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At least 19 recordsLinked to original sources

Nonglaucomatous cupping of the optic disc.

Optic disc cupping is a consequence of myriad disorders. The anatomy and vasculature of the disc provide great insight into why, how, and when ODC occurs in various conditions. Approaches to distinguish glaucomatous from nonglaucomatous causes of ODC should rely on patient history, visual fields assessment, and funduscopic findings, as described. Cupping can be seen with neurological processes, including benign tumors, that are treatable. The clinician must remain vigilant to detect uncommon but potentially threatening forms of nonglaucomatous optic disc cupping.

Diagnosis, Differential↗

Progression from anomalous optic discs to visible optic disc drusen.

At age 5, a patient underwent fundus photography that disclosed elevated optic discs without drusen. A head computed tomography did not show optic nerve calcification. At age 9, no disc drusen were evident by ophthalmoscopy, but a CT now showed optic nerve calcification. At age 12, optic disc drusen were faintly evident on photographs; visual fields showed blind spot enlargement OD and an arcuate defect OS. At age 21, he had numerous discrete disc drusen in both eyes, disc pallor, and slight progression of the visual field defects. This case documents the progression from anomalous optic discs to ophthalmoscopically visible optic nerve drusen over a 16-year period.

Adult↗

The influence of age, gender, refractive error, and optic disc size on the optic disc configuration in Japanese normal eyes.

PURPOSE: To investigate the influence of age, gender, refractive error, and optic disc size on optic disc configuration in Japanese normal eyes. METHODS: Ninety-two eyes from 92 visually normal Japanese subjects (mean refractive error+/-SD: -1.26+/-2.25 D, range -8 D to +3 D) were examined using a confocal scanning laser tomograph, TopSS. The following disc parameters were investigated: disc size, total or quadrant C/D area ratio and neuroretinal rim area, half-depth area, volume below, and average cup depth. RESULTS: The disc diameter ( mean+/-SD: 1.84+/-0.16 mm) and disc size showed highly significant correlations with the C/D ratio (p<0.001) and the neuroretinal rim area (p<0.001). No other correlation was observed. CONCLUSION: These results indicate that the optic disc diameter and disc size have higher correlations with the optic disc configuration than age, gender, and refractive error in Japanese. These results are similar to those data reported for eyes of Caucasians or Afro Americans, and should be considered when optic discs are evaluated.

Adult↗

Evaluation of the influence of tilt of optic disc on the measurement of optic disc variables obtained by optical coherence tomography and confocal scanning laser ophthalmoscopy.

PURPOSE: To evaluate the relationship between optic disc variables measured by confocal scanning laser ophthalmoscopy (CSLO) and optical coherence tomography (OCT). METHODS: Fifty-one eyes in 27 non-glaucomatous patients were scanned using a CSLO-TopSStrade mark and an OCT-OCT 3000trade mark. The relationship between the following four optic disc variables-disc area (DA), cup area (CA), neuroretinal rim area (NRRA), and cup-disc area ratio (CDAR)-measured by CSLO and OCT were evaluated, and the relationship between these measurements and optic disc tilt was assessed. Horizontal (HD) and vertical diameters (VD) of the optic disc were measured from disc photographs, and by CSLO and OCT, and ratios (HD/VD) were then compared. RESULTS: There was a good correlation in DA, CA, and CDAR except NRRA between OCT and CSLO measurements. In eyes with a tilt >/=4 degrees, DA and NRRA were measured larger, and CDAR and CA were measured smaller by OCT than by CSLO. However, in the eyes with a tilt of <4 degrees, no significant differences in measurement of disc variables were observed for the two measurement systems. HD/VD measured from disc photographs was well correlated with those determined by CSLO (r = 0.741, P < 0.0001), however, it correlated poorly with those measured by OCT in whole study eyes (r = 0.410, P = 0.008) and in eyes tilted by >/=4 degrees, respectively (P = 0.280). CONCLUSIONS: Although CSLO and OCT measurements of the optic disc are highly correlated, discrepancy becomes prominent in eyes with a disc tilted >/=4 degrees. Therefore, analysis of the optic nerve head by OCT must be cautiously interpreted in eyes with a highly tilted disc.

Adolescent↗

Large optic discs in large eyes, small optic discs in small eyes.

The optic disc area, varying interindividually by a factor of 1:7, is correlated with the count of the retinal ganglion cell axons and photoreceptors. This study evaluated whether the variations in the disc size are additionally correlated with those of the coronary diameters of the globe. Fifty-three normal human donor eyes with a mean age of 54.2 +/- 19.6 years were included in the study. After performing a 16-mm corneoscleral trephination, the globes were fixed and the horizontal and vertical diameters of the globes were measured. We cut the globes into meridional slices sticking together at the posterior fundus region. The areas of the whole retina and the optic disc were planimetrically evaluated on photographs with a millimeter scale aligned. We found that the horizontal and vertical diameters of the globe were correlated with the optic disc size and the retinal surface area. Eyes with long horizontal and vertical diameters had a larger optic disc and a larger retinal surface area than eyes with short diameters. The results suggest the combination of large optic discs in large eyes and of small optic discs in small eyes. Taking into account the relatively low correlation coefficients of 0.3 and 0.4, the study also suggests the existence of other not-evaluated factors influencing the occurrence of large optic discs. The results go along with the reported association between a large optic disc area and a large cornea size.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The reproducibility of computerized boundary analysis for measuring optic disc pallor in the normal optic disc.

The optic discs of eight normal subjects were photographed on three separate visits under widely varying conditions. Each photograph was scanned by a television camera, converted to digital form, and then analyzed using computer image analysis techniques. The computer was programmed to delineate the boundary around the optic disc and the area of pallor. The percentage of disc pallor was then computed across the entire disc and for each disc quadrant. The reproducibility of the procedure was determined by evaluating several photographic parameters: camera flash intensity, film type, magnification, and centering of the disc in the photograph. The focus adjustment on the television scanner was also varied. Under carefully controlled conditions, results showed that the reproducibility of measuring the total percent of disc pallor was 2%. Results for reproducibility are also given for less than optimal conditions and for manual planimetry on the same set of photographs.

Computers↗

A comparison of stereoscopic and monoscopic evaluation of optic disc topography using a digital optic disc stereo camera.

AIMS: To compare stereophotographic and monophotographic optic disc assessments made using a digital optic disc stereo camera. METHODS: Stereo digital optic disc photographs of 150 selected patients who had presented to a glaucoma clinic were assessed by two masked observers on separate occasions using (1) the stereophotographs and a stereoviewer, (2) a single image from the same stereopair. Results were analysed for both right and left eyes separately. 95% tolerance limits for change (TC) and intraclass correlation coefficients (ICC) were calculated and a multivariate analysis using a general linear model for repeated measures was performed. RESULTS: A total of 201 optic disc images of 150 patients (84 females, 108 left eyes) were analysed. Mean age of patients was 64 years. The results for right eyes are as follows (similar results were obtained for left eyes). Intraobserver (stereoscopic compared to monoscopic) measurements of: horizontal cup:disc ratios (CDR), ICC = 0.5995 and 0.7269, TC = 34% and 27%; vertical CDR, ICC = 0.8298 and 0.817, TC = 25% and 27%; area CDR, ICC = 0.7757 and 0.8259, TC = 28% and 25%; circumference CDR, ICC = 0.7618 and 0.8103, TC = 28% and 25%. Interobserver measurements of: horizontal CDR, ICC stereoscopic (SS) = 0.7287; monoscopic (MS) = 0.5030; TC SS = 30%; MS = 32%; vertical CDR, ICC SS = 0.8439; MS = 0.7106; TC SS = 25%; MS = 31%; area CDR, ICC SS = 0.8392; MS = 0.6276; TC SS = 26%; MS = 32%; circumference CDR, ICC SS = 0.8433; MS = 0.6438, TC SS = 26%; MS = 31%. Systematic bias between observers and between methods was within acceptable limits. CONCLUSIONS: This study using a digital stereo camera indicates that there may be little benefit of stereoscopic imaging over monoscopic imaging despite demonstrating small but inconsistent differences between both observers and methods.

Adult↗

Optic disc morphometry with optical coherence tomography: comparison with planimetry of fundus photographs and influence of parapapillary atrophy and pigmentary conus.

PURPOSE: Optical coherence tomography (OCT) is an established method for visualising macular pathology and for measuring the thickness of parapapillary retinal nerve fibre layer. The purpose of the present study was to compare OCT measurements of the optic disc with those obtained by planimetry of fundus photographs and to investigate whether OCT measurements are influenced by the amount of parapapillary atrophy or pigmentary conus at the disc margin. MATERIALS AND METHODS: Eighty-two eyes of 41 randomly selected Asian-Indian subjects were included. The mean age was 44.2+/-14.3 years (mean+/-SD). All eyes underwent optic disc assessment by OCT (fast optical disc protocol) and digital 20 degree disc photos.. Planimetry of the discs were performed by outlining the disc and the cup. The amount of parapapillary atrophy (zone beta) was quantified as the number of clock-hours around the disc with adjacent parapapillary atrophy. The same procedure was performed to quantify the amount of pigmentary conus around the disc. RESULTS: Mean+/-SD disc size and mean+/-SD cup size in OCT measurements (2.37+/-0.51, 1.29+/-0.55) were significantly smaller than in photographic planimetry (2.83+/-0.62, 1.56+/-0.5: P<0.001, P<0.001). Optic discs with parapapillary atrophy (P=0.2) in their relative difference of disc sizes between OCT and planimetry. Similarly, optic discs with pigmentary conus (n=12) and discs without pigmentary conus (n=70) did not differ significantly (P=0.65). The relative difference in disc size between the two measurement modalities did not correlate with the amount of parapapillary atrophy (r=-0.17, P=0.29) or with the amount of pigmentary conus (r=-0.04, P=0.9). CONCLUSION: OCT analysis of the optic disc produces significantly smaller parameters, compared to the established method of optic disc planimetry. Neither presence, nor extent of parapapillary atrophy zone beta and pigmentary conus seems to produce a systematic error in measurements of disc size with the OCT.

Adolescent↗

The optic disc in glaucoma. IV: Optic disc evaluation in the ocular hypertensive patient.

A prospective study was carried out over a 3-year period on patients with one normotensive eye and one eye with ocular hypertension. A greater variability inthe responses to visual field testing was apparent in the hypertensive eye, but only on comparison of serial visual fields. Analysis of the stereo disc photographs demonstrated larger cup to disc ratios in the hypertensive eye without changes in the nerve fibre layer to equate with the visual field response. Stero disc photography is a quick and simple method of recording changes in the optic disc and should be considered in the follow-up of ocular hypertensive patients.

Glaucoma↗

Effect of optic disc size or age on evaluation of optic disc variables.

AIMS/BACKGROUND: It has been reported that the number of optic nerve fibres decrease with age, and the cup/disc (C/D) ratio increases as the optic disc size increases. Consequently, the normal value of the optic disc variables measured by an optic disc analyser may change according to the optic disc size or age. The effect of individual variations in optic disc size or age on interpretation of optic disc variables was investigated. METHODS: Topographic optic disc variables of 104 normal Asian adults of both sexes aged 40 to 68 were measured using a confocal scanning laser ophthalmoscope (TopSS, Laser Diagnostic Technologies, Inc). Fourteen variables were evaluated according to the optic disc size or age. Statistical analysis was done by regression analysis. RESULTS: With an increase in optic disc size, the increase in cup shape, effective area, 1/2 depth area, C/D ratio, neuroretinal rim area, volume above, volume below, and 1/2 depth volume were statistically significant (p < 0.05). However, contour variation, mean contour depth, average depth, maximum depth, average slope, and maximum slope were not affected (p > 0.1). Age did not have any significant influence on optic disc variables (p > 0.1). CONCLUSION: Optic disc size, but not age, should be considered in the interpretation of optic disc variables.

Adult↗

Agreement in assessing optic discs with a digital stereoscopic optic disc camera (Discam) and Heidelberg retina tomograph.

AIMS: To assess the intraobserver agreement, interobserver agreement, and the agreement between a digital stereo optic disc camera (Discam) and Heidelberg retina tomograph (HRT) in measuring area cup-disc ratio (ACDR) and radial cup-disc ratio (RCDR) by two observers. METHODS: The optic discs of 78 eyes of 39 people (17 cases of primary open angle glaucoma, eight normal tension glaucoma, two ocular hypertension, and 12 normal subjects) were imaged with Discam and HRT. Two observers independently drew the disc margins on the HRT mean topography images and the disc and cup margins on the Discam images. ACDR and the RCDR at various angles were measured with the two systems. Intraobserver agreement, interobserver agreement, and the agreement between the two systems were assessed by 95% tolerance limit of changes (TC) and intraclass correlation coefficient (ICC). RESULTS: Eight eyes were excluded due to poor image quality (six Discam and two HRT). 70 eyes were analysed. The intraobserver ACDR agreement was almost perfect in both systems (ICCs = 0.97 and 0.92, and TCs = 11.0% and 15.1% in HRT and Discam respectively). The interobserver ACDR agreement was almost perfect in HRT (ICC = 0.97) and substantial in Discam (ICC = 0.79), (TCs = 10.5% and 24.5% respectively). The ACDR agreement between the two systems was substantial in observer A (ICC = 0.67) and moderate in observer B (ICC = 0.53), (TCs = 24.8% and 46.7% respectively). The HRT measured the ACDR significantly larger than the Discam (p <0.001), and the differences were significantly larger in the glaucomatous group (p <0.001). RCDR agreement between the two systems was fair to substantial in observer A (ICC = 0.36 to 0.74) and slight to moderate in observer B (ICC = 0.12 to 0.45). Both observers achieved the best RCDR agreement between the two systems at the inferior optic disc position. CONCLUSION: There is almost perfect intraobserver agreement in each system. The interobserver agreement was better with the HRT than the Discam. There was substantial variation in ACDR and RCDR agreement between the two systems measured by the two observers. The variation in ACDR and RCDR measurements between the two systems may be too large for interchangeable use in a clinical setting.

Adult↗

Relationship between cup-disc ratio and optic disc diameter: the Blue Mountains Eye Study.

PURPOSE: To determine the effects of optic disc size on vertical cup-disc ratio in subjects free of glaucoma and other optic nerve disease. METHODS: Data were collected from 3654 people, 49 years of age of older, living in the Blue Mountains, west of Sydney (NSW, Australia). Examinations performed included subjective refraction and Zeiss colour stereo optic disc photographs. Eye and camera magnification effects were corrected. RESULTS: Mean vertical disc diameter was 1.51 mm (95% confidence interval (CI) 1.504-1.516 mm) and the mean vertical cup-disc ratio was 0.43 (95% CI 0.425-0.435). Both parameters were distributed unimodally. The cup-disc ratio was strongly associated with disc diameter. Controlling for other variables, cup-disc ratio increased 0.270 (95% CI 0.250-0.290) per mm increase in disc diameter. CONCLUSIONS: Vertical optic disc diameter and cup-disc ratio are distributed near normally in older Australians. Optic discs with larger vertical diameters have considerably greater vertical cup-disc ratios.

Anthropometry↗

Relationship of optic disc topography to optic nerve fiber number in glaucoma.

OBJECTIVE: To assess the relationship between in vivo measurements of optic disc topography and histomorphometric measurements of optic nerve fiber number in glaucoma. METHODS: Both eyes of 10 monkeys (Macaca fascicularis) with laser-induced glaucoma in the right eye were studied. Optic disc topography was measured in vivo with a confocal scanning laser ophthalmoscope. Histomorphometry was performed on optic nerve cross sections using bright-field microscopy with camera lucida. Nerve fiber density was estimated by unbiased random sampling. Nerve fiber number was estimated for each sector by multiplying nerve fiber density with neuroglial area. Nerve fiber count was compared with each of 13 global optic disc topographic parameters. RESULTS: For neuroretinal measurements in the glaucomatous eyes, rim area, retinal nerve fiber layer (RNFL) cross-sectional area, rim volume, and RNFL thickness correlated significantly with optic nerve fiber number. Differences in nerve fiber count between control and glaucomatous optic nerves showed the strongest correlation with differences in mean height contour; this was followed by RNFL cross-sectional area, RNFL thickness, rim volume, and differences in rim area. For cup measurements in the glaucomatous eyes, cup volume below reference, cup area, mean cup depth, the ratio of cup area to disc area, and cup shape correlated significantly with nerve fiber number. Differences in nerve fiber number between control and glaucomatous optic nerves showed the strongest correlation with differences in cup shape; this was followed by mean cup depth, cup volume below reference, the ratio of cup area to disc area, cup area, and differences in cup volume below surface. No association was found between optic nerve fiber number and optic disc area in glaucomatous eyes. CONCLUSIONS: In experimental glaucoma, most optic disc topography measures correlated significantly with optic nerve fiber number. The results of this histomorphometric study support the use of confocal scanning laser ophthalmoscopy to evaluate optic nerve damage in glaucoma.

Animals↗

Optic disc size and optic nerve damage in normal pressure glaucoma.

BACKGROUND: Recent reports indicate that eyes with normal pressure glaucoma have larger optic discs than eyes with primary open angle glaucoma or normal eyes. This study was performed to find whether, in normal pressure glaucoma, a large disc is associated with more optic nerve damage than a small disc. METHODS: Colour optic disc photographs of 74 patients with normal pressure glaucoma were assessed morphometrically. RESULTS: Taking the study group as a whole, the optic disc size decreased significantly (p = 0.04) with increasing visual field defect. In an intraindividual bilateral comparison, the side differences in the disc area of the right minus the left eye of the same individual were not significantly correlated with the side differences in the mean visual field defect. CONCLUSIONS: The results indicate that the eye with the larger optic disc, when compared with the contralateral eye with the smaller optic nerve head, showed neither a significantly more marked nor less pronounced glaucomatous optic nerve damage. It suggests that for a given patient the degree of glaucomatous optic nerve atrophy was not markedly associated with the optic disc size. The finding that patients with large visual field defects had smaller discs than patients with moderate perimetric loss may indicate that the results of previous cross sectional studies reporting on an unusually large disc size in normal pressure glaucoma may be due partially to selection.

Female↗

Reproducibility of evaluation of optic disc change for glaucoma with stereo optic disc photographs.

PURPOSE: To determine the reproducibility of the assessment for glaucomatous change in serial optic disc stereo-slides. DESIGN: Masked interobserver variability study. PARTICIPANTS: Serial optic disc stereo-slides from 40 patients. METHODS: Three independent ophthalmologists evaluated for change a set of two serial 20 degrees optic disc color stereo-slides of 40 patients. This test set was not from European Glaucoma Prevention Study (EGPS) patients. Each observer performed two evaluations at least 30 days apart and was masked from the temporal sequence of the slides and his or her previous evaluation. Each patient was graded as changed or stable by two-out-of-three agreement. A kappa statistic was used to calculate the intra- and interobserver reproducibility as well as the assignment reproducibility (first consensus versus second consensus). The same procedure was followed to test the reproducibility when another experienced ophthalmologist was added to one of the three reading centers. MAIN OUTCOME MEASURES: Reproducibility in evaluating glaucomatous optic disc change. RESULTS: The intraobserver reproducibility (95% confidence interval [CI]) in the evaluation of change ranged between 0.79 (0.45-1.14) and 1.00 (0.69-1.31). The interobserver reproducibility (95% CI) in the evaluation of change ranged between 0.45 (0.15-0.75) and 0.75 (0.44-1.06). The assignment reproducibility (first consensus versus second consensus in the evaluation of change) between the senior EGPS readers was 0.94 (0.63-1.25). The assignment reproducibility when another experienced ophthalmologist replaced one of the readers was 0.94 (0.63-1.25). CONCLUSIONS: The assignment reproducibility of three expert readers looking for glaucomatous change in serial optic disc stereo-slides was excellent. It remained so when one of the three experts was replaced by another experienced reader.

Double-Blind Method↗

Cupping of the optic disc in ischemic optic neuropathy.

Stereophotographs of the optic disc were reviewed in 78 patients with ischemic optic neuropathy (ION). Only 10% (6) of 61 nonarteritic (idiopathic) ION eyes developed optic disc cupping similar to that seen in glaucomatous eyes. Five of ten eyes with ION due to giant cell arteritis had cupping simulating glaucoma; however, two had elevated intraocular pressure, and the other three had large physiologic cups in the opposite eye. Optic disc pallor was proportionately more severe in ION eyes than in glaucomatous eyes of similar cup size. While there are similarities in the type of visual field loss in ION and glaucoma, the two disorders differ in the usual appearance of the disc after field loss has occurred and in the portion of the field most frequently affected. These observations suggest that if both disorders have an ischemic mechanism, there is a difference in the nature or distribution of the ischemia. There should be little difficulty under most circumstances in making the clinical differentiation between a disc that has suffered ION and a disc that has suffered pressure-induced damage, although occasional instances of ION may be classified as low-tension glaucoma on the basis of field loss and cupping without elevated intraocular pressure.

Acute Disease↗

Optic disc imaging by Heidelberg retinal tomogram in congenital optic disc anomaly.

We evaluated two cases of congenital optic disc anomaly with the Heidelberg Retinal Tomograph (HRT) that could be mistaken for glaucomatous optic disc. One was an optic disc coloboma with a visual field defect and the other had an optic disc pit without a visual field defect. HRT was abnormal only in the eye with optic disc pit with normal fields. While HRT can be a valuable adjunct to disc evaluation and follow-up, it cannot be used in isolation in the differentiation of abnormal from normal optic discs.

Adult↗