Small neuroretinal rim and large parapapillary atrophy as predictive factors for progression of glaucomatous optic neuropathy

PURPOSE: To evaluate which morphologic features of the optic disc are predictive factors for progressive neuroretinal rim loss in chronic open-angle glaucoma. DESIGN: Prospective, observational case series. PARTICIPANTS: The study included 394 eyes of 257 white patients with chronic open-angle glaucoma. Mean follow-up time was 31.8 months (median, 39.7 months). Progression of glaucoma was defined as loss of neuroretinal rim as detected by disc photographs. Presence of optic disc hemorrhages was not taken into account. METHODS: All patients underwent repeated qualitative and morphometric evaluation of color stereo optic disc photographs. Statistical analysis included Kaplan-Meier curves, and bivariate and multivariate Cox regression analysis adjusted for patients' ages. Dependency of left and right eyes from the same subject was taken into account. MAIN OUTCOME MEASURES: Qualitative and quantitative morphologic optic nerve head parameters. RESULTS: Progression of glaucomatous optic nerve changes was detected in 42 eyes (11%). At baseline of the study, neuroretinal rim area (total area, P = 0.03) was significantly smaller, and beta zone of parapapillary atrophy (total area, P = 0.04) was significantly larger in the progressive study group compared with the nonprogressive study group. Neither study group varied significantly in size and shape of the optic disc, optic cup depth, alpha zone of parapapillary atrophy, and diameter of the retinal arteries and veins (P > 0.05). Multiple Cox regression analysis revealed that the progression of glaucoma depended significantly on the area of the neuroretinal rim (temporal sector, P = 0.003) and beta zone of parapapillary atrophy (temporal inferior sector, P = 0.02). CONCLUSIONS: Important morphologic predictive factors for progression of the glaucomatous appearance of the optic nerve head in white persons are small size of neuroretinal rim and large area of beta zone of parapapillary atrophy. Progression of glaucomatous optic nerve head changes is independent of size and shape of the optic disc, size of alpha zone of parapapillary atrophy, retinal vessel diameter, and optic cup depth.     

Optic disc morphology in pigmentary glaucoma

AIM—To evaluate the morphology of the optic nerve head in eyes with pigmentary glaucoma.
METHODS—Colour stereo optic disc photographs of 62 patients with pigmentary glaucoma and 566 patients with primary open angle glaucoma were morphometrically evaluated. By prestudy selection, mean visual field defect and neuroretinal rim area were not significantly different between the two groups (p=0.89 and p=0.45).
RESULTS—The pigmentary glaucoma group did not vary significantly (p >0.10) from the primary open angle glaucoma group in size and shape of the optic disc, configuration of neuroretinal rim, depth of optic cup, area of alpha zone of parapapillary atrophy, diameter of retinal vessels at the disc border, and frequency of disc haemorrhages and localised retinal nerve fibre layer defects. The beta zone of parapapillary atrophy was slightly, but not statistically significantly (p=0.06), smaller in the pigmentary glaucoma group. The mean maximal intraocular pressure and mean intraocular pressure amplitude were significantly (p<0.001) higher in the pigmentary glaucoma group.
CONCLUSIONS—In contrast with the characteristic morphology of the anterior segment and despite significantly higher intraocular pressure peaks and a larger pressure amplitude, eyes with pigmentary glaucoma compared with eyes with primary open angle glaucoma do not show a pathognomonic morphology of the optic disc and retinal nerve fibre layer. The slightly smaller beta zone of parapapillary atrophy may correspond to higher intraocular pressure in pigmentary glaucoma.

Keywords: optic disc morphology; pigmentary glaucoma; secondary open angle glaucoma     

Optic disc morphology after arteritic anterior ischemic optic neuropathy

OBJECTIVE: To evaluate the appearance of the nerve head in patients after giant cell arteritis-induced arteritic anterior ischemic optic neuropathy (A-AION). DESIGN: Noncomparative clinical case series. PATIENTS: The study comprised 29 patients who presented with unilateral A-AION and temporal artery biopsy-proven giant cell arteritis. Stereoscopic optic disc photographs, taken of both the affected and unaffected eyes at the onset of the disease and after a follow-up period of 20.10 +/- 25.36 months (median, 11 months; range, 2-102 months), were morphometrically evaluated. MAIN OUTCOME MEASURES: Size and shape of the optic disc, neuroretinal rim, optic cup, and alpha and beta zones of parapapillary atrophy. RESULTS: In the eyes after A-AION, at the end of the study, the neuroretinal rim was significantly (P = 0.002) smaller, and the optic disc cup area was significantly (P = 0.001) larger than those of the contralateral unaffected eyes. Alpha zone and beta zone of parapapillary atrophy did not vary significantly (P > 0.50). CONCLUSIONS: A-AION, like glaucomatous optic neuropathy, results in neuroretinal rim loss and optic disc cupping. However, in contrast to glaucoma, A-AION is not associated with an enlargement of parapapillary atrophy. The reasons and mechanisms responsible for these similarities and dissimilarities are discussed. Marked clinical, morphologic, and histopathologic similarities in optic disc cupping and loss of neuroretinal rim between A-AION and glaucomatous optic neuropathy are highly suggestive of a common mechanism for the development of the two diseases (i.e., ischemia of the optic nerve head). The subject is discussed at length.     

Morphologic predictive factors for development of optic disc hemorrhages in glaucoma

PURPOSE: To evaluate which optic disc parameters are predictive factors for the development of disc hemorrhages in chronic open-angle glaucoma. METHODS: The prospective comparative clinical observational study included 432 eyes of 281 white patients with chronic open-angle glaucoma. Mean follow-up time was 38.8 months (median, 31.5). Eyes in the whole study group were divided into those with an optic disc hemorrhage during the follow-up period (hemorrhagic group; n = 38; 8.8%), those without disc hemorrhages and with neuroretinal rim loss as sign of progression of glaucoma (rim loss group; n = 42; 9.7%), and those with neither disc hemorrhages nor neuroretinal rim loss (stable group; n = 352; 81.5%). Color stereo optic disc photographs were obtained repeatedly in all patients and subjected to qualitative and morphometric evaluation. RESULTS: At baseline, neuroretinal rim area was significantly (P < 0.03) smaller and the beta zone of parapapillary atrophy (temporal lower sector) was significantly (P < 0.03) larger in the hemorrhagic group than in the stable group. Both study groups did not vary significantly (P > 0.05) in optic disc size and shape, optic cup depth, alpha zone of parapapillary atrophy, and retinal vessel diameter. In multivariate analysis, the neuroretinal rim area was the only significant predictor of hemorrhages. The hemorrhagic group and the rim loss group did not differ significantly (P > 0.05) in any optic disc parameter measured. CONCLUSIONS: In chronic open-angle glaucoma, morphologic predictive factors for the development of disc hemorrhages are small size of neuroretinal rim and, possibly, a large parapapillary beta zone. Development of disc hemorrhages is independent of optic disc size and shape, size of alpha zone of parapapillary atrophy, retinal vessel diameter, and optic cup depth. Optic nerve heads in eyes with eventual development of disc hemorrhages and in eyes with eventual progressive rim loss without observed disc hemorrhages do not differ markedly in appearance.     

Iris colour, optic disc dimensions, degree and progression of glaucomatous optic nerve damage

PURPOSE: To evaluate whether iris colour influences size and shape of the optic nerve head and risk for glaucoma progression. METHODS: The hospital-based observational study included 1973 eyes of 1012 Caucasian subjects with ocular hypertension or chronic open-angle glaucoma. For all patients, colour stereo optic disc photographs were evaluated, and corneal pachymetry and achromatic perimetry were performed. Main outcome measures were optic nerve head parameters, the development or progression of visual field defects and iris colour. RESULTS: In most of the study groups, size of the optic disc, neuroretinal rim, alpha zone and beta zone of parapapillary atrophy, retinal vessel diameter and central corneal thickness did not differ significantly between eyes with blue, green, brown and mixed iris colour. In the normal-pressure glaucoma group, neuroretinal rim area was smallest in the population with mixed-coloured eyes and largest in the group of eyes with brown irides (P = 0.001 after correction for inter-eye dependency and multiple testing). For the ocular hypertensive subjects and glaucoma patients with follow-up examinations, the rate of development or progression of glaucomatous visual field loss was not significantly associated with iris colour (P = 0.060). CONCLUSIONS: In Caucasian subjects, iris colour does not have a major association with the size of the optic nerve head structures, central corneal thickness and retinal arterial diameter. In Caucasian patients with ocular hypertension or chronic open-angle glaucoma, an influence of iris colour on the risk for development or progression of glaucomatous visual field defects could not be confirmed.     

Influence of cilioretinal arteries on neuroretinal rim and parapapillary atrophy in glaucoma

PURPOSE: The pattern of neuroretinal rim loss and increase in the area of parapapillary atrophy in glaucoma depend on the localization of the central retinal vessel trunk in the lamina cribrosa. The purpose of the present study was to determine whether, in a similar way, the pattern of rim loss and progression of parapapillary atrophy are influenced by the presence and position of cilioretinal arteries. METHODS: Color stereo optic disc photographs (15 degrees) for morphometric evaluation of the optic nerve head were used to compare the appearance of the optic disc in 41 patients exhibiting unilateral or bilateral cilioretinal arteries in the temporal horizontal disc region with the optic disc morphology of 127 patients without cilioretinal arteries. The areas of the neuroretinal rim and alpha and beta zones of parapapillary atrophy were measured in the total disc and in four disc sectors. RESULTS: Eyes with and eyes without cilioretinal arteries did not differ significantly in the areas of neuroretinal rim and alpha and beta zones of parapapillary atrophy, when measured in the whole optic disc and in the four disc sectors separately; in ratios of the temporal horizontal area to total area of rim and parapapillary atrophy; and in the ratio of temporal horizontal rim area-to-nasal rim area, neither in an interindividual comparison nor in an intraindividual intereye comparison. CONCLUSIONS: In contrast to the position of the central retinal vessel trunk, presence and position of cilioretinal arteries do not markedly influence the pattern of neuroretinal rim loss and progression of parapapillary atrophy in glaucoma.     

The retinal nerve fiber layer in normal and glaucomatous eyes. II. Correlations

The retinal nerve fiber layer is different in normal and glaucomatous eyes. We correlated semi-quantitative data of the retinal nerve fiber layer of 398 eyes with chronic primary open-angle glaucoma and of 234 normal eyes with the intra- and parapapillary morphometric signs and with the perimetric indices. The three parameters "sequence of the fundus sectors concerning the best visibility of the retinal nerve fiber bundles", "visibility of the nerve fiber bundles", and "localized defects" were significantly (p less than 0.001) correlated to 1) area of the neuroretinal rim as a whole and in four different optic disc sectors, 2) neuroretinal rim width determined every 30 degrees, 3) optic cup area, diameters and form, 4) horizontal and vertical cup/disc ratios and the quotient of the horizontal to vertical cup/disc ratio, 5) area and width of zone "Alpha", zone "Beta", and the total parapapillary chorio-retinal atrophy, 6) diameter of the retinal vessels, 7) grade of a "tesselated fundus", and 8) the visual field loss. If only the inferior temporal and the superior temporal sectors were considered, the retinal nerve fiber bundles were less visible in that sector with the largest notch in the neuroretinal rim, the smaller neuroretinal rim area and width, the thinner retinal vessels, and the larger zone "Alpha", zone "Beta", and total parapapillary chorio-retinal atrophy. The glaucomatous changes in the retinal nerve fiber layer are correlated in time and location with the intra- and parapapillary and the perimetric alterations. Evaluation of the retinal nerve fiber layer is a useful method to detect a glaucomatous optic nerve damage.(ABSTRACT TRUNCATED AT 250 WORDS)     

Parapapillary retinal vessel diameter in normal and glaucoma eyes. II. Correlations

The juxtapapillary diameters of the superior temporal and inferior temporal retinal artery and vein have been shown to be significantly smaller in glaucomatous eyes than in normal eyes. They had been measured in 473 eyes of 281 patients with chronic primary open-angle glaucoma and in 275 eyes of 173 normal subjects. In the current study the vessel diameters were correlated with intra- and parapapillary morphometric data and visual field indices. Only one eye per patient and subject was taken for statistical analysis. The retinal vessel calibers were significantly (P less than 0.001) correlated with: (1) the area of the neuroretinal rim as a whole and in four different optic disc sectors; (2) the rim width determined every 30 degrees; (3) the optic cup area and diameters; (4) the horizontal and vertical cup/disc ratios and (5) the quotient of them; (6) the retinal nerve fiber layer score; (7) the area of the parapapillary chorioretinal atrophy; and (8) the visual field indices. In the same eye the vessel caliber was smaller in that sector where the neuroretinal rim loss was highest and the retinal fiber layer score lowest. In intraindividual comparison the vessels were smaller in that eye with less neuroretinal rim tissue and lower nerve fiber layer score. No significant correlations were found with the form of the optic disc, the area of the peripapillary scleral ring, side, sex and refraction. The correlation coefficients were not significantly different when the control group was matched for age. The parapapillary retinal vessel diameter decreases with advancing glaucomatous optic nerve damage. It is correlated with morphometric intra- and parapapillary glaucomatous changes and perimetric defects.     

Predictive factors of the optic nerve head for development or progression of glaucomatous visual field loss

PURPOSE: To evaluate which morphologic features of the optic disc are predictive factors for the development or progression of visual field loss in chronic open-angle glaucoma. METHODS: The prospective observational clinical study included 763 eyes of 416 white subjects with ocular hypertension and chronic open-angle glaucoma. During the follow-up time (mean, 67.4 months; median, 65.1; range, 6.2-104.5), all patients underwent repeated qualitative and morphometric evaluation of color stereo optic disc photographs and white-on-white visual field examination. Progression of glaucomatous visual field damage was defined by point-wise regression analysis for each of the 59 locations in the visual field. Outcome measures were qualitative and quantitative morphologic optic nerve head parameters. RESULTS: Development or progression of glaucomatous visual field defects was detected in 106 (13.9%) eyes. At baseline of the study, neuroretinal rim area was significantly (P < 0.002) smaller, the beta zone of parapapillary atrophy (P < 0.003, nasal sector) was significantly larger, and age was significantly higher (P < 0.003) in the progressive study group than in the nonprogressive study group. Both study groups did not vary significantly in size of the optic disc and the alpha zone of parapapillary atrophy. Cox proportional hazard regression analysis revealed that the progression of glaucomatous visual field loss depended significantly on the area of the neuroretinal rim (P < 0.001) and age (P < 0.001), but was independent of diameter of the retinal arterioles and veins. CONCLUSIONS: Morphologic predictive factors for development or progression of glaucomatous visual field defects in whites are small neuroretinal rim area and large beta zone of parapapillary atrophy. Age is an additional nonmorphologic parameter. Progression of glaucomatous optic nerve head changes is independent of the size of the optic disc and alpha-zone of parapapillary atrophy and retinal vessel diameter.     

Inter-eye differences in chronic open-angle glaucoma patients with unilateral disc hemorrhages

OBJECTIVE: Flame-shaped optic disc hemorrhages are a hallmark of glaucomatous optic neuropathy. The purpose of this study was to evaluate which parameters differ between companion eyes with and without an optic disc hemorrhage in patients with chronic open-angle glaucoma. DESIGN: Comparative (companion eye) observational case series. PATIENTS: The study included 99 white patients with bilateral chronic open-angle glaucoma and unilateral flame-shaped optic disc hemorrhages. METHODS: All patients underwent qualitative and morphometric evaluation of color stereo optic disc photographs. MAIN OUTCOME MEASURES: Size and shape of the optic disc, neuroretinal rim and parapapillary atrophy, diameter of the retinal vessels, intraocular pressure measurements, and both mean value and loss variance value of the visual field examination. RESULTS: In an intraindividual inter-eye comparison, the eyes with disc hemorrhages and the contralateral eyes without disc bleeding did not vary significantly (P > 0.20) in size and shape of the optic disc and neuroretinal rim, optic cup depth, size of alpha and beta zone of parapapillary atrophy, retinal vessel diameter, intraocular pressure measurements, refractive error, and perimetric indices. CONCLUSIONS: In bilateral chronic open-angle glaucoma, the development of unilateral optic disc hemorrhages does not depend on inter-eye differences in size and shape of the optic disc, neuroretinal rim and parapapillary atrophy, diameter of the retinal vessels, intraocular pressure measurements, or visual field loss.     

Optic nerve head appearance in juvenile-onset chronic high-pressure glaucoma and normal-pressure glaucoma

OBJECTIVE: To evaluate the appearance of the optic nerve head in chronic high-pressure glaucoma and normal-pressure glaucoma. DESIGN: Clinic-based cross-sectional study. PARTICIPANTS: The study included 52 eyes with normal-pressure glaucoma and 28 eyes with juvenile-onset primary open-angle glaucoma that served as models for chronic high-pressure glaucoma. METHODS: Color stereo optic disc photographs and wide-angle retinal nerve fiber layer photographs were morphometrically examined. MAIN OUTCOME MEASURES: Localized retinal nerve fiber layer defects; parapapillary chorioretinal atrophy; disc hemorrhages; optic cup shape; retinal arteriole narrowing. RESULTS: Both study groups did not vary significantly in count of localized retinal nerve fiber layer defects, size of parapapillary atrophy, optic cup depth, steepness of disc cupping, rim/disc area ratio, diameter of retinal arterioles, and frequency and degree of focal retinal arteriole narrowing. In normal-pressure glaucoma versus juvenile open-angle glaucoma, localized retinal nerve fiber layer defects were significantly broader, disc hemorrhages were found significantly more often and were larger, and neuroretinal rim notches were present more frequently and were deeper. CONCLUSIONS: Chronic high-pressure glaucoma and normal-pressure glaucoma show morphologic similarities in the appearance of the optic nerve head. The lower frequencies of detected disc hemorrhages and rim notches in high-pressure glaucoma may be due to a smaller size of hemorrhages and localized retinal nerve fiber layer defects in high-pressure glaucoma. Both glaucoma types have morphologic features in common, suggesting that they may possibly belong to a spectrum of the same pathologic process.     

Morphology of the optic papilla in glaucoma. II. Secondary chronic open angle glaucoma

Previous studies have shown that the chronic open-angle glaucomas form a heterogeneous spectrum of diseases which have in common an open anterior chamber angle and glaucomatous optic nerve damage. Purpose of this study was to evaluate whether the appearance of the optic disc shows specific features among various types of secondary chronic open-angle glaucoma. METHODS: Clinical data and color-stereo optic disc photographs of 126 patients with pseudoexfoliative glaucoma and 47 patients with pigmentary glaucoma were compared with those of 501 patients with primary open-angle glaucoma (POAG) and of 481 normal subjects. The glaucoma groups did not differ in neuroretinal rim nor in perimetric mean defect. RESULTS: Mean optic disc area was significantly smaller in the pseudoexfoliative glaucoma eyes (2.54 +/- 0.51 mm2 vs. 2.71 +/- 0.63 mm2, p = 0.03) than in the primary open-angle glaucoma eyes. The pigmentary glaucoma group did not vary significantly from the primary open-angle glaucoma group in size of the optic disc. No significant differences were found for neuroretinal rim area, configuration of neuroretinal rim, depth of optic cup and diameters of the retinal arterioles and venules at the disc border between the secondary glaucoma groups and the POAG group respectively. Size of zone beta of the parapapillary atrophy was slightly, but not significantly smaller in the secondary glaucoma groups than in POAG. In the secondary glaucoma groups, the maximal intraocular pressure measurements were significantly (p < 0.001) higher than in the group with POAG. All glaucoma groups had a significantly smaller neuroretinal rim, significantly smaller retinal arterioles, and significantly larger parapapillary atrophy compared to the normal group. CONCLUSIONS: Except of a slightly smaller optic disc in eyes with pseudoexfoliative glaucoma, eyes with secondary glaucoma due to pseudoexfoliation or due to pigmentary dispersion do not vary significantly in their optic disc morphology compared to POAG and do not show pathognomonic features of the optic disc despite marked changes in the anterior segment of the eye.     

Parapapillary retinal vessel caliber. II. Caliber reduction in eyes with glaucoma (a papillometric study of 309 eyes with chronic simple glaucoma compared with 264 normal eyes)

The diameter of the temporal superior or inferior artery and vein was measured at the optic disk border and 2 mm from the disk center in 309 nonselected eyes with chronic primary open-angle glaucoma. The values obtained were compared with those of 264 nonselected normal eyes. The calibers of both vessels were significantly larger in the normal eyes than in the glaucomatous ones (p = 0.000 or p less than 0.01; Wilcoxon-Mann-Whitney test). Their diameters diminished significantly (p less than 0.001) with decreasing width and area of the neuroretinal rim as a whole and when divided into different optic disk sectors, and with increasing optic cup area, horizontal and vertical cup/disk ratios, area of the subtotal to total parapapillary choriopigmentepithelioretinal atrophy, perimetric loss, and glaucoma stage. Thus, the caliber of the parapapillary retinal vessels decreases significantly with increasing glaucomatous optic nerve damage.     

Ranking of optic disc variables for detection of glaucomatous optic nerve damage

PURPOSE: To describe optic disc variables assessed by evaluation of clinical optic disc photographs and to compare sensitivity and specificity of these optic disc parameters in identifying patients with ocular hypertension who have nerve fiber layer defects and normal visual fields and patients with visual field defects. METHODS: The study included 500 normal subjects, 132 patients with ocular hypertension with retinal nerve fiber layer defects and normal visual fields (preperimetric glaucoma), and 840 patients with glaucomatous visual field defects. Color stereo optic disc photographs were morphometrically evaluated. RESULTS: Highest diagnostic power for the separation between the normal group and the preperimetric glaucoma group had the vertical cup-to-disc diameter ratio corrected for its dependence on the optic disc size, total neuroretinal rim area, rim-to-disc area ratio corrected for disc size, and cup-to-disc area ratio corrected for disc size. Diagnostic power was lower for rim area in the temporal inferior and temporal superior disc sector, cup area corrected for disc size, and horizontal cup-to-disc diameter ratio corrected for disc size. Less useful for the differentiation between the normal subjects and the preperimetric glaucoma group were size of zones alpha and beta of parapapillary chorioretinal atrophy, and ratios of neuroretinal rim width and rim area comparing various optic disc sectors with each other. CONCLUSIONS: In subjects with ocular hypertension with retinal nerve fiber layer defects and normal conventional achromatic visual fields, the vertical cup-to-disc diameter ratio corrected for optic disc size, total neuroretinal rim area, rim-to-disc area ratio, and cup-to-disc area ratio corrected for disc size are the most valuable optic disc variables for early detection of glaucomatous optic nerve damage. Correction for optic disc size is necessary for optic disc variables directly or indirectly derived from the optic cup. Parapapillary atrophy is less important in the early detection of glaucoma.     

Optic disc morphometry correlated with confocal laser scanning Doppler flowmetry measurements in normal-pressure glaucoma

PURPOSE: To examine the relationship between morphologic optic disc parameters and hemodynamic parameters as measured by confocal laser scanning Doppler flowmetry in patients with normal-pressure glaucoma. METHODS: The study included 91 eyes of 54 patients with normal-pressure glaucoma (mean age: 57.7 +/- 9.8 years), and 136 eyes of 77 age-adjusted normal controls. Color stereo optic disc photographs were morphometrically examined, and confocal laser scanning flowmetry (Heidelberg Retinal Flowmeter) in the neuroretinal rim inside of the optic disc, and in the retina close to the temporal and nasal border of the optic nerve head was performed. RESULTS: Mean confocal laser scanning flowmetric measurements in the neuroretinal rim, temporal parapapillary retina, and nasal parapapillary retina were significantly (P<0.03) lower in the normal-pressure glaucoma group than in the age-adjusted control group. Correspondingly, mean confocal laser scanning flowmetric measurements within the neuroretinal rim decreased significantly, with relatively low correlation coefficients, decreasing neuroretinal rim area (P = 0.016; correlation coefficient r2 = 0.026), and increasing mean visual field defect (P = 0.011; r2 = 0.029). Measurements were statistically independent of alpha zone (P = 0.38; r2 = 0.004) and beta zone (P = 0.57; r2 = 0.002) of parapapillary atrophy. CONCLUSIONS: Confocal laser scanning flowmetric measurements within the neuroretinal rim were lower in eyes with normal-pressure glaucoma than in age-matched normal eyes. Confocal laser scanning flowmetric measurements decrease with increasing glaucomatous optic nerve damage. There is, however, a marked variability preventing a clear relationship between stage of glaucoma and decrease in confocal laser scanning flowmetric measurements. The correlation between parapapillary atrophy and confocal laser scanning flowmetric measurements is not statistically significant in normal-pressure glaucoma.     

Glaucoma diagnosis of the optic disc using photography and planimetry

Ophthalmoscopically and on clinical optic disc photographs, the optic nerve head can be described by the following parameters: size and shape of the optic disc, size and shape of the neuroretinal rim, size and shape of the optic cup, size and shape of the alpha and beta zones of parapapillary chorioretinal atrophy, visibility of the retinal nerve fiber layer, diameter of the retinal arteries, presence and location of optic disc hemorrhages.     

Optic disc morphology in south India: the Vellore Eye Study

AIM: To evaluate the morphology of the optic nerve head in an unselected population group in south India. METHODS: The study included 70 subjects forming a population based sample, selected in a random manner. Mean age was 47.5 (SD 8.7) years, mean refractive error measured -0.07 (1.11) dioptres (range -4.50 to +2.50 dioptres). Optic disc slides were morphometrically analysed. RESULTS: Mean optic disc area measured 2.58 (0.65) mm(2). It was statistically independent of age and refractive error. Optic disc shape was slightly vertically oval. Mean neuroretinal rim area was 1.60 (0.37) mm(2). It was significantly and positively correlated with optic disc size and optic cup size. It was independent of age, sex, refractive error, and axial length. In all subjects included in the study, the rim was smallest in the temporal horizontal optic disc sector. Mean horizontal cup/disc diameter ratio (0.66 (0.07)) was significantly (p<0.001) higher than the mean vertical cup/disc diameter ratio (0.56 (0.08)). Both ratios were highly significantly (p <0.001) and positively correlated with optic disc size. The alpha zone of parapapillary atrophy (0.84 (0.29) mm(2)), and beta zone (0.13 (0.38) mm(2)), respectively, occurred in 69 (98.6%) subjects and in eight (11.4%) subjects, respectively. They were significantly larger in the temporal horizontal sector. The alpha zone was significantly (p<0.001) larger and occurred significantly more often than beta zone. Retinal arterioles and venules were wider, and in spatial correlation, the visibility of the retinal nerve fibre layer was significantly better, in the temporal inferior disc arcade and the temporal superior arcade than in the nasal superior arcade and the nasal inferior vessel arcade. Except for the absolute size measurements these optic nerve head parameters did not differ markedly (p >0.05) from the values found in white people. CONCLUSIONS: South Indians and white people do not show marked differences in the morphology of the optic nerve head as measured by morphometric optic disc parameters, with the possible exception of the absolute optic disc dimensions.     

Ophthalmoscopic appearance of the normal optic nerve head in rhesus monkeys

PURPOSE: To evaluate the ophthalmoscopic appearance of the normal optic disc, parapapillary region, and retinal nerve fiber layer in rhesus monkeys. METHODS: Color stereo fundus photographs of 17 normal eyes of 17 rhesus monkeys aged between 13 and 23 years were morphometrically evaluated. RESULTS: The neuroretinal rim was significantly (P: < 0.008) broadest in the inferior disc region followed by the superior disc region, the nasal region, and the temporal region. Retinal nerve fiber layer visibility was significantly highest in the inferior temporal fundus region followed by the superior temporal fundus region, the superior nasal fundus region, and the inferior nasal fundus region. It decreased significantly (P: < 0.001) with increasing age. The retinal arterioles were significantly (P: < 0.01) wider in the inferior temporal and superior temporal fundus regions than in the superior nasal and inferior nasal fundus regions. The alpha zone of parapapillary atrophy (14/17 or 82.4%) occurred significantly (P: < 0.001) more often than the beta zone (2/17 or 11.8%). In 15 eyes (88. 2%), the foveola was located inferior to a horizontal line drawn through the center of the optic disc. Neuroretinal rim shape and area and size of alpha and beta zones of parapapillary atrophy were independent of age. CONCLUSIONS: As in humans, in normal rhesus monkeys the neuroretinal rim has a typical physiologic configuration that spatially correlates with the retinal arteriole diameter, retinal nerve fiber layer visibility, and position of the foveola inferior to the center of the optic disc. Neuroretinal rim shape is independent of age. Retinal nerve fiber layer visibility decreases significantly with increasing age. These findings may be useful for the early detection and differentiation of experimental optic nerve damage in rhesus monkeys.     

原发性开角型青光眼视神经损害进展与眼压波动及视盘旁萎缩弧扩大的关系

目的 分析原发性开角型青光眼（POAG）视神经损害进展的相关危险因素。设计 回顾性病例系列。 研究对象 北京同仁医院眼科门诊确诊的POAG、随访3年以上、眼底照片及眼压资料完整的患者115例（197眼）。方法 将患者初次就诊和末次就诊的眼底图片在计算机图像处理软件下进行图像配准,通过叠加闪烁对比观察眼底病变的细微改变。平均随访（56.6±14.8）个月。青光眼视神经损害进展的标准为盘沿丢失进展或伴有视网膜神经纤维层缺损进展。主要指标 可能导致青光眼视神经损害进展的多因素Logistic回归分析。结果 视神经损害进展98眼,未进展99眼,进展率49.75%。单因素Logistic回归分析显示视神经损害进展与眼压波动（P=0.000）、峰值眼压（P=0.001）及随访时间（P=0.041）有关;卡方检验显示视神经损害进展与盘沿出血（P=0.02）及视盘旁萎缩弧扩大（P=0.000）有关。多因素Logistic 回归分析显示视神经损害进展与眼压波动（P=0.000）及视盘旁萎缩弧扩大（P=0.000）有关。视神经损害进展组与未进展组相比,眼压波动明显大,前者眼压波动值平均为（2.87±1.29）（0.89～7.21）,后者眼压波动值平均为（2.11±0.94）（0.25～4.97）;并且视盘旁萎缩弧扩大的比例明显增高,视神经损害进展组无β区萎缩弧者5眼（5.1%）,有β区萎缩弧扩大者75眼（76.53%）。结论 除峰值眼压外,过大的眼压波动及β区萎缩弧扩大是POAG视神经损害进展的重要危险因素。（眼科,2012,21：39-42）     

Central retinal vessel trunk exit and location of glaucomatous parapapillary atrophy in glaucoma

OBJECTIVE: To evaluate whether the position of the central retinal vessel trunk exit on the lamina cribrosa spatially correlates with the location of parapapillary atrophy in glaucoma. DESIGN: Clinic-based, observational, cross-sectional study. PATIENTS: Color stereo optic disc photographs of 95 patients with primary or secondary open-angle glaucoma and 65 healthy persons were morphometrically evaluated. The intrapapillary and parapapillary region was divided into four quadrants. We determined the position of the central retinal vessel trunk exit on the lamina cribrosa surface and measured the area of parapapillary atrophy and neuroretinal rim in the four quadrants. MAIN OUTCOME MEASURES: The area of neuroretinal rim and parapapillary atrophy and the position of the central retinal vessel trunk exit. RESULTS: Comparing measurements between opposite disc quadrants showed that beta zone of parapapillary atrophy was significantly (P < 0.05) larger and that the neuroretinal rim was significantly smaller when beta zone and neuroretinal rim were measured in the disc quadrant most distant to the central retinal vessel trunk exit, than if the beta zone and neuroretinal rim were measured in the quadrant containing the vessel trunk exit. Comparing measurements in the disc quadrants between eyes with different positions of the central retinal vessel trunk exit revealed that, in the respective disc quadrant, the beta zone was significantly larger and the neuroretinal rim was smaller in eyes with the vessel trunk exiting in the opposite disc quadrant than in eyes with the vessel trunk exit located in the respective disc quadrant where the measurements were obtained. CONCLUSIONS: Position of the central retinal vessel trunk exit on the lamina cribrosa influences the location of parapapillary atrophy in glaucoma. The longer the distance to the central retinal vessel trunk exit, the more enlarged is parapapillary atrophy and the smaller is the neuroretinal rim. This relationship agrees with the spatial relationship between glaucomatous neuroretinal rim loss and enlarged parapapillary atrophy in glaucoma. Diagnostically, it may indicate that, in eyes with an abnormal configuration of parapapillary atrophy or with an abnormal position of the central retinal vessel trunk exit, early glaucomatous rim changes should be looked for in the disc sector that is most distant to the central retinal vessel trunk exit and where parapapillary atrophy may be relatively large.