The cumulative normalised rim/disc area ratio curve

BACKGROUND: The assessment of the cup of the optic disc depends, among other criteria, on the disc area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, while on the other hand a large cup in a large optic disc can be normal. Therefore, a cumulative normalised rim/disc area ratio curve could help to distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate normalised rim/disc area ratio curve. METHODS: Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc area-adjusted normalised rim/disc area ratio in sectors of 10 degrees. The 95th, 90th and 50th percentiles of each of the 36 sectors were displayed in descending order. RESULTS: In relation to the normal percentile curves, it is possible to display an individual normalised rim/disc area ratio curve. We obtained such curves for a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. CONCLUSION: We present a new display mode for the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for easy and reliable assessment of the local, diffuse and combined components of glaucomatous optic nerve head damage depending on optic disc size.     

Clinicopathological characteristics of skipping lymph node metastases in patients with colorectal cancer

We evaluated the optic disc in 77 eyes of 77 normal volunteers using a scanning laser tomograph (Heidelberg Retina Tomograph: HRT, version 1.11). Particular attention was paid to age, refractive error, and disc size. The topographic parameters included: cup area, C/D area ratio, rim area, cup volume, rim volume, mean cup depth, maximum cup depth, cup shape measure, height variation contour, mean RNFL thickness, and RNFL cross section area. There was a significant decline in mean RNFL thickness and RNFL cross section area with increase in age (p < 0.05). The mean and maximum cup depths were significantly deeper in myopic eyes (p < 0.05). Large discs had large values of cup area, C/D area ratio, rim area, cup volume, mean cup depth, cup shape measure (p < 0.01), and maximum cup depth (p < 0.05). Large discs had small values of mean RNFL thickness and RNFL cross section area. Rim volume was independent of age, refractive error, or disc area.     

Effect of the contour line on cup surface using the Heidelberg Retina Tomograph

BACKGROUND: Significance of topometric follow-up examinations of the optic nerve head in glaucomatous eyes depends on the reproducibility of the calculated parameters. Since the definition of the standard reference plane in software version 1.11 of the Heidelberg Retina Tomograph has been changed, intrapapillary parameters depend directly on the position of the contourline in the sector between -10 degrees to -4 degrees, and therefore on the observer variability to determine the disc border. We evaluated intra- and interobserver variability and present a simple approach to increase reproducibility. METHOD: The disc border of 4 glaucomatous eyes, 3 ocular hypertensive eyes and 3 eyes of healthy subjects were traced by two observers, 5 times using the free draw mode and 5 times by the addition of contourline circles. RESULTS: We found a median variability of the mean disc radius in sector -10 degrees to -4 degrees of 51 microns, which defines the position of the standard reference plane, resulting in a median variability of the position of the standard reference plane of 33 microns which caused a variability of 81 microns2 of the cup area. Addition of contourline circles smoothing the final contourline along the border of the optic disc resulted in a decrease of the coefficient of variation of the standard reference plane of 3.76% (6.76% vs. 3.0%), of the cup area of 2.34% (3.87% vs. 1.53%) and of the rim volume of 3.41% (9.75% vs. 6.34%). CONCLUSION: The calculation of the cup area using software version 1.11 of the Heidelberg Retina Tomograph depends on observer variability. The addition of contourline circles to define the final contourline along the disc border increases reproducibility. However, in follow-up of topometric examinations of the optic nerve head the software supported transfer mode should be used. Comparing topometric data of an individual optic disc in follow-up suppose the same definition of the contourline. Therefore, topometric data evaluated using software version 1.10 or earlier needs to be recalculated.     

Determination of long-life radiocesiums Cs-134 and Cs-137 in food by gamma-ray spectrometry: summary of collaborative study

PURPOSE: The authors evaluated the ability of a confocal scanning laser ophthalmoscope to detect glaucomatous visual field loss by using their previously described discriminant formula on a prospectively obtained cohort. The relationship of optic disc size to diagnostic classification was also evaluated. METHODS: One eye was chosen randomly from each of 153 subjects. Sixty control eyes had intraocular pressure less than 21 mmHg and normal visual fields; 93 glaucomatous eyes had intraocular pressure greater than 21 mmHg and abnormal visual fields. The optic disc status purposely was not used for classification purposes. All subjects were examined with the Heidelberg Retina Tomograph (HRT; Heidelberg Engineering GMBH, Heidelberg, Germany) and Humphrey Perimeter, program 30-2 (Humphrey Instruments, Inc., San Leandro, CA). Visual fields were considered abnormal by the authors' previously published criteria. The HRT classification used age, adjusted cup shape measure, rim volume, and height variation contour to classify the optic disc as normal or glaucomatous. Then the authors assessed the sensitivity, specificity, and diagnostic precision for the entire group, and for three subsets classified by disc area: disc area less than 2 mm2, between 2 and 3 mm2, and more than 3 mm2. RESULTS: The entire group had a sensitivity, specificity, and diagnostic precision of 74%, 88%, and 80%, respectively. The specificity was 83% when disc area was less than 2 mm2 and improved to 89% when disc area was more than 2 mm2. The sensitivity tended to improve from 65% to 79%, and to 83% if the disc area increased, but the difference was not statistically significant. CONCLUSIONS: In a prospective cohort of patients, the HRT discriminant analysis formula was capable of detecting glaucomatous visual field loss with good precision. Unusually small optic discs continue to present diagnostic difficulties.     

Identification of early glaucoma cases with the scanning laser ophthalmoscope

PURPOSE: This study aimed to define the confocal laser scanning ophthalmoscope (Heidelberg Retina Tomograph [HRT]) parameters that best separate patients with early glaucoma from normal subjects. STUDY DESIGN: A cross-sectional study. PARTICIPANTS: A total of 80 normal subjects and 51 patients with early glaucoma participated (average visual field mean deviation = -3.6 dB). INTERVENTION: Imaging of the optic nerve head with the HRT and analysis using software version 1.11 were performed. MAIN OUTCOME MEASURES: The relation between neuroretinal rim area and optic disc area, and cup-disc area ratio and optic disc area, was defined by linear regression of data derived from the normal subjects. The normal ranges for these two parameters were defined by the 99% prediction intervals of the linear regression between the parameter and optic disc area, for the whole disc, and for each of the predefined segments. Normal subjects and patients were labeled as abnormal if the parameter for either the whole disc or any of the predefined segments was outside the normal range. The sensitivity and specificity values of the method were calculated. RESULTS: The highest specificity (96.3%) and sensitivity (84.3%) values to separate normal subjects and those patients with early glaucoma were obtained using the 99% prediction interval from the linear regression between the optic disc area and the log of the neuroretinal rim area. Similar specificity (97.5%) and lower sensitivity (74.5%) values were obtained with the 99% prediction interval derived from regression between the disc area and cup-disc area ratios. Poor separation between groups was obtained with the other parameters. CONCLUSIONS: The HRT, using the technique of linear regression to account for the relationship between optic disc size and rim area or cup-disc area ratio, provides good separation between control subjects and patients with early glaucoma in this population.     

Change in optic disk topography after trabeculectomy

PURPOSE: To investigate the relationship between optic disk topography and intraocular pressure before and after trabeculectomy with confocal scanning laser ophthalmoscopy. METHODS: The eyes of 49 consecutive patients undergoing trabeculectomy at a university-based glaucoma practice underwent preoperative and postoperative imaging using a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph). Three images of one eye of each patient were obtained with a 15-degree field of view. Preoperative images were obtained approximately 2 months before surgery (mean +/- SD, 2.4 +/- 1.6 months). Postoperative images were obtained at least 3 months after surgery (mean, 4.5 +/- 2.6 months). RESULTS: Mean preoperative intraocular pressure, postoperative intraocular pressure, and percent change in intraocular pressure respectively were 23.1 +/- 6.8 mm Hg, 12.7 +/- 7.1 mm Hg, and 43.8% +/- 29.9%. A significant association (P < .01) was found between percent decrease in intraocular pressure and decreases in cup area, cup volume, and cup/disk area ratio as well as between percent decrease in intraocular pressure and increases in rim area, rim volume, mean height contour, retinal cross-section area, and height in contour. Between 11.7% and 31.2% of the variability (R2) in these parameters was explained by the percent change in intraocular pressure. Topography changes were more strongly associated with percent change than with mean change in intraocular pressure. We found no association between percent decrease in intraocular pressure and reference plane height or maximum cup depth. CONCLUSIONS: Changes in optic nerve topography were associated with reduction in intraocular pressure after trabeculectomy.     

High levels of serum allopregnanolone in women with premature ovarian failure

BACKGROUND: Blue-on-yellow (B/Y) perimetry can reveal visual field defects earlier and larger in extent than white-on-white (W/W) perimetry. The Heidelberg Retina Tomograph (HRT) produces a three-dimensional image of the optic disc. The aim of this study was to compare the strength of the association of the B/Y and W/W visual hemifield mean deviation (HMD) variables with the optic nerve head (ONH) morphological variables of the respective area. METHODS: We evaluated one randomly chosen eye of 40 normal subjects and 37 patients with ocular hypertension and different stages of glaucoma. The B/Y and W/W visual fields (program 30-2) were obtained with a Humphrey perimeter. Results of both visual fields were adjusted for the patient's age and lens transmission index measured with a lens fluorometer. HMD was calculated as the difference between the measured and expected hemifield mean sensitivity values, predicted by the regression model fitted in our nonglaucomatous subject data. The HRT with the software version 1.11 was used to acquire and evaluate the topographic measurements of the optic disc. RESULTS: The B/Y and W/W visual field HMDs showed statistically significant correlation with ONH parameters such as cup shape measure (CSM), rim volume, rim area, mean retinal nerve fiber layer (RNFL) thickness and RNFL cross-sectional area. With forward stepwise logistic regression analysis using B/Y hemifield data 38% of the glaucoma patient's normal W/W hemifields were classified abnormal. With the CSM alone in the model 52% of the cases were classified abnormal. CONCLUSIONS: B/Y visual field hemifield mean deviation values correlate well with ONH parameters examined with the HRT.     

Laser scanning tomography of the optic nerve head in ocular hypertension and glaucoma

BACKGROUND: This study evaluated the ability of laser scanning tomography to distinguish between normal and glaucomatous optic nerve heads, and between glaucomatous subjects with and without field loss. METHODS: 57 subjects were classified into three diagnostic groups: subjects with elevated intraocular pressure, normal optic nerve heads, and normal visual fields (n = 10); subjects with glaucomatous optic neuropathy and normal visual fields (n = 30); and subjects with glaucomatous optic neuropathy and repeatable visual field abnormality (n = 17). Three 10 degrees image series were acquired on each subject using the Heidelberg retina tomograph (HRT). From the 14 HRT stereometric variables, three were selected a priori for evaluation: (1) volume above reference (neuroretinal rim volume), (2) third moment in contour (cup shape), and (3) height variation contour (variation in relative nerve fibre layer height at the disc margin). Data were analysed using analysis of covariance, with age as the covariate. RESULTS: Volume above reference, third moment in contour, and mean height contour were significantly different between each of the three diagnostic groups (p < 0.001). Height variation contour showed no significant difference among the three diagnostic groups (p = 0.906). CONCLUSIONS: The HRT variables measuring rim volume, cup shape, and mean nerve fibre layer height distinguished between (1) subjects with elevated intraocular pressures and normal nerve heads, and glaucomatous optic nerve heads, and (2) glaucomatous optic nerve heads with and without repeatable visual field abnormality. This study did not directly assess the ability of the HRT to identify patients at risk of developing glaucoma. It is hypothesised that the greatest potential benefit of laser scanning tomography will be in the documentation of change within an individual over time.     

Aging changes of the optic nerve head in relation to open angle glaucoma

AIMS: To determine the age related changes in optic nerve head structure in a group of normal subjects and assess the significance of any changes in relation to those found in open angle glaucoma. METHODS: A group of 88 white volunteers and friends and spouses of patients with a normal visual field and normal intraocular pressure was studied. Two different imaging and measurement devices were used (computer assisted planimetry and scanning laser ophthalmoscopy), and the results from each were compared. Measurements were made of the optic disc, optic cup, and neuroretinal rim areas, and the vertical optic disc diameter and cup/disc diameter ratio. RESULTS: Neuroretinal rim area declined at the rate of between 0.28% and 0.39% per year. Vertical optic cup diameter and optic cup area increased with age. The mean cup/disc diameter ratio increased by about 0.1 between the ages of 30 and 70 years. CONCLUSIONS: Age related changes are significant and measurable, and should be taken into account when assessing the glaucoma suspect, and when estimating the rate of progression of glaucomatous optic neuropathy in patients with established disease.     

PDGF and TGF-beta induce cell shape changes in invertebrate immunocytes via specific cell surface receptors

BACKGROUND: To compare neuroretinal rim area measurements by confocal scanning laser tomography and planimetric evaluation of optic disc photographs. METHODS: For 221 patients with primary and secondary open angle glaucoma, 72 subjects with ocular hypertension, and 139 normal subjects, the optic disc was morphometrically analysed by the confocal scanning laser tomograph HRT (Heidelberg retina tomograph) and by planimetric evaluation of stereo colour optic disc photographs. RESULTS: Absolute rim area and rim to disc area were significantly (p < 0.0001) larger with the HRT than with planimetric evaluation of photographs. Differences between the two methods were significantly (p < 0.01) larger in normal eyes with small cupping than in normal eyes with large cupping, and differences were significantly (p < 0.01) larger in glaucomatous eyes with marked nerve damage than in glaucomatous eyes with moderate nerve damage. Coefficients of correlations between rim measurements of both methods were R2 = 0.60 for rim to disc area and R2 = 0.33 for absolute rim area. Planimetric measurements of rim area correlated significantly (p < 0.05) better than HRT determinations of rim area with mean visual field defect and retinal nerve fibre layer visibility. CONCLUSIONS: Measurements of absolute rim area and rim to disc area are significantly larger with the HRT compared with planimetry of disc photographs. Differences between both methods depend on disc area, cup size and glaucoma stage. The reason may be that the HRT measures the retinal vessel trunk as part of the neuroretinal rim. The differences between both methods, which should be taken into account if disc measurements performed by both methods are compared with each other, may not influence the main advantage of the HRT--that is, morphological follow up examination of patients with glaucoma.     

Reproducibility of topometric data with a scanning laser ophthalmoscope in rabbits

The Heidelberg Retina Tomograph is a confocal scanning laser ophthalmoscope which obtains three-dimensional images of the optic nerve head and the retina in the human eye. Because of its potential investigative uses in experimental animal models of glaucoma, we examined its variability with optic nerve head measurements in the rabbit eye. Three topographic images, recorded on different days, were acquired from the right eye of 5 New Zealand white rabbits over 3 weeks. To estimate the lowest possible variability, a second series of three images was recorded in a single setting without displacement of the rabbits. The average coefficient of variability (standard deviation/mean) for the estimate of the optic nerve head cup volume (volume below surface) was 11.1% in the independent series and was decreased to 3.0% in the sequentially recorded series without displacement of the rabbits (P < 0.001). These values indicate a comparable variability for the estimate of the optic nerve head cup volume in the rabbit compared with those reported for the human eye. This variability is considerably decreased by maximally standardizing the image acquisition position, suggesting that variability largely depends on the alignment between the subject and the laser-scanner.     

Prosthetic arteriovenous fistulas and venous anastomotic stenosis: influence of a high flow velocity on the development of intimal hyperplasia

OBJECTIVE: To search a sensitive parameter for the early diagnosis of primary open angle glaucoma (POAG). METHOD: A system of computerized image analysis was used to acquire images of the optic nerve head of patients with POAG, suspect glaucoma (SG) and of normal persons. Each of these groups contained 31 eyes of 31 cases. The mean relative depths of disc rim and cup at different areas in the optic nerve head were measured. All these patients were followed up for four to six months, and the changes of the mean depths of every sector were compared between each pair of the three groups with statistic analysis. RESULTS: The mean depth of the neural rim and cup of each sector and that of total rim and total cup of POAG and SG patients were all deeper than that of normal controls. The mean depths of neural rim of the superior sector, inferior sector and the total rim area of POAG were deeper than that of SG patients. Compared to their first measurements, the changes of mean depths of neural rim of superior sector and total neural rim area of POAG patients were more prominent than that of normal controls and SG. We also compared the relative depth of the total rim area in the different areas in the optic nerve head with other two dimensional optic disc parameters such as cup/disc ratio, etc. CONCLUSION: Our study suggests that three-dimensional stereoscopic measurement of the surface of optic nerve head and follow-up be of paramount importance in the early diagnosis of POAG patients.     

Pulmonary involvement in systemic lupus erythematosus

BACKGROUND: We wanted to find out whether the borders of the blind spot depend on the surface topography of the optic disc and its surrounding area. PATIENTS AND METHODS: We therefore examined ten eyes with parapapillary atrophy adjacent to the temporal side of the disc. Fundus perimetry was performed under direct fundus control using a Rodenstock scanning laser ophthalmoscope. We examined the horizontal meridian of the optic discs in 0.5 degree steps using Goldmann IV-stimuli with 10 different degrees of brightness and the Goldmann stimulus 1, 0 dB (greatest luminance). Six eyes with symmetric, "normal" excavation served as controls. Optic disc topography was measured with the Heidelberg Retina Tomograph (HRT). RESULTS: Stimuli with a large luminance power (Goldmann IV, 4 dB) were seen up to 0.8 degree centrally (i.e., towards the optic disc center) from the temporal edge of the parapapillary atrophy, but up to 1.9 degrees centrally from the nasal optic disc border (P < 0.01). Horizontal HRT section profiles of the optic disc consistently showed prominent nasal disc borders contrasting with a shallow excavation within the temporal parapapillary atrophy. In all six subjects with a normally shaped disc there was no such "nasotemporal asymmetry." CONCLUSIONS: The size of scotomas depends on the surface topography of the tested area. The prominent nasal part of the optic disc appears less "blind" than the shallow temporal part, probably due to more intensive light scattering by the prominent nasal part of the disc.     

Neuroretinal rim width ratios in morphological glaucoma diagnosis

AIMS: To evaluate the inferior to temporal neuroretinal rim width ratio and superior to temporal rim width ratio as measures of rim shape for diagnosis of glaucoma. METHODS: Colour stereo optic disc photographs of 527 normal subjects, 100 ocular hypertensive individuals with normal visual fields, and 202 open angle glaucoma patients with a mean perimetric defect of less than 10 dB were morphometrically evaluated. Eyes with an optic cup area of < 0.2 mm2 were excluded. RESULTS: In the normal subjects, inferior to temporal rim width ratio (1.67 (SD 0.53)) was significantly (p < 0.0001) higher than superior to temporal rim width ratio (1.56 (0.49)). Both ratios were significantly (p < 0.0001) higher the more vertically the optic disc was configured. In the normal eyes, both ratios were statistically independent of disc size, rim area, refractive error, age, and sex. With the differences being more marked for the inferior to temporal ratio than for the superior to temporal ratio, both rim width ratios were significantly (p < 0.005) lower in the ocular hypertensive group than in the normal group. Despite the high significance of the differences, diagnostic power of the inferior ratio and the superior ratio was 59% and 58%, respectively, indicating a marked overlap between the groups. CONCLUSIONS: Abnormally low inferior to temporal and superior to temporal rim width ratios can indicate glaucomatous optic nerve damage in some ocular hypertensive eyes. Being independent of optic disc size and ocular magnification, the rim width ratios may be taken as one among other variables for the ophthalmoscopic optic disc evaluation, taking into account, however, a pronounced overlap between normal eyes and ocular hypertensive eyes.     

Erythrocyte sodium-lithium countertransport activity and total body insulin-mediated glucose disposal in normoalbuminuric normotensive type 1 (insulin-dependent) diabetic patients

PURPOSE: To assess the potential of a clinical method of optic disc measurement in the detection of early neuroretinal rim loss in glaucoma. METHODS: A method of disc biometry based on indirect ophthalmoscopy was used to estimate disc and neuroretinal rim areas in 81 ocular hypertensive eyes of 43 patients and in 28 fellow eyes with normal visual fields of patients with unilateral visual field loss from primary open-angle glaucoma. The results were compared with those from age-matched visually normal patients. RESULTS: Neuroretinal rim area was significantly smaller in both hypertensive and fellow eye groups compared with controls (P < 0.0001; P = 0.0009). Disc area also was smaller in both groups (P = 0.0034; P = 0.046); however, this was inadequate to explain the differences in rim area, which, when corrected for disc size, were still highly significant (P < 0.0001; P = 0.0001). CONCLUSION: The differences in neuroretinal rim area observed are likely to indicate that a proportion of the eyes studied had suffered a reduction of neuroretinal rim area, which was measurable by this method at a stage before the development of demonstrable visual field loss.     

Use of scanning laser ophthalmoscopy to monitor papilloedema in idiopathic intracranial hypertension

AIMS: To determine the sensitivity of confocal scanning laser ophthalmoscopy (SLO) in detecting clinically significant changes in papilloedema secondary to idiopathic intracranial hypertension (IIH) and the correlation with visual field loss. METHODS: Eight patients--three new, two recurrent, and three chronic cases of IIH--were examined over a 9 month period with SLO (Heidelberg retina tomograph) of optic nerve head and 30-2 Humphrey visual fields (six cases). Optic disc swelling (volume) was assessed in each eye using a circular contour line placed around the swollen optic nerve head on the mean image of three topographic images. Nine volume measurements from single images in each eye of every patient were performed on one occasion to assess repeatability. RESULTS: In the five acute cases optic disc volumes (range 1-16 mm3) decreased with treatment to stable, normal levels. Three of these had mild, reproducible, field defects which resolved. Two chronic cases had stable or fluctuating disc volume with no detectable change in grade of papilloedema and mild field loss. In one case which underwent theco-peritoneal shunting both disc volume and field worsened, indicating therapeutic failure. Both improved postoperatively. CONCLUSIONS: SLO has a high sensitivity for detecting small changes in disc volumes and correlates closely with visual field change in the short term. It can confirm therapeutic failure by detecting stable or increasing disc volume. Decreasing volume may indicate resolution of papilloedema or secondary optic atrophy, so accompanying funduscopy and visual fields remain essential.     

The variation and covariation of cup and disc diameters

The variation and covariation of cup and disc diameters were studied in a material derived from a population survey and consisting of 2,334 fundus photographs from as many eyes in 1,322 subjects. A simple device was used to facilitate focusing of the camera. The colour slides were projected on to a screen at a fixed distance and measured on ruled paper. The effect of refraction on the magnification in the eye-camera system was compensated by the use of a simple correcting factor. Some apparently quite normal discs, nevertheless, had an area more than four times larger than that of other equally normal ones. The sizes of discs and cups covaried, however, to a suprisingly great extent (r = 0.8) and changes in disc diameter were in general parallelled by similar changes in cup diameter. The amount of tissue in the optic nerve head therefore varied somewhat less than the disc size. Cup diameters were widely dispersed, unevenly distributed and heavily dependent on disc size. The "average rim breadths", on the other hand, were much less dispersed, normally distributed and independent on the disc diameter. By taking the covariation of cup and disc diameters into account the detection of any enlargement or diminution of the optic cup ought to be facilitated.     

The relationship between deterioration and reversal of optic disc cupping in monkeys with chronic experimental high-pressure glaucoma

PURPOSE: To investigate the correlation between the deterioration in optic disc cupping during the chronic elevation of intraocular pressure (IOP) and the reversal of cupping during a subsequent reduction in IOP in experimental glaucoma. METHODS: We examined changes in the vertical and horizontal cup to disc ratios, the rim area to disc area ratio, and the cup volume to disc area ratio in 11 monkey eyes with laser-induced glaucoma using computerized stereo-image analysis. Correlations between changes in disc parameters during a spontaneous IOP reduction and changes in disc parameters during a period of chronic IOP elevation from baseline before laser exposure (baseline) to before the IOP reduction (pre-IOP reduction) and during the period from baseline to after the reduction in IOP (post-IOP reduction) were determined by linear regression analysis. RESULTS: All disc parameters improved significantly during IOP reduction and deteriorated significantly during the periods from baseline to the pre-IOP reduction and from baseline to the post-IOP reduction. The degree of reversal in disc parameters was correlated with the deterioration from baseline to the pre-IOP reduction and from baseline to the post-IOP reduction in the vertical cup to disc ratio (r = 0.68, P = 0.0218 and r = 0.97, P < 0.0001, respectively), the horizontal cup to disc ratio (r = 0.57, P = 0.0649 and r = 0.98, P < 0.0001, respectively), the rim area to disc area ratio (r = 0.68, P = 0.0227 and r = 0.98, P < 0.0001, respectively), and the cup volume to disc area ratio (r = 0.67, P = 0.0256 and r = 0.88, P = 0.0004, respectively). CONCLUSION: The degree of deterioration in cupping from baseline before the induction of glaucoma may be an important determinant of the degree of cupping reversal during subsequent reductions in IOP in primate glaucoma.     

Optic disc morphology in eyes after nonarteritic anterior ischemic optic neuropathy

PURPOSE: Parapapillary chorioretinal atrophy, neuroretinal rim loss, and a decrease of retinal vessel diameter have been described to occur in glaucomatous eyes. This study was conducted to evaluate the frequency and degree of these signs in nonarteritic anterior ischemic optic neuropathy (AION). METHODS: We evaluated morphometrically and compared stereo color optic disc photographs of 17 patients after AION, 184 patients with primary open-angle glaucoma, and 98 normal subjects. RESULTS: The optic disc area and retinal vessel diameter were significantly smaller and the visibility of the retinal nerve fiber bundles was significantly reduced in patients after nonarteritic AION compared with that of the normal subjects. The optic disc shape, area, and form of zones alpha and beta of the parapapillary chorioretinal atrophy and the size and form of the neuroretinal rim did not differ significantly between these two groups. In the group of eyes with glaucoma, the neuroretinal rim was significantly smaller and the parapapillary chorioretinal atrophy was significantly larger than in the group of eyes with AION. Visibility of the retinal nerve fiber bundles and retinal vessel caliber did not differ statistically between the eyes with AION and those with glaucoma. CONCLUSIONS: These results indicate that the parapapillary chorioretinal atrophy is not larger in eyes after nonarteritic AION compared with normal eyes. They show that the area and shape of the neuroretinal rim, as determined planimetrically, may not markedly change after nonarteritic AION. They confirm previous reports on a small optic disc size as a risk factor for nonarteritic AION. They agree with findings of a reduced retinal vessel caliber in eyes with optic nerve damage, independently of the cause.