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.     

Optic disk morphology in experimental central retinal artery occlusion in rhesus monkeys.

PURPOSE: To evaluate longitudinally the optic disk morphology of nonglaucomatous optic nerve damage secondary to retinal nerve fiber damage, using experimental central retinal artery occlusion in rhesus monkey eyes as a model. METHODS: This prospective study included 24 eyes of 16 monkeys. In eight eyes of eight animals, central retinal artery occlusion was produced by clamping the central retinal artery in the retrobulbar space. Occlusion was verified by fluorescein fundus angiography. The same eyes at baseline as well as the eight contralateral healthy eyes and eight monkey eyes with experimental high-pressure glaucoma served as control groups. Serially taken optic disk photographs were morphometrically evaluated. RESULTS: The area and shape of the neuroretinal rim and alpha zone and beta zone of parapapillary chorioretinal atrophy of eyes after central retinal artery occlusion did not vary significantly (P > .30) from the same eyes before central retinal artery occlusion nor from the normal contralateral eyes. In the glaucomatous eyes, the neuroretinal rim was significantly (P < .001) smaller and parapapillary atrophy significantly (P = .01) larger than in the eyes after central retinal artery occlusion. CONCLUSIONS: Experimental central retinal artery occlusion, in contrast to glaucoma, does not markedly change the size and shape of parapapillary atrophy and neuroretinal rim; this confirms previous clinical studies. Thus, assessment of parapapillary atrophy and neuroretinal rim may be helpful to differentiate between glaucomatous optic neuropathy and nonglaucomatous optic neuropathy secondary to retinal nerve fiber damage. Parapapillary atrophy is independent of decreased retinal blood perfusion and development of nonglaucomatous optic nerve atrophy following experimental central retinal artery occlusion.     

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.     

Parapapillary atrophy and retinal vessel diameter in nonglaucomatous optic nerve damage

Parapapillary chorioretinal atrophy and decreased retinal vessel diameter occur in glaucomatous eyes. To evaluate the frequency and degree of these signs in nonglaucomatous optic neuropathy, the authors evaluated morphometrically and compared 47 patients with nonglaucomatous optic nerve atrophy from extraocular causes with 292 patients with primary open-angle glaucoma and 179 normal subjects. Eyes with anterior ischemic optic neuropathy were excluded. The parapapillary atrophy was differentiated into a central zone (beta) with sclera and large choroidal vessels visible by ophthalmoscopy and a peripheral zone (alpha) with irregular pigmentation. Both zones did not differ significantly in the eyes with nonglaucomatous optic neuropathy and the normal eyes. In the glaucomatous eyes, they were significantly larger and occurred more frequently. The retinal vessel diameter was significantly smaller in both groups with optic nerve atrophy than in the normal group. It was concluded that decreased retinal vessel diameters unspecifically suggest optic nerve atrophy. Evaluation of parapapillary chorioretinal atrophy can be helpful in differentiating nonglaucomatous from glaucomatous optic neuropathy.     

Peripapillary atrophy in unilateral capsular glaucoma

Pairwise comparisons of peripapillary crescents and haloes were performed for 56 eyes of 28 patients with early or moderate unilateral capsular glaucoma and no signs of exfoliation in the contralateral eye. The eyes differed highly significantly in rim area, rim/disc area ratio, cup area, and cup volume. They did not differ in disc areas, scleral ring areas, or size of peripapillary crescents. In the nonglaucomatous and glaucomatous eyes a significant correlation existed between the intraocular pressure (IOP) and the area of peripapillary atrophy. The area of peripapillary atrophy was significantly correlated with the damage to the glaucomatous optic nerve head. We concluded that the area of peripapillary atrophy is largely an inborn feature, and that nerve fiber loss can occur without differences in the peripapillary tissues. Nevertheless, an IOP-induced change in the retinal pigment epithelium cannot be ruled out.     

New findings in the evaluation of the optic disc in glaucoma diagnosis

PURPOSE OF REVIEW: Ophthalmoscopical evaluation of the optic disc is a feasible and largely accessible method to diagnose glaucoma. Many qualitative parameters have been described in glaucomatous optic neuropathy. Considering individual variations in the details of topography or tissue components damaged by the glaucomatous process, however, adequate identification of glaucomatous optic disc signs requires training and experience. Without adequate guidelines of optic disc examination, the physician may miss important aspects that could lead to adequate diagnosis or identification of progression in a patient with established glaucoma. This paper presents a systematic approach for the examination of the optic disc and retinal nerve fiber layer to aid the detection of glaucoma. RECENT FINDINGS: Optic disc qualitative parameters are better than quantitative parameters in separating glaucomatous from normal eyes. The sequential evaluation of optic disc size, neuroretinal rim size and shape, retinal nerve fiber layer, presence of peripapillary atrophy, and presence of retinal or optic disc hemorrhages enhances the ability to detect glaucomatous damage and its progression. SUMMARY: Ophthalmologists should be familiar with glaucomatous optic disc signs that can be identified during clinical examination. A simple systematic approach may allow improved diagnosis and management of glaucoma.     

Follow up of focal narrowing of retinal arterioles in glaucoma

AIM: To evaluate whether focal narrowing of retinal arterioles increases with progressive glaucomatous optic neuropathy. METHODS: Focal narrowing of retinal arterioles and area of neuroretinal rim were morphometrically evaluated on colour stereo optic disc photographs of 59 patients with primary open angle glaucoma, 22 patients with normal pressure glaucoma, 11 patients with secondary open angle glaucoma, and 31 patients with ocular hypertension. Minimum follow up was 8 months. Focal arteriolar narrowing was quantified by calculating the ratio of the vessel width in the broadest to the narrowest vessel part. RESULTS: In the subgroup of patients with progressive glaucomatous optic nerve damage (n = 37), focal narrowing of retinal arterioles increased significantly (p < 0.005) with decreasing neuroretinal rim area. In the subgroup of patients with stable appearance of the optic disc (n = 86), focal narrowing of retinal arterioles did not change significantly (p = 0.79). The positive correlation between increasing focal thinning of retinal arterioles and progression of glaucomatous optic neuropathy was present, although not statistically significant, in all the glaucoma subtypes examined. The location of focal thinning of retinal arterioles did not change in the follow up. CONCLUSIONS: Focal narrowing of retinal arterioles increases significantly with progressive glaucomatous optic neuropathy, independent of the type of glaucoma. It is stable in patients with non-progressive glaucoma. The findings agree with previous reports on a higher degree of focal arteriole narrowing in eyes with pronounced optic nerve damage in comparison with those with moderate optic nerve atrophy or normal eyes. In the clinical management of patients with glaucoma, in some eyes, increasing focal arteriole narrowing may suggest progression of disease.     

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.     

Study of the optic papilla and nerve fiber layer in glaucoma]

BACKGROUND: For diagnosis and follow-up of glaucoma an exact evaluation of the optic nerve disc and the nerve fiber layer is necessary. METHODS: The slit-lamp evaluation of the optic nerve disc and nerve fiber layer is presented as well as the evaluation with the Nerve Fiber Analyzer and the Heidelberg Retina Tomograph. RESULTS: Signs of a glaucomatous optic disc include a difference of more than 0.2 in the vertical cup to disc (CD) ratio between the eyes, a vertical CD ratio exceeding more than 0.1 the horizontal, larger CD ratios in small optic discs, notching of the neuroretinal rim, an enlarged zone beta of parapapillary chorioretinal atrophy, and peripapillary hemorrhages. Atrophy of the nerve fiber layer may be localized or diffuse. Both types of atrophy may be present at the same time. CONCLUSIONS: Knowledge of all signs of the glaucomatous optic disc and forms of nerve fiber layer atrophy allows an earlier diagnosis of glaucoma and an earlier recognition of progression.     

Optic Disc Cupping in Arteritic Anterior Ischemic Optic Neuropathy Resembles Glaucomatous Cupping

Five cases of anterior ischemic optic neuropathy secondary to biopsy-proven giant cell arteritis are presented. In each case, cupping of the optic disc, which closely resembled glaucomatous cupping, was observed in the affected eye. The presence of glaucoma was ruled out on the basis of normal intraocular pressures and normal tonographic measurements of facility of outflow. These cases indicate that arteritic ischemic optic neuropathy can result in optic disc cupping, which closely resembles glaucomatous cupping. The similarities in the appearance of cupping of these discs with that seen in eyes with glaucoma suggest that the pathogenesis of cupping in glaucoma and in arteritic ischemic optic neuropathy may share some common mechanisms.     

Monitoring of morphometric changes of optic discs with morphologic progression of glaucomatous optic atrophy by means of laser scanner tomography

AIM: Aim of this study was to measure morphometric changes in optic discs with laser-scanning tomography (HRT, Heidelberg-Retina-Tomograph, Heidelberg) in eyes with early glaucomatous morphologic progression. PATIENTS AND METHODS: 61 eyes of 36 patients with marked neuroretinal rim loss or its early morphologic signs (1. optic disc hemorrhages, 2. reduced visibility of the retinal nerve fiber layer (RNF), 3. appearance of narrowing of retinal vessels, 4. enlargement of the choroidal, parapapillary atrophy) were compared to 74 normal eyes of 39 probands. 15 degrees stereographs of the optic discs were evaluated for morphologic changes. The morphometric variables of the neuroretinal rim and excavation measured by the HRT were examined in the course of the disease. RESULTS: In the group of normals no significant changes of the neuroretinal rim in the course of 2.0 +/- 1.2 years were found. In the group of glaucomatous eyes (3.0 +/- 1.5 years follow-up) 34 eyes showed marked neuroretinal rim loss, 17 disc hemorrhages, 4 vessel narrowing, 3 an increased chorioidal atrophy, 3 a decreased visibility of the retinal nerve fiber layer. In these eyes a significant loss of rim area (p = 0.01) and an increase of excavation area (p = 0.0001) and volume (p = 0.003) was measured by the HRT. Only three eyes showed a perimetric loss of sensitivity (0.8-3.4 db) in Octopus static perimetry. CONCLUSIONS: Laser-scanning tomography of the optic disc seems to be able to measure morphometric changes in eyes with morphologic progression of glaucomatous optic atrophy, even before perimetric changes occur.     

Dark adaptation in glaucomatous and nonglaucomatous optic nerve atrophy

Optic nerve damage is associated with impairment of psychophysical functions. We measured dark adaptation in 21 eyes of 14 normal subjects, 35 eyes of 19 patients with primary open-angle glaucoma, and 7 eyes of 4 patients with nonglaucomatous descending optic nerve atrophy. In the normal subjects light thresholds and time of the shoulder in the dark adaptation curve increased significantly with age. In eyes with glaucomatous or nonglaucomatous optic nerve damage light sensitivity was lower than in normal eyes of age-matched control groups. Rod light sensitivity was significantly (P < 0.05) correlated with neuroretinal rim loss, parapapillary chorioretinal atrophy, and relative afferent pupillary defects. We conclude that velocity and degree of dark adaptation decrease with increasing age. Patients with glaucomatous and nonglaucomatous optic nerve atrophy show decreased light sensitivity especially in the rod part of dark adaptation worsening with advancing optic nerve damage.This study was supported by Deutsche Forschungsgemeinschaft DFG, grant no. Jo 155/2-1, and Dr. Helmut and Margarete Meyer-Schwarting-Stiftung     

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 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.     

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.     

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.     

Thickness of the lamina cribrosa and peripapillary sclera in Rhesus monkeys with nonglaucomatous or glaucomatous optic neuropathy

Purpose: To measure the thickness of the lamina cribrosa and peripapillary sclera in monkeys with a nonglaucomatous optic nerve damage and to compare that with those of monkeys with glaucomatous optic neuropathy. Methods: The study included 22 monkey eyes (Macaca mulatta) which had undergone a temporary experimental central retinal artery occlusion (CRAO) and seven monkey eyes in which experimental glaucoma was unilaterally produced. We measured histomorphometrically the thickness of the lamina cribrosa and peripapillary sclera. Results: The lamina cribrosa was significantly thicker in the CRAO group than in the glaucoma group (central region: 212 ± 46 μm versus 167 ± 17 μm; p = 0.009). The thickness of the peripapillary sclera at the optic disc border (253 ± 39 μm versus 192 ± 21 μm; p = 0.001) and outside of the optic nerve meninges (408 ± 70 μm versus 314 ± 64 μm; p = 0.006) was significantly greater in the CRAO group. Conclusions: In monkey eyes with a temporary CRAO as a model for nonglaucomatous optic nerve damage, the lamina cribrosa is significantly thicker than in monkey eyes with experimental glaucomatous optic nerve damage. It may suggest that the loss of optic nerve fibres might not be the reason for the thinning of the lamina cribrosa in eyes with advanced glaucoma. The thinner peripapillary sclera in the glaucomatous eyes may suggest that the monkey sclera is more vulnerable to stretching with increased intraocular pressure than the human eye for which no glaucoma‐related lengthening of the eyeball and thinning of the peripapillary sclera have been observed.     

Fluorescein angiographic characteristics of the optic disc in ischemic and glaucomatous optic neuropathy

Fluorescein angiography has been utilized to study the microvascular supply of the prelaminar optic disc and the peripapillary choroid. Observation of hypofluorescence of these structures both in patients with anterior ischemic optic neuropathy (AION) and with chronic open-angle glaucoma (COAG) has led to speculation as to the pathogenetic mechanism in each disorder. In AION, studies consistently show defective filling of the disc without atrophy, suggesting hypoperfusion as a primary mechanism. In COAG, defective filling is common, but typically occurs in regions of atrophy or increased cupping, which may show hypofluorescence as a nonspecific sequela of disc tissue loss. The hypofluorescence seen in some ocular hypertensive patients supports but does not confirm a primary vascular role in the pathogenesis of COAG. Peripapillary choroidal filling delay outside the range of normal is consistently seen in arteritic AION, but not in either nonarteritic AION or COAG. This finding suggests that any vasculopathy present in these disorders is distal within the branches of the posterior ciliary artery system.     

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.     

Correlation between a disc hemorrhage and peripapillary atrophy in glaucoma patients with a unilateral disc hemorrhage

PURPOSE: To investigate the correlation between a disc hemorrhage and peripapillary atrophy in glaucoma patients with a unilateral disc hemorrhage. METHODS: The 44 glaucoma patients (7 with primary open-angle glaucoma and 37 with normal-tension glaucoma) with a unilateral disc hemorrhage from June 1997 to November 2002 were selected randomly and included sequentially. The topographic measurements were performed using Heidelberg Retina Tomograph (HRT) within 3 months of detecting the disc hemorrhage. The zone beta parameters of the peripapillary atrophy were analyzed by the Atrophy Zone Analysis software. The intraocular pressure, refractive error, visual field parameters, and optic disc parameters were compared between both eyes. Univariate and multivariate regression analysis were performed. RESULTS: The area, angular and radial extent of the zone beta, and the ratio of the zone beta area to the disc area were significantly greater in the hemorrhagic eyes than in the contralateral eyes (P < 0.001). The prevalence of peripapillary atrophy was significantly higher in the hemorrhagic eyes (84%) than in the contralateral eyes (66%) (P = 0.034, chi2 test). The rim area and the rim volume of the hemorrhagic eyes were significantly smaller than those of the contralateral eyes (P = 0.02, < 0.001, respectively). In multivariate regression analysis, the peripapillary atrophy area was the independent significant factor associated with disc hemorrhage (P = 0.03, Odds Ratio = 1.51). The refractive error, intraocular pressure, Mean Deviation (MD), and Corrected Pattern Standard Deviation (CPSD) of the visual fields in both eyes were similar. CONCLUSION: The area and extent of the peripapillary atrophy was significantly greater and more prevalent in the eyes with a disc hemorrhage than in the contralateral control eyes. Peripapillary atrophy is closely associated with a disc hemorrhage in glaucoma patients irrespective of small neuroretinal rim area and volume.