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Biomedical subjects

J B Jonas

Publications and source records attributed to J B Jonas.

At least 127 records · Page 7Linked to original sources
PubMed1999

Early versus late removal of retained intraocular foreign bodies.

PURPOSE: To compare early versus late removal of retained intraocular foreign bodies (IOFBs). METHODS: Sixty-two patients presenting with open-globe injuries due to lacerations by retained IOFBs were consecutively operated by the same surgeon between 1989 and 1997. Minimum follow-up was more than 3 months. In 43 patients, the IOFB was removed during the first 24 hours after the accident. In 19 patients, in whom the wound had been closed during a first operation, the IOFB was removed later than 24 hours after the accident. The study groups did not vary significantly in age, refractive error, type and size of IOFB, prevalence of traumatic cataract and peripheral or central corneal lacerations, or visual acuity on presentation. RESULTS: Endophthalmitis developed significantly more often in the late intervention group than in the early intervention group (3/19 [15.7%] versus 1/43 [2.3%]; P = 0.0467; chi-square test). Considering patients with retinal lesions due to the IOFB (n = 47), proliferative vitreoretinopathy occurred significantly more often in the late intervention group than in the early intervention group (6/13 [46.2%] versus 6/34 [17.6%]; P = 0.0449). CONCLUSIONS: Confirming previous reports, the results of the current study suggest that removing retained IOFBs within the first 24 hours after the injury may in some clinical situations reduce the risks of infectious endophthalmitis and proliferative vitreoretinopathy.

Adolescent↗
PubMed1999

Localised retinal nerve fibre layer defects in chronic experimental high pressure glaucoma in rhesus monkeys.

AIM: To evaluate prospectively in an experimental model of chronic high pressure glaucoma whether the concept of a mainly diffuse pattern of optic nerve damage holds true for high pressure glaucoma. METHODS: The study comprised nine eyes of nine rhesus monkeys (Macaca mulatta) with a mean age of 17.7 (SD 3.1) years (range 13-23 years). Experimental glaucoma was produced by multiple applications of argon laser to the trabecular meshwork. Applanation tonometry was regularly performed and fundus photographs, which were taken serially, were used for retinal nerve fibre layer (RNFL) assessment and morphometric optic disc analysis. Six monkeys, in which arterial hypertension and atherosclerosis had additionally been induced several years before elevation of intraocular pressure, did not show any sign of diffuse loss or localised defects of the RNFL before initiation of glaucoma. RESULTS: Compared with the same eyes at baseline, localised RNFL defects had developed in eight (89%) eyes. It included all three eyes (100%) of the monkeys without arterial hypertension/arteriosclerosis, and five of the six monkeys (83%) with arterial hypertension/arteriosclerosis. Four eyes had multiple localised RNFL defects. In all eyes, diffuse RNFL loss was additionally present. CONCLUSIONS: Besides diffuse loss of RNFL, localised RNFL defects were present in almost all eyes of monkeys with chronic experimental high pressure glaucoma. Challenging the concept that a mostly diffuse type of optic neuropathy occurs in high pressure glaucoma, the results suggest that, in high pressure glaucoma, at least a mixture of localised and diffuse pattern of optic nerve damage prevails.

Animals↗
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↗
PubMed1999

Preperimetric glaucoma diagnosis by confocal scanning laser tomography of the optic disc.

AIM: To evaluate the ability of confocal scanning laser tomography of the optic nerve head to detect glaucomatous optic nerve damage in ocular hypertensive eyes without visual field defects. METHODS: The study included 50 normal subjects, 61 glaucoma patients with glaucomatous changes in the optic disc and visual field, and 102 "preperimetric" patients with increased intraocular pressure, normal visual fields, and glaucomatous appearance of the optic disc as evaluated on colour stereo optic disc photographs. For all individuals, confocal scanning laser tomographs of the optic nerve head were taken using the Heidelberg retina tomograph (HRT; software 2.01). RESULTS: Almost all investigated HRT variables varied significantly (p < 0.05) between the normal eyes and preperimetric glaucoma eyes with pronounced overlap between the two study groups. Corresponding to the overlap, sensitivity and specificity values were relatively low when HRT variables were taken to differentiate between normal and preperimetric glaucoma eyes. At a given specificity of 95% highest sensitivities were found for the variables "rim area in the superior disc sector" (24.8%), "nerve fibre layer thickness in the inferior disc sector" (26.5%), and "rim volume in the superior disc sector" (25.5%). A multivariate approach increased sensitivity to 42.2% at a given specificity of 95%. For the glaucoma group highest sensitivity values were reached by rim volume in the superior disc sector (73.8%) and rim area (72.1%); the multivariate approach reached 83.6%. CONCLUSIONS: Owing to pronounced overlapping between the groups, confocal scanning laser tomography of the optic nerve head has relatively low diagnostic power to differentiate between normal eyes and preperimetric glaucoma eyes. One of the reasons may be the biological interindividual variability of quantitative optic disc variables.

Adult↗
PubMed1999

Agreement of measurement of parapapillary atrophy with confocal scanning laser ophthalmoscopy and planimetry of photographs.

PURPOSE: To evaluate whether parapapillary atrophy can be measured interactively using confocal scanning laser ophthalmoscopy. METHODS: For 36 patients with open-angle glaucoma or suspected of having glaucoma, confocal scanning laser ophthalmoscopy of the optic nerve head was performed using the Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Heidelberg, Germany). Alpha and beta zones of parapapillary atrophy were plotted independently by two examiners on HRT images before and after reviewing optic disc photographs. These data were compared with planimetric measurements obtained from analyzing the disc photographs. RESULTS: Before viewing the disc photographs, assessment using the HRT images correlated better with the beta zone than alpha zone planimetric measurements. If the HRT images were evaluated while simultaneously viewing disc photographs, correlation coefficients increased for both examiners 1 and 2. Interobserver and intraobserver reliability were 0.431 and 0.802, respectively, for alpha zone, and 0.882 and 0.948, respectively, for beta zone. CONCLUSION: Parapapillary atrophy can be estimated with confocal scanning laser ophthalmoscopy. Correlation with planimetric measurements is best if conventional optic disc photographs are simultaneously viewed. Intraobserver and interobserver reliability are higher for beta zone than for alpha zone.

Adult↗
PubMed1999

Optic cup deepening spatially correlated with optic nerve damage in focal normal-pressure glaucoma.

PURPOSE: To evaluate whether deepening of the optic cup in patients with focal normal-pressure glaucoma is correlated with the location of most marked loss of neuroretinal rim and visual field. METHODS: Using morphometric evaluation of color stereo optic disc photographs of 102 eyes of 65 patients with focal normal-pressure glaucoma, the superior half of the optic disc was compared with the inferior half. RESULTS: In eyes in which the optic cup was deepest in the inferior half of the disc, the most pronounced rim loss was located inferiorly significantly more often than superiorly, and the most marked visual field loss was located superiorly significantly more often than inferiorly. In eyes in which the optic cup was deepest in the superior half of the disc, the most pronounced rim loss was located superiorly significantly more often than inferiorly, and the most marked visual field loss was located inferiorly significantly more often than superiorly. Correspondingly, in eyes in which the most marked rim loss was located inferiorly, the deepest optic cup part was located inferiorly significantly more often than superiorly, and vice versa. CONCLUSION: In focal normal-pressure glaucoma, location of the most marked deepening of the optic cup is spatially correlated with the location of most pronounced neuroretinal rim loss and visual field damage. Because high-pressure glaucoma is typically associated with optic cup deepening and vascular optic nerve damage is associated with optic cup flattening, the spatial correlation between focal optic nerve damage and focal cup deepening may suggest the presence of a pathogenetic aspect in both high-pressure glaucoma and focal normal-pressure glaucoma.

Adult↗
PubMed1999

Polarimetric measurement of retinal nerve fiber layer thickness in glaucoma diagnosis.

PURPOSE: To evaluate reliability and diagnostic value of polarimetric measurements of the retinal nerve fiber layer (RNFL) thickness in the diagnosis of glaucoma. METHODS: The study included 81 eyes with perimetric glaucoma with glaucomatous changes of the optic disc and visual field defects; 52 eyes with preperimetric glaucoma with glaucomatous optic disc abnormalities and normal achromatic visual fields; and 70 normal eyes. For determination of reliability, four examiners repeated polarimetric measurements five times in ten normal subjects. RESULTS: The polarimetric variables were significantly correlated with increasing mean visual field defect and decreasing neuroretinal rim area. In correlation analyses with visual field defects, correlation coefficients were highest for the variable "superior/nasal ratio" and "the Number," a variable calculated by the neural network of the device. In correlations with neuroretinal rim area, correlation coefficients were highest for measurements of the inferior nerve fiber layer thickness. The preperimetric glaucoma group and the control group differed significantly in the variables "superior/nasal ratio" and "the Number" and, to a smaller degree, in the variables "superior/temporal ratio" and "superior/inferior ratio." The Number variable had a sensitivity of 82% and 58% at a predefined specificity of 80% in separating perimetric glaucoma patients and preperimetric glaucoma patients, respectively, from control subjects. Reproducibility of the polarimetric measurements ranged between 70% and 89%. CONCLUSION: Polarimetric measurements of the RNFL thickness can detect glaucomatous optic nerve damage in patients with visual field loss, and in some patients with preperimetric glaucomatous optic nerve damage. Considering the fast performance, easy handling, and low maintenance costs, RNFL polarimetry may be helpful in glaucoma diagnosis.

Adult↗
PubMed1998

Prevalence of diabetes mellitus and arterial hypertension in primary and secondary open-angle glaucomas.

BACKGROUND: This study was carried out to evaluate the prevalence of diabetes mellitus and arterial hypertension in the open-angle glaucomas. METHODS: The study consisted of 529 patients with primary open-angle glaucoma, including 170 patients with the age-related atrophic type and 22 patients with the highly myopic type; 152 patients with secondary open-angle glaucoma, including 85 patients with pseudoexfoliative glaucoma; 56 patients with the focal type of normal-pressure glaucoma; and 660 nonglaucomatous subjects in the control group. For all study groups, age-matched control groups were formed. RESULTS: Prevalence of diabetes mellitus and arterial hypertension did not vary significantly (P > 0.25; chi-square test) between the non-highly myopic primary open-angle glaucoma groups and the control groups. In highly myopic primary open-angle glaucoma, pseudoexfoliative glaucoma, and focal normal-pressure glaucoma, diabetes mellitus and arterial hypertension were less common; however, not in all cases was the difference from the control group significant. CONCLUSIONS: The results suggest that diabetes mellitus and arterial hypertension are not more common in patients with primary and secondary open-angle glaucomas than in age-matched nonglaucomatous subjects. In agreement with some previous epidemiologic studies, diabetes mellitus and arterial hypertension may not be positively associated with the primary or secondary open-angle glaucomas.

Aged↗
PubMed1998

Pressure-dependent neuroretinal rim loss in normal-pressure glaucoma.

PURPOSE: To evaluate whether, in normal-pressure glaucoma, the level of intraocular pressure is correlated with the degree of glaucomatous optic nerve damage. METHODS: Color stereo optic disk photographs of 98 eyes with the focal type of normal-pressure glaucoma, 17 eyes with the highly myopic type of normal-pressure glaucoma, and 36 eyes with the age-related atrophic type of primary open-angle glaucoma were morphometrically evaluated. RESULTS: In all three study groups, neuroretinal rim area declined significantly (P < .05) with increasing maximal intraocular pressure values. CONCLUSIONS: In different forms of open-angle glaucoma with normal intraocular pressure, eyes with relatively high intraocular pressure have more pronounced optic nerve damage than do eyes with relatively low intraocular pressure. This suggests a barotraumatic aspect in the pathogenesis of optic nerve damage in the normal-pressure glaucomas. It implies that therapeutically, an intraocular pressure in the low-normal range may less likely be associated with glaucoma damage than an intraocular pressure in the upper-normal range would be.

Aged↗
PubMed1998

Cataract surgery combined with transpupillary silicone oil removal through planned posterior capsulotomy.

OBJECTIVE: The purpose of the study was to evaluate transpupillary removal of silicone oil combined with cataract surgery in patients after pars plana vitrectomy. DESIGN: A prospective case-control study. PARTICIPANTS: Fifty consecutive patients underwent cataract surgery combined with removal of silicone oil, which had served as intraocular tamponade after pars plana vitrectomy. In 28 patients, silicone oil was removed through a planned posterior capsulotomy, and in 22 patients, silicone oil was removed through pars plana sclerotomies. All patients were operated on by the same surgeon. INTERVENTIONS: Pars plana vitrectomy, cataract surgery, and silicone oil removal were performed. MAIN OUTCOME MEASURES: Frequencies of retinal redetachment, secondary cataract, cystoid macular edema, and vitreous hemorrhage; visual acuity; intraocular pressure; and duration of surgery and visual rehabilitation were measured. RESULTS: Frequencies of postoperative vitreous hemorrhage (1 of 28 [4%] vs. 10 of 22 [45%]) and secondary cataract (0 of 28 vs. 6 of 22 [27%]) were significantly lower (P < 0.05; chi-square test), and duration of surgery and visual rehabilitation were significantly shorter (P < 0.01) for patients with transpupillary silicone oil removal than for patients with drainage of silicone oil through pars plana sclerotomies. Rate of retinal redetachment (4 of 28 [14%] vs. 4 of 22 [18%]), time of retinal redetachment (36 +/- 32 postoperative days vs. 54 +/- 65 days), frequency of dislocated intraocular lenses (1 of 28 vs. 0 of 22), and postoperative visual acuity did not vary significantly between the two groups. Persisting comeal endothelial decompensation and clinically significant cystoid macular edema due to cataract surgery were not observed in any patient. CONCLUSIONS: Silicone oil removal can be combined with cataract surgery. In view of a decreased frequency of postoperative vitreous hemorrhage, reduced rate of secondary cataract, and shorter duration of surgery and visual rehabilitation, transpupillary drainage of silicone oil through a planned posterior capsulotomy compares favorably with removal of silicone oil through pars plana sclerotomies. Retinal redetachment usually occurs within the first 3 postoperative months.

Adolescent↗
PubMed1998

[No effect of diabetes mellitus on the morphology of the optic nerve papilla in primary open angle glaucoma].

PURPOSE: To evaluate the effect of diabetes mellitus on the optic disc morphology in primary open-angle glaucoma. PATIENTS AND METHODS: Within a group of 364 patients with primary open-angle glaucoma, a subgroup of 52 patients with diabetes mellitus and a second subgroup of 312 patients without diabetes mellitus were compared with each other. Eyes with proliferative diabetic retinopathy had been excluded. Both subgroups were matched for age, gender, and refractive error. The optic disc was morphometrically evaluated using stereo disc photographs. RESULTS: The two subgroups did not vary significantly (p > 0.10) in mean size of the optic disc, neuroretinal rim and zones Alpha and Beta of the parapapillary chorioretinal atrophy, and frequencies of disc hemorrhages. CONCLUSIONS: Patients with or without diabetes mellitus do not differ significantly in the morphology of the optic disc. One may conclude that diabetes mellitus does not markedly influence planimetric assessed optic disc damage in patients with primary open-angle glaucoma, if eyes with proliferative diabetic retinopathy have been excluded.

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↗
PubMed1998

Neuroretinal rim width ratios in morphological glaucoma diagnosis.

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

Adolescent↗
PubMed1998

Histomorphometry of the optic disc in highly myopic eyes with absolute secondary angle closure glaucoma.

AIM: To evaluate histomorphometrically the optic nerve head in highly myopic eyes with absolute secondary angle closure glaucoma. METHODS: Optic disc sections of 16 highly myopic eyes with an axial length of more than 26 mm and of 19 eyes with an axial length of less than 26 mm were histomorphometrically evaluated. All eyes had been enucleated due to painful absolute secondary angle closure glaucoma. RESULTS: In the highly myopic eyes compared with the non-highly myopic eyes, mean optic disc diameter was significantly larger (mean 2.33 (SD 0.55) mm versus 1.77 (0.50) mm; p = 0.01), and the optic cup was significantly shallower (optic cup depth 0.34 (0.29) mm versus 0.63 (0.23) mm; p = 0.03). The peripapillary scleral ring was significantly broader (0.58 (0.65) mm versus 0.08 (0.06) mm; p = 0.001), and the beta zone (0.83 (0.74) mm versus 0.28 (0.25) mm; p = 0.006) of the parapapillary chorioretinal atrophy was significantly larger in the highly myopic eyes. CONCLUSIONS: The results of the present study agree with biomorphometric data of the optic nerve head in highly myopic eyes with glaucoma. In the highly myopic group, a markedly enlarged peripapillary scleral ring characterised by absence of Bruch's membrane and choriocapillaris contributes in addition to alpha and beta zone to the parapapillary atrophy.

Aged↗
PubMed1998

Comparison of measurements of neuroretinal rim area between confocal laser scanning tomography and planimetry of photographs.

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

Adult↗
PubMed1998

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.

Adult↗