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Biomedical subjects

Jost B Jonas

Publications and source records attributed to Jost B Jonas.

At least 73 records · Page 4Linked to original sources
PubMed2005

Intravitreal triamcinolone acetonide for treatment of intraocular oedematous and neovascular diseases.

Intravitreal triamcinolone acetonide (IVTA) has increasingly been applied as treatment for various intraocular neovascular and oedematous diseases. Comparing the various diseases with respect to effect and side-effects of the treatment, the best response in terms of gain in visual acuity (VA) has been achieved for intraretinal oedematous diseases such as diffuse diabetic macular oedema, branch retinal vein occlusion, central retinal vein occlusion and pseudophakic cystoid macular oedema. In eyes with various types of non-infectious uveitis, including acute or chronic sympathetic ophthalmia and Adamantiadis-Behcet's disease, VA increased and the degree of intraocular inflammation decreased. Some studies have suggested that intravitreal triamcinolone may be useful as angiostatic therapy in eyes with iris neovascularization and proliferative ischaemic retinopathies. Intravitreal triamcinolone may possibly be helpful as adjunct therapy for exudative age-related macular degeneration (AMD), particularly in combination with photodynamic therapy. In eyes with chronic, therapy-resistant ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure (IOP) and may stabilize the eye. The complications of intravitreal triamcinolone therapy include: secondary ocular hypertension in about 40% of the eyes injected; medically uncontrollable high IOP leading to antiglaucomatous surgery in about 1-2% of the eyes; posterior subcapsular cataract and nuclear cataract leading to cataract surgery in about 15-20% of elderly patients within 1 year of injection; postoperative infectious endophthalmitis occurring at a rate of about one per 1000; non-infectious endophthalmitis, perhaps due to a reaction to the solvent agent, and pseudo-endophthalmitis with triamcinolone acetonide crystals appearing in the anterior chamber. Intravitreal triamcinolone injection can be combined with other intraocular surgeries, including cataract surgery, particularly in eyes with iris neovascularization. Cataract surgery performed some months after the injection does not show a markedly elevated complication rate. The injection may be repeated if the resultant benefits decrease after the initial IVTA injection. In non-vitrectomized eyes, the duration of the effect and side-effects of a single intravitreal injection of triamcinolone is about 6-9 months for a dosage of about 20 mg, and about 2-4 months for a dosage of 4 mg. So far, it has remained unclear whether the solvent agent should be removed, and if so, how.

Choroidal Neovascularization↗
PubMed2005

Central corneal thickness correlated with glaucoma damage and rate of progression.

PURPOSE: To evaluate whether the amount of glaucomatous optic nerve damage at presentation of the patient and the rate of progression of glaucoma during follow-up are related to central corneal thickness. METHODS: The prospective observational clinical study included 861 eyes of 454 white subjects (239 normal eyes of 121 subjects, 250 ocular hypertensive eyes of 118 patients, 372 eyes of 215 patients with chronic open-angle glaucoma). For 567 eyes (304 patients) with ocular hypertension or chronic open-angle glaucoma, follow-up examinations were performed, with a mean follow-up time of 62.7 +/- 33.2 months (median, 60.8; range, 6.2-124.9). All patients underwent qualitative and morphometric evaluation of color stereo optic disc photographs and white-on-white visual field examination. Central corneal thickness was measured by corneal pachymetry. RESULTS: Central corneal thickness correlated significantly (P < 0.001) and positively with the area of the neuroretinal rim and negatively with the loss of visual field. Development or progression of glaucomatous visual field defects detected in 119 (21.0%) eyes was statistically independent of central corneal thickness, in univariate (P = 0.99) and multivariate Cox regression analyses (P = 0.19). CONCLUSIONS: At the time of patient referral, the amount of glaucomatous optic nerve damage correlated significantly with a thin central cornea. Progression of glaucomatous optic nerve neuropathy was independent of central corneal thickness, suggesting that central corneal thickness may not play a major role in the pathogenesis of progressive glaucomatous optic nerve damage.

Adolescent↗
PubMed2005

Central corneal thickness and thickness of the lamina cribrosa in human eyes.

PURPOSE: Since central corneal thickness may inversely influence the amount and rate of progression of glaucomatous optic nerve damage and because lamina cribrosa thickness may be of importance in susceptibility to glaucoma, it was the purpose of the present study to evaluate whether central corneal thickness is related to lamina cribrosa thickness. METHODS: The histomorphometric study included 111 enucleated nonglaucomatous eyes of 111 white subjects. On anterior-posterior histologic sections through the pupil and the central optic disc region, the thickness of the cornea, lamina cribrosa, and peripapillary sclera and the shortest distance between the intraocular space and the cerebrospinal fluid space were measured. Axial length ranged between 20 and 32 mm. RESULTS: Mean central corneal thickness (mean +/- SD: 616.6 +/- 108.3 microm) and mean central lamina cribrosa thickness (378.1 +/- 117.8 microm) were statistically independent of each other (P = 0.15; correlation coefficient, r = 0.14). In a similar manner, lamina cribrosa thickness at the optic disc border was statistically independent of central corneal thickness (P = 0.51; r = 0.06) and peripheral corneal thickness (P = 0.34; r = 0.09). In a parallel way, peripapillary scleral thickness (P = 0.84) and the shortest distance between the prelaminar space and cerebrospinal fluid space (P = 0.10) were statistically independent of central corneal thickness. CONCLUSIONS: In nonglaucomatous human globes, central corneal thickness may not correlate significantly with lamina cribrosa thickness, peripapillary scleral thickness, and shortest distance between intraocular space and cerebrospinal fluid space. Histologic artifact and sectioning methods could partially account for the lack of an association. The study results may suggest clinically that an assumed relationship between central corneal thickness and susceptibility to glaucoma cannot be explained by an anatomic correspondence between corneal thickness and histomorphometry of the optic nerve head.

Body Weights and Measures↗
PubMed2005

Correlation of confocal laser scanning tomography with planimetric photographic measurements of the optic disc in a normal South Indian population: the Vellore Eye Study.

PURPOSE: To compare the confocal laser tomographic scanning evaluation with photographic measurements of the optic nerve head in a South Indian population. METHODS: The prospective comparative clinical non-interventional epidemiologic study included 62 subjects (62 eyes) forming a population-based sample, selected randomly. Mean age was 47.2 +/- 8.9 years, mean refractive error measured was -0.17 +/- 1.10 diopter (range, - 4.50 to + 2.50 diopter). Confocal laser scanning tomographic images on Heidelberg Retina Tomograph (HRT) and colour optic disc photographs were morphometrically analysed and compared. Main outcome measures were morphologic optic disc parameters. RESULTS: The optic disc area measurements were significantly smaller (p < 0.001) in the HRT technique than in the photographic method. In contrast, the HRT as compared to the photographic measurements showed significantly (p < 0.001) larger values for the relative width and relative area of the neuroretinal rim. The differences in measurements between both methods were maximum in the nasal part (p < 0.001) of the optic disc and minimum in the temporal disc region. CONCLUSION: In normal eyes of South Indians, neuroretinal rim measurements by the HRT and expressed as percentage of disc size measurements are significantly larger than rim measurements on disc photographs.

Adult↗
PubMed2004

Bilateral optic neuropathy and unilateral tonic pupil associated with acute human herpesvirus 6 infection: a case report.

BACKGROUND: Human herpesvirus 6 (HHV-6), a widespread virus and causative agent of exanthema subitum in children, has been associated with a number of neurologic disorders including cranial nerve palsies, seizures, encephalitis, meningitis, and multiple sclerosis. PATIENT: A 31-year-old man presented with bilateral optic neuropathy, disc edema, and unilateral tonic pupil, which were found to be associated with acute HHV-6 infection. The patient had been suffering from juvenile diabetes for 5 years. One week after onset of intravenous antiviral therapy with foscarnet, disc edema subsided, and tonic pupil reaction was no longer detectable. CONCLUSIONS: HHV-6 infection may play a role as a causative agent in patients with optic neuropathy and tonic pupil.

Adult↗
PubMed2004

GEE approaches to marginal regression models for medical diagnostic tests.

The evaluation of a new medical diagnostic test may focus on two different scientific questions: (1). The new test may replace an existing one because of lower cost or higher validity. A related question would be the selection of the 'best' test(s) from a bundle of new or established measurements. (2). The new test may be used supplementary to other new or established procedures. In a recent publication, Leisenring and co-workers (Stat Med 1997; 16:1263-1281) developed a general marginal regression model for comparisons of diagnostic tests focussing on question (1). i.e. on the selection of the 'best' procedure. They applied the GEE approach of Liang and Zeger (Biometrika 1987; 73:13-22) to adjust for the correlation of data as a nuisance parameter. Using the general framework provided by Leisenring et al., we extend their approach and apply the GEE methodology to question (2). i.e. to the investigation of which of several diagnostic tests should be used supplementary to each other. We analyse data from a longitudinal study concerning pathogenesis, diagnosis and long-term course of the eye disease glaucoma. We find a dependence of the correlation structure of several diagnostic measurements on the severity of the disease. This result may be useful in clinical applications as regards the selection of subsets of diagnostic measurements in individual diagnostic processes but also in investigations concerning the relationship of the pathogenic process and the rationales of the different diagnostic procedures.

Biometry↗
PubMed2004

Intravitreal reinjection of triamcinolone for exudative age-related macular degeneration.

OBJECTIVE: To evaluate the outcome of repeated intravitreal injections of triamcinolone acetonide for the treatment of exudative age-related macular degeneration. METHODS: This prospective, comparative nonrandomized clinical interventional study included 13 patients with progressive exudative age-related macular degeneration with occult, or predominantly occult, subfoveal neovascularization. All patients had shown an increase or stabilization of visual acuity after a first intravitreal injection of 25 mg of triamcinolone acetonide. They received a second intravitreal injection of 25 mg of triamcinolone acetonide 3.1 to 18 months after the first injection. Mean +/- SD follow-up time after the second injection was 5.2 +/- 3.6 months (median, 5.3 months). A control group included 24 patients with exudative age-related macular degeneration who did not receive treatment for their maculopathy. The main outcome measures were visual acuity and intraocular pressure. RESULTS: In the study group, mean +/- SD visual acuity increased significantly (P =.005 and P =.003, respectively) from 0.17 +/- 0.11 to 0.32 +/- 0.26 and from 0.15 +/- 0.14 to 0.23 +/- 0.19, respectively, after the first and second injections. An increase in visual acuity was found for 10 patients (77%) after the first and second injections. In the control group, visual acuity did not vary significantly during follow-up (P =.81). The difference in change in visual acuity between the study group and control group was significant (P =.01 [Snellen lines] and P =.05 [logMAR units]). The peak in visual acuity and, in a chronologically parallel manner, the peak in intraocular pressure elevation occurred 2 to 5 months after each injection. CONCLUSIONS: Repeated intravitreal injection of 25 mg of triamcinolone acetonide may lead to an increase in visual acuity in patients with exudative age-related macular degeneration, with the peak in visual acuity and intraocular pressure elevation occurring about 2 to 5 months after each injection.

Aged↗
PubMed2004

Intraocular availability of triamcinolone acetonide after intravitreal injection.

BACKGROUND: To evaluate the intraocular concentration of triamcinolone acetonide after intravitreal injection. METHODS: The prospective clinical interventional case series study included 17 patients who had received a 20 to 25-mg intravitreal injection of triamcinolone acetonide as treatment for exudative age-related macular degeneration, diffuse diabetic macular edema, or retinal vein occlusions. During a secondary intraocular surgery taking place 4.1 weeks to 25.7 months after the intravitreal injection, aqueous humor samples were obtained. None of the eyes were vitrectomized. RESULTS: In the aqueous humor samples, triamcinolone acetonide was in low, but measurable, concentrations detected up to 1.5 years after the intravitreal injection. Concentrations found in samples obtained during the first 6 months, or 7 to 12 months, respectively, after the injection ranged between 3.0 microg/l and 436 microg/l, and between 0.0 microg/l and 11.2 microg/l, respectively. CONCLUSIONS: After injection of triamcinolone acetonide, triamcinolone can be present in measurable concentrations up to 1.5 years after the application.

Aqueous Humor↗
PubMed2004

Enlargement of parapapillary atrophy in follow-up of chronic open-angle glaucoma.

PURPOSE: To assess the frequency of an enlargement of parapapillary atrophy in follow-up of eyes with open-angle glaucoma. METHODS: Prospective observational longitudinal study. SETTING: Institutional. PATIENTS: The study included 978 eyes (511 Caucasian subjects) with open-angle glaucoma (n = 548; including 194 eyes with normal-pressure glaucoma), ocular hypertension (n = 289), or without optic nerve disease (n = 141). Highly myopic eyes with a myopic refractive error exceeding -8 diopters were excluded. Mean follow-up was 4.5 +/- 2.4 years (median, 3.8 years; range: 1.5 to 9.8 years). OBSERVATION PROCEDURES: Optic disk photographs taken annually. MAIN OUTCOME MEASURES: Two examiners compared optic disk slides for enlargement of parapapillary atrophy (zone beta) and for signs of progressive disk damage. RESULTS: An enlargement of parapapillary beta zone was detected in 16 eyes (1.6%) after 3.9 +/- 2.6 (0.6 to 9.1) years of follow-up. It was observed in 15 eyes (2.7%) with open-angle glaucoma, 1 eye (0.3%) with ocular hypertension, and in none of the normal eyes. After excluding eyes with a myopic refractive error exceeding -3 diopters, enlargement of beta zone was significantly more common in eyes with progressive glaucoma (5/81 or 6.2%) than in eyes with nonprogressive glaucoma (3/354 or 0.8%; P <.001). CONCLUSIONS: Parapapillary atrophy (zone beta) enlarges during follow-up of relatively few eyes with chronic open-angle glaucoma. In the refractive range above -3 diopters, enlargement of beta zone occurs significantly more frequently (P <.001) in progressive glaucoma than in nonprogressive glaucoma. In view of its low frequency, enlargement of beta zone may not be a very useful marker for glaucoma progression.

Adolescent↗
PubMed2004

Serum levels of triamcinolone acetonide after intravitreal injection.

PURPOSE: To evaluate serum levels of triamcinolone acetonide after intravitreal high-dose injection. DESIGN: Prospective, interventional case series study. METHODS: For 20 consecutive patients, venous blood samples were taken before and 13 +/- 19 days (range 4 to 92) after an intravitreal injection of 20 to 25 mg triamcinolone acetonide as treatment of edematous macular diseases. RESULTS: Serum levels of triamcinolone acetonide did not differ significantly (P =.174; t test for paired matches) preoperatively (0 microg/l) and postoperatively (0.065 microg/l +/- 0.21 microg/l). In 18 eyes (90%), triamcinolone acetonide could not be detected in serum samples. For two patients (10%), serum samples taken 5 days and 7 days after the injection, respectively, contained 0.5 microg/l triamcinolone acetonide and 0.8 microg/l triamcinolone acetonide, respectively. CONCLUSION: After an intravitreal high-dose injection of 20 to 25 mg triamcinolone acetonide, triamcinolone acetonide is not, or only marginally, detectable in serum samples obtained within 4 to 92 days after the injection.

Adult↗
PubMed2004

Duration of the effect of intravitreal triamcinolone acetonide as treatment for diffuse diabetic macular edema.

PURPOSE: To evaluate the duration of the effect of intravitreal triamcinolone acetonide on visual acuity in patients with diffuse diabetic macular edema. DESIGN: Clinical interventional case series. METHODS: Subjects were 31 patients (38 eyes) with diffuse diabetic macular edema who received an intravitreal injection of 20- to 25-mg triamcinolone acetonide. Mean follow-up time was 13.2 +/- 6.0 months (6.03-25.2 months). RESULTS: Visual acuity and intraocular pressure began to increase significantly (P =.003) within the first week, reaching a plateaulike maximum at 1 to 7 months postinjection, returning to baseline values 8 to 9 months postinjection. CONCLUSIONS: The effect of an intravitreal injection of approximately 20- to 25-mg triamcinolone acetonide in patients with diffuse diabetic macular edema lasts approximately 7 to 8 months. This information may be helpful in determining the optimal dosage of intravitreal triamcinolone acetonide for the treatment of diffuse diabetic macular edema.

Aged↗
PubMed2004

Optical coherence tomography and confocal scanning laser tomography for assessment of macular edema.

PURPOSE: To compare optical coherence tomography (OCT) and confocal scanning laser tomography (cSLT) for quantitative retinal thickness mapping of the macula and their ability to detect macular edema. DESIGN: Prospective, comparative, clinical observational study. METHODS: The study population of 138 eyes (97 patients) was divided into a study group consisting of 45 (32.6%) eyes with macular edema and a control group consisting of 93 (67.4%) eyes without macular edema. All patients underwent OCT and cSLT of the macula. Retinal thickness measurements obtained by OCT were compared with signal width and edema index, determined by cSLT. RESULTS: The OCT measurements and cSLT edema index were significantly (P <.001) correlated with each other. Correlation coefficients decreased (P <.001) with increasing diameter of the measurement circle. In the macular edema group, correlation coefficients were significantly (P <.001) higher than in the control group. To separate the study and control groups, receiver operator characteristic curves covered a larger area for OCT measurements than for cSLT measurements. Retinal thickness measurements and edema index correlate with visual acuity (correlation coefficient r = -.653 for OCT, r = -.608 for cSLT; P <.001). CONCLUSIONS: Macular edema can be quantitatively mapped by OCT and cSLT. The retinal thickness and edema index measurements correlate with visual acuity. The fast and standard examination modes of OCT give similar measurements. Both OCT and cSLT can differentiate between eyes with and without macular edema, with OCT showing a higher predictive value.

Aged↗
PubMed2004

Safety of intravitreal high-dose reinjections of triamcinolone acetonide.

PURPOSE: To report side effects after intravitreal high-dose reinjections of triamcinolone acetonide. DESIGN: Clinical interventional case series. METHODS: Forty-six patients (47 eyes) received at least two intravitreal injections of approximately 20 to 25 mg triamcinolone acetonide for treatment of diabetic macular edema (n = 6 eyes), exudative age-related macular degeneration (n = 23), and other diseases. Intervals between injections were 6.7 +/- 3.4 months, 8.0 +/- 4.6 months, and 10.2 months, respectively, before the second (n = 47 eyes), third (n = 9), and fourth (n = 2) injection. Mean follow-up was 20.7 +/- 8.9 months. RESULTS: After no reinjection were complications detected, other than those known to occur after a single intravitreal injection. After the first, second, and third injection, respectively, intraocular pressure remained normal in 24 (51%), 25 (53%), and 5 (56%) eyes. CONCLUSIONS: Intravitreal high-dosage reinjections of triamcinolone acetonide may be tolerated within a mean follow-up of approximately 21 months.

Glucocorticoids↗
PubMed2004

Inter-eye difference in diabetic macular edema after unilateral intravitreal injection of triamcinolone acetonide.

PURPOSE: To report on visual outcome of patients receiving intravitreal triamcinolone acetonide for treatment of diffuse diabetic macular edema. DESIGN: Prospective, comparative clinical interventional study. METHODS SETTING: Institutional. patient population: The study included 25 consecutive patients (50 eyes) with bilateral diabetic macular edema. Intervention procedure: Unilateral intravitreal injection of about 20 mg triamcinolone acetonide into the eye (study group) more severely affected by diabetic maculopathy. The contralateral eyes served as control group. Mean follow-up was 7.1 +/- 4.1 months. MAIN OUTCOME MEASURE: Visual acuity, intraocular pressure. RESULTS: In the study group, visual acuity increased significantly (P < or = .001) by 3.0 +/- 2.6 Snellen lines to a peak at two to six months after the injection, and decreased significantly (P = .001) towards the end of follow up. At the end of follow-up, visual acuity was higher, not significantly (P = .18) higher, than at baseline. An increase in visual acuity was found in 23 eyes (92%). In the control group, differences between visual acuity at baseline and at any of the re-examinations during follow-up were not significant (P > .10). In an intra-individual inter-eye comparison, gain in visual acuity was significantly (P < .05) higher in the injected eyes, for the measurements obtained up to four months after injection. CONCLUSIONS: Intravitreal triamcinolone acetonide may temporarily increase visual acuity in eyes with diabetic macular edema.

Aged↗
PubMed2004

Femtosecond laser LASIK flap preparation with conical incision and positional spikes.

PURPOSE: To describe the creation of corneal flaps for laser in situ keratomileusis (LASIK) with conical incisions and positional spikes that may increase postoperative rotational flap stability. SETTING: University Eye Department. METHODS: A corneal flap was prepared in 5 freshly enucleated porcine eyes using a femtosecond laser. In the first step, the flap bed with a diameter of 8.0 mm was created by an intrastromal incision running parallel to the corneal surface. In the second step, a posterior-anterior incision was created with a diameter of 8.0 mm at the level of the first incision and 7.0 mm at the corneal surface. In addition, a hinge and 3 spikes were prepared in the flap with corresponding notches in the surrounding tissue. RESULTS: In all eyes, the corneal flaps were prepared easily within 5 minutes. CONCLUSION: Femtosecond laser technology allowed a new type of LASIK flap formation with conical incisions and positional spikes.

Animals↗
PubMed2004

Phototoxic maculopathy after secondary intraocular lens implantation.

We report phototoxic maculopathy in 2 aphakic patients after secondary, scleral-sutured intraocular lens implantation. This rare complication may have been triggered by drugs that increased the photosensitivity of the tissue. Careful preoperative assessment is necessary to question the receipts of photosensitizing drugs and identify diseases that predispose patients to phototoxic injuries.

Aged↗