Search PubMed⌕ Search

Biomedical subjects

K I Papastathopoulos

Publications and source records attributed to K I Papastathopoulos.

12 recordsLinked to original sources
PubMed2000

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.

Adolescent↗
PubMed1999

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.

Adult↗
PubMed1998

Fluorescein angiographic correlation of focal narrowing of retinal arterioles in glaucoma.

BACKGROUND: Recent studies have shown that focal narrowing of retinal arterioles in the parapapillary region occurs in eyes with optic neuropathies such as glaucoma. This study evaluated whether these vessel constrictions detected ophthalmoscopically have an equivalent in angiographic imaging of the fundus. METHODS: Fluorescein angiograms and colour wide angle fundus photographs of 33 patients with open angle glaucoma and 76 subjects with normal optic nerves were examined for focal narrowing of retinal arterioles. The angiograms had primarily been taken for other reasons such as age related macula degeneration. RESULTS: All focal narrowings of retinal arterioles detected on fundus photographs showed a localised constriction of vessel filling in the fluorescein angiograms. Degree of vessel narrowing on the fundus photographs and degree of constriction of the fluorescein vessel filling were significantly (p < 0.001) correlated with each other. CONCLUSIONS: Focal narrowing of retinal arterioles in the parapapillary region of eyes with optic neuropathies represents a real stenosis of the vessel lumen and is not due to an ophthalmoscopic artefact.

Aged↗
PubMed1997

Optic disk appearance in pseudoexfoliation syndrome.

PURPOSE: To evaluate the optic disk appearance in eyes with pseudoexfoliation syndrome. METHODS: Clinical data and color stereo optic disk photographs of 99 patients with pseudoexfoliative glaucoma and 42 nonglaucomatous subjects with pseudoexfoliation syndrome were compared with those of 658 patients with primary open-angle glaucoma and of 364 normal subjects. RESULTS: Mean optic disk area was significantly (P = .009) smaller in the pseudoexfoliative glaucomatous eyes (mean +/-SD, 2.52 +/- 0.49 mm2) than in the primary open-angle glaucoma eyes (2.71 +/- 0.63 mm2). Correspondingly, mean optic disk area was significantly (P = .04) smaller in the pseudoexfoliative nonglaucomatous eyes (2.48 +/- 0.52 mm2) compared with the normal eyes without pseudoexfoliation (2.67 +/- 0.67 mm2). Comparing the pseudoexfoliative subgroups with the nonpseudoexfoliative subgroups separately in the glaucomatous and the nonglaucomatous groups, no significant differences were found for neuroretinal rim area, size of alpha and beta zones of the parapapillary atrophy, and diameters of the retinal arterioles and venules at the disk border. In the glaucomatous group, the maximal intraocular pressure measurements were significantly (P < .001) higher in the pseudoexfoliative subgroup than in the subgroup with primary open-angle glaucoma. CONCLUSIONS: Except for a slightly smaller optic disk, eyes with pseudoexfoliative glaucoma and eyes with primary open-angle glaucoma do not vary significantly in their optic disk appearance despite significantly higher intraocular pressure peaks in pseudoexfoliative glaucoma. In eyes with pseudoexfoliation syndrome, a small optic disk does not predispose to glaucoma. In contrast with the anterior segment of the eye, the optic disk does not show pathognomonic features for pseudoexfoliation.

Aged↗
PubMed1997

[Ophthalmoscopic assessment of the size of the optic nerve papilla].

PURPOSE: To examine whether the optic disc size can be measured with common ophthalmoscopic lenses. PATIENTS AND METHODS: The horizontal and vertical disc diameters in 125 eyes of 65 patients were measured ophthalmoscopically using a commercial slit lamp with adjustable length of the beam and a Volk 60 diopters lens or a Volk Superfield lens. The refractive error of the subjects ranged between -7.25 D and +3.25 D (mean +/- S.D.: -0.34 +/- 1.77). Based on these measurements we calculated the optic disc area by applying a modified formula for an ellipse, where area = horizontal diameter x vertical diameter x pi/4. Additionally, we measured planimetrically the horizontal and vertical diameters of the optic disc on color stereo disc photographs after correcting the ocular and camera magnification according to Littmann's method. RESULTS: The values of the horizontal and vertical disc diameters evaluated on the photographs were by factors of 1.0 and 1.5 larger than those values measured with the Volk 60 D lens, and the Volk Superfield lens, respectively. Taking into account these constant linear correction factors, the optic disc diameters as measured by the Volk 60 D lens and the Volk Superfield lens varied by 0.11 +/- 0.09 mm (5.9 +/- 5.1%), and 0.11 +/- 0.09 mm (5.9 +/- 4.9%), respectively, from the values measured on the photographs. The error for the ophthalmoscopic measurement of the disc diameters decreased slightly with increasing disc size. With highly myopic eyes excluded, it was independent of the refractive error. CONCLUSION: For clinical purposes, the optic disc and other structures of the posterior fundus can be determined by ophthalmoscopy using a slit lamp and commonly used ophthalmoscopical lenses.

Adult↗
PubMed1996

Optic disc shape in glaucoma.

BACKGROUND: This study was performed to evaluate the shape of the optic disc in glaucoma. METHODS: We examined morphometrically color stereo optic disc photographs of patients with primary open-angle glaucoma (n = 804), secondary open-angle glaucoma (n = 130), normal-pressure glaucoma (n = 75), and high myopia combined with open-angle glaucoma (n = 33), visually normal subjects (n = 421), and nonglaucomatous subjects with high myopia (n = 36). The optic disc form was determined by the ratio of the minimal to the maximal disc diameter, the ratio of the horizontal to the vertical disc diameter, the angle between the maximal disc diameter and the horizontal, and a calculated form factor. RESULTS: In the normal eyes, the ratios and the form factor varied interindividually by less than 1:2. For a myopic refractive error of less than -8 D, the normal eyes and the glaucoma eyes did not differ significantly (P > 0.20) in their slightly vertically oval optic disc shape. Within the primary open-angle glaucoma group, the optic disc shape was not correlated with the neuroretinal rim area and the mean perimetric defect, either interindividually or in an intraindividual bilateral comparison. In the highly myopic group, the optic disc was significantly more ovally configurated, more obliquely orientated, and larger than in any other group. CONCLUSIONS: In contrast to the size of the optic nerve head, the shape of the optic disc does not show pronounced interindividual variability in eyes with a myopic refractive error of less than -8 D. With highly myopic eyes excluded, the optic disc shape as single variable is not markedly important for pathogenesis, early diagnosis and differential diagnosis of the glaucomas.

Diagnosis, Differential↗
PubMed1995

Pressure-dependent changes of the optic disk in primary open-angle glaucoma.

PURPOSE: This study was performed to differentiate glaucomatous changes of the optic disk that may be caused by increased intraocular pressure from those that may be pressure independent. METHODS: For 357 patients with primary open-angle glaucoma, the optic disk was morphometrically analyzed, and the intraocular pressure was measured in 24-hour profiles. RESULTS: By performing an intraindividual bilateral comparison, the differences in the maximal intraocular pressure values of the right eye minus the left eye of the same individual were significantly correlated with the differences in neuroretinal rim area and mean perimetric defect of the right eye minus the left eye. No significant correlations were found for the parapapillary atrophy. CONCLUSIONS: The results indicate that the eye with the higher pressure compared with the fellow eye with the lower pressure showed neither a significantly larger nor smaller parapapillary atrophy, which suggests that the papapapillary atrophy, compared with the neuroretinal rim area and the visual field defect, is less dependent or almost independent of an increased intraocular pressure.

Adolescent↗
PubMed1995

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↗
PubMed1995

Focal narrowing of retinal arterioles in optic nerve atrophy.

PURPOSE: To investigate the occurrence of focal narrowing of retinal arterioles in optic neuropathies. PATIENTS AND METHODS: Color stereo optic disc photographs of patients with primary open-angle glaucoma (n = 114), pseudoexfoliative glaucoma (n = 41), normal-pressure glaucoma (n = 54), ocular hypertension (n = 45), nonarteritic anterior ischemic optic neuropathy (n = 20), descending optic nerve atrophy (n = 60), and control subjects (n = 100) were morphometrically examined in a masked fashion. Focal narrowing of the retinal arterioles was estimated on a scale ranging from 0 to 6. RESULTS: In the control subjects, focal vessel narrowing was significantly and positively correlated with age (P < 0.05). It occurred significantly more often and was more pronounced in eyes with optic neuropathies than in the normal eyes when matched for age. In the eyes with glaucoma, focal narrowing of the arterioles was significantly (P < 0.01) correlated with the degree of optic nerve damage. In addition to a tendency toward a more marked vessel narrowing in the eyes with normal-pressure glaucoma, it did not vary significantly between the various glaucoma types and other optic neuropathies. It was independent of an enlarged parapapillary chorioretinal atrophy. DISCUSSION: Similar to general constriction, focal narrowing of the retinal arterioles is found more frequently and is more marked in eyes with glaucomatous or nonglaucomatous optic nerve damage than in normal eyes. It is correlated with the degree of optic nerve damage, and is typical for optic nerve atrophy, but not pathognomonic for glaucoma.

Adolescent↗
PubMed1995

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↗
PubMed1995

[Morphologic papillar signs of high pressure glaucoma].

PURPOSE: To examine the morphology of the optic disc in eyes with high-pressure open-angle glaucoma. MATERIAL AND METHODS: Using color stereo optic slides, 306 eyes of 183 patients with secondary open-angle glaucoma and 65 eyes of 35 patients with juvenile open-angle glaucoma (group I) were morphometrically examined and compared with 1119 eyes of 585 patients older than 40 years and suffering from with primary open-angle glaucoma (group II). RESULTS: The eyes of group I as compared to group II showed significantly (P < 0.0001) higher maximal intraocular pressure values and a significantly (P < 0.05) smaller optic disc and parapapillary atrophy. There was a tendency towards steeper and deeper cupping and a lower frequency of optic disc hemorrhages in group I than in group II. The optic disc shape did not vary significantly between the two groups. CONCLUSIONS: Minor parapapillary atrophy suggests high-pressure glaucoma. Barotrauma may be associated with a mostly diffuse damage of the optic nerve. The only slight enlargement of the parapapillary atrophy in the eyes with high-pressure glaucoma indicates that the development of the parapapillary atrophy may at least partially be independent of an elevation of intraocular pressure. The optic disc shape is not useful to identify eyes with high-pressure glaucoma.

Adult↗