal and 0.22 (95% CI, 0.11-0.54) for vertical disc diameter. Of the 75 eyes, 3 eyes had small discs, 54 average and 18 large discs. The mean clinical vertical disc diameter for small discs was 1.55 mm (95% CI, 1.2-1.7), for average discs was 1.91 mm (95% CI, 1.87-1.96) and for large discs was 2.15 mm (95% CI, 2.03-2.27). Conclusion: The agreement between clinical and HRT disc diameter measurements is moderate. Disc diameter measurement on stereobiomicroscopy can be used to categorize discs into small, average and large discs.
Morphometric characteristics of optic disc in patients with myopia and primary open-angle glaucoma
Vojnosanitetski pregled, 2013
Primary open-angle glaucoma is a multifactorial and progressive neuropathy, characterised by the acquired loss of ganglion cells of the retina and their axons. One of the risk factors for primary open-angle glaucoma is myopia over 5 diopters (D). The aim of our work was to investigate two groups of patients with primary open-angle glaucoma and myopia by using confocal scanning laser ophthalmoscopy, and to find out if the size of refractive error influences optic disk morfometric characteristics. Methods. One hundred eyes of one hundred patients with primary open-angle glaucoma and myopia were involved in our study. All the patients were classified into two groups, the first one with myopia < 5 D, and the second one with myopia 5 D. The Heidelberg retina tomograph is a technique we used in our study. We analized morfometric parameters of patients optic discs, with the aim to find a correlation between the parameters in each group separeatly, and also to find differences between the same parameters from both groups. Results. There were significant differences in disc area, cup area, rim area and mean RNFL thickness between the two groups. The size of damage of neuroretinal rim in the group with high myopia was 27%, and in the group with lower myopia 14%. The most frequently damaged segment of neuroretinal rim in the patients with high myopia was nasal segment and in the patients with low myopia infero-temporal one. The least frequently damaged segment of neuroretinal rim in both groups was temporal one. Conclusion. Optic discs of glaucomatous patients with high myopia have bigger diameter, also bigger and more irregularly distributed damaged zone of neuroretinal rim, and also thinner retinal nerve fiber layer compared to glaucomatous patients with lower myopia.
Eye, 2011
Purpose To compare the diagnostic accuracy of the Heidelberg Retina Tomograph's (HRT) Moorfields regression analysis (MRA) and glaucoma probability score (GPS) with that of subjective grading of optic disc photographs performed by ophthalmologists with varying experience of glaucoma and by ophthalmology residents. Methods Digitized disc photographs and HRT images from 97 glaucoma patients with visual field defects and 138 healthy individuals were classified as either within normal limits (WNL), borderline (BL), or outside normal limits (ONL). Sensitivity and specificity were compared for MRA, GPS, and the physicians. Analyses were also made according to disc size and for advanced visual field loss. Results Forty-five physicians participated. When BL results were regarded as normal, sensitivity was significantly higher (Po5%) for both MRA and GPS compared with the average physician, 87%, 79%, and 62%, respectively. Specificity ranged from 86% for MRA to 97% for general ophthalmologists, but the differences were not significant. In eyes with small discs, sensitivity was 75% for MRA, 60% for the average doctor, and 25% for GPS; in eyes with large discs, sensitivity was 100% for both GPS and MRA, but only 68% for physicians. Conclusion Our results suggest that sensitivity of MRA is superior to that of the average physician, but not that of glaucoma experts. MRA correctly classified all eyes with advanced glaucoma and showed the best sensitivity in eyes with small optic discs.
Study of correlation of cup disc ratio with visual field loss in primary open angle glaucoma
Innovative Publication, 2017
Objective: To correlate the cup/disc ratio with visual field defect in primary open angle glaucoma patient using magnified photograph of optic disc and Humphrey field analyzer. Method: Cross sectional study includes 114 eyes of 60 patients suffering from primary open angle glaucoma. All patients were 40 years age having IOP 21 mmHg and gonioscopically open angle of anterior chamber. The things assessed includes IOP, angle of anterior chamber, optic disc and visual field. Results: Total 114 eyes of 60 patients with primary open angle glaucoma included in study. Mean age of patient in our study was 58.7±10.26 year. Out of 60 patients, 31 (51.66%) were male and 29 (48.33%) were female. 12 eyes (10.52%) had IOP in the range of 21-24 mmHg, 52 eyes (45.61%) had IOP in the range of 25-29 mmHg, 48 eyes (42.10%) had IOP in the range of 30-34 while only 2 eyes (1.75%) had IOP > 35 mmHg. Mean IOP of 114 eyes was 27.9±3.23 mmHg. 32 patient (28.07%) had C:D ratio of 0.6 whereas 30 patient (26.31s%) had C:D ratio 0.7. Mean C:D ratio of POAG was 0.64±0.07. Considering other parameter of the optic nerve head it was seen that Bayonetting sign was present in 60 eyes. Meanwhile baring of vessels was seen in 46 eyes. Laminar dot sign, on the other hand was seen in 72 eyes. Beta zone peripapillary atrophy was seen in 78 eyes. Another important parameter of the optic disc is notching. In 53 eyes notching was seen. Out of these, 35 eyes show superior notching, of which 33 eyes (94.3%) correlated with inferior field defects. 18 eyes show inferior notching, and all of them showed superior field defect. Inferior neuroretinal thinning is found in 55 eyes, out of which 50 eyes (90.9%) had correlating visual field defect while 32 eyes (86.5%) with superior neuroretinal thinning correlate visual field defect. Maximum number of eyes show superior zone defect i.e. 54 eyes (47.36%) followed by inferior zone defect in 25 eyes (22.0%). The least common visual field defect in our study is baring of blind spot in 3 eyes (3.0%). Finally, the patients were divided into 2 group depending on their cup disc ratio, and their association with the field defects was evaluated. Group 1-patients with c:d ratio < 0.7;Group 2-patients with c:d ratio 0.7. The pattern defects signifying the localized defects were then compared between the two group. The average pattern defect in group-1 was found to be 6.16 db, while the average pattern deviation in group-2 was 9.62 db. The association of c:d ratio 0.7 with PD was seen to be significant with a p <0.001. Conclusions: This was a cross sectional study done over a period of 1 year to correlate the optic disc changes with the visual field defects by using optic disc evaluation and Humphrey visual field analyzer done. The correlation between cup disc ratio and intra.
Optic Disk Appearances in Primary Open-Angle Glaucoma
Survey of Ophthalmology, 1999
Primary open-angle glaucoma almost certainly develops in a multifactorial manner, with interplay between numerous risk factors affecting the disease. These risk factors, in addition to intraocular pressure, include a number of cardiovascular factors. Some of these factors may determine the appearance of the damaged glaucomatous optic nerve head. Patients with four specific optic disk appearances have been investigated, and differences have been identified in their demographic characteristics, prevalence of certain risk factors, the pattern of visual field damage, and circulatory abnormalities in their retrobulbar vessels. The findings provide evidence of the existence of subgroups of primary open-angle glaucoma with correlations between risk factor and type of optic disk. A reliable method by which the different disk appearances could be distinguished in an objective manner would be clinically valuable, and the scanning laser ophthalmoscope has shown potential promise to achieve this. The results of studies relating to various glaucomatous optic disk appearances are presented and discussed.
Changes in the Optic Disc after Acute Primary Angle Closure
Ophthalmology, 2006
To evaluate the changes in optic disc morphology in the first 4 months after an episode of acute primary angle closure (APAC) using stereoscopic optic disc photography and computer-assisted planimetry. Prospective observational case series. Forty-seven Asian subjects with unilateral APAC who were successfully treated with laser peripheral iridotomy (LPI). Cup-to-disc ratio (CDR) and optic cup and neuroretinal rim areas. Stereoscopic optic disc photographs were taken 2 and 16 weeks after LPI, and the images were analyzed by computer-assisted planimetry. The overall, quadrantic, and 30 degrees sector areas of the optic disc, CDR, and neuroretinal rim area were analyzed by 2 independent masked graders, and the mean of the readings was used to calculate changes in optic disc parameters. The majority of the subjects were female (66%) and Chinese (90%), and the mean age was 67.6+/-11.2 years (range, 40-94). In APAC eyes from week 2 to week 16, the mean CDR increased from 0.56+/-0.05 to 0.59+/-0.03 (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001), and the mean neuroretinal rim area decreased from 1.74+/-0.31 mm2 to 1.59+/-0.27 mm2 (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Quadrantic and sector analysis showed preferential loss of neuroretinal rim area at the superotemporal and inferotemporal areas. There was no significant change in optic disc parameters in the fellow eyes over the study period. This study demonstrated changes in optic disc morphology from week 2 to week 16 after an episode of APAC. The pattern of optic nerve damage demonstrated in our study was comparable with that seen in primary open-angle glaucoma and experimental glaucoma models.
Optometry and Vision Science, 2007
Purpose. To analyze the priority of morphological and functional defects in glaucoma. Methods. Nine-hundred seventy-three eyes of 973 subjects were examined with Heidelberg retinal tomograph (HRT II) and Octopus 311 perimeter (TOP strategy). These included 72 controls (C), 659 early and suspect open angle glaucoma (ESG) with perimetric mean defect (MD) lower than 6 dB, and 242 confirmed moderate and advanced glaucomas (AG) with perimetric MD Ն6 dB. Results. I. (Control group): Age was significantly correlated with mean sensitivity (MS) (r ϭ 0.50, p Ͻ 0.00001) and nasal cup shape measure (r ϭ 0.33, p ϭ 0.005). II. (C and ESG groups): For 95.8% specificity, the best sensitivity was obtained with square root of loss variance (sLV) (ROC area ϭ 69.7%, sensitivity ϭ 33.7%) and maximum contour elevation (ROC area ϭ 69.6%, sensitivity ϭ 29.0%). Maximum contour elevation and sLV coincided in diagnosis in 12.4% of cases. An equation using 64 HRT II indices predicted MS with a standard error of estimate (SEE) of 1.87 dB (r ϭ 0.67, p Ͻ 0.00001) and MD (SEE ϭ 1.88 dB, r ϭ 0.47, p Ͻ 0.00001). III. (All cases): RB discriminant function value was the best HRT II index to estimate MS values (SEE ϭ 5.4 dB, r ϭ 0.52, p Ͻ 0.0001), MD (SEE ϭ 5.2 dB, r ϭ 0.50, p Ͻ 0.0001), sLV (SEE ϭ 1.9 dB, r ϭ 0.41, p Ͻ 0.0001) and Number of Pathological Points (NPP; SEE ϭ 21.3 dB, r ϭ 0.49, p Ͻ 0.0001). Sector correlation of the optic nerve and visual field was high (maximum r ϭ 0.66) in cases with superior visual field defects and low in the rest of cases. More than 95% of cases with established glaucoma had abnormal sLV, but Ͻ60% had abnormal optic disc indices. Discussion. Perimetry reveals age-related defects slightly more than HRT II. HRT II indices correlated better with MS than with MD, probably because none of them was age corrected. Good correlation between anatomical and functional data in C and ESG, and sensitivity results indicated small differences in early development between both methods. Perimetry identifies defects more clearly than structural measures in established glaucoma.