Functional Magnetic Resonance Imaging in Patients with the Wet Form of Age-Related Macular Degeneration.

The study is designed to determine the relationship between the progress of the wet form of age-related macular degeneration and the activity of the visual cortex examined using functional magnetic resonance imaging. Ten patients with the wet form of age-related macular degeneration (9 female and 1 male) with a mean age of 74.7 years (58-85 years) at various stages of bilateral involvement of the disease were included. Patients did not suffer from any other ocular nor neurological disease. All the patients underwent functional magnetic resonance imaging examinations with stimulation of both eyes using a black-and-white checkerboard of size 25.8 × 16.2 degrees. The group was compared with a group of healthy subjects with an average age of 54.1 years (45-65 years). For statistical evaluation, the Mann-Whitney U test was used. Comparing the extent of visual cortex activations we found a statistically significant difference between both the groups (p = 0.0247). However, the dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant (p = 0.223). We conclude that in patients with the wet form of age-related macular degeneration, lower functional magnetic resonance imaging activity of the visual cortex was found compared with the control group of healthy subjects. Dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant.

Functional magnetic resonance imaging following epimacular and internal limiting membrane peeling - ipsilateral and contralateral findings.

PURPOSE: The purpose of this study was to find out whether peeling of the epimacular membrane (EMM) and internal limiting membrane (ILM) for symptomatic lamellar macular hole (LMH), causes impairment of the visual cortex. PATIENTS AND METHODS: This pilot study consisted of 8 eyes of 4 patients (2 females and 2 males), mean age 69.25 years (60-83 years), who underwent pars plana vitrectomy and EMM and ILM peeling in one eye for lamellar macular hole The second eye remained intact. The patients had no other ophthalmological or neurological disease. The control group consisted of 20 eyes of 10 healthy people (8 females and 2 males). mean age 52 years (34-65 years). In all of them, we performed functional magnetic resonance imaging (fMRI) of the brain to the visual paradigm (black and white chessboard of 25.8 x 16.2 degrees in size), as well as in patients 3-4 years following the surgery. For statistical processing, we used ANOVA and multiple regression for adjustment for the age of patients. RESULTS: In all patients, we recorded a decrease in fMRI activity of the brain following stimulation of the eye in which surgical intervention was performed. The fMRI values using ANOVA (without adjustment for age) were significantly different between groups (P<0.001). Following adjustment for age and the use of multiple regression, the fMRI values in the operated eyes were lower by 4142.39 vs the control eyes. In the group of unoperated eyes, the fMRI values were lower by 2807.39 vs the control eyes. Therefore, the results did not differ very much from the results without adjustment. CONCLUSION: In patients with symptomatic partial macular defect following EMM and ILM peeling, we recorded a significant decrease of the fMRI activity of the brain following stimulation of the operated eye, compared to the control group. We also found a decrease in activity in fMRI following stimulation of the contralateral eye. These findings lead us to the conclusion that EMM and ILM peeling may cause secondary impairment of the visual centres in the brain, not only on the side of the surgical intervention, but also on the contralateral side.

The function of the blood aqueous barrier in eyes with emulsified silicone oil.

PURPOSE: To evaluate the function of the blood aqueous barrier(BAB) in the eyes with silicone oil emulsification (SOE). METHODS: Protein concentrations, expressed in albumin equivalents,were determined in aqueous humor of the eyes with SOE in 11 consecutive patients by means of proton nuclear magnetic resonance (1H NMR) spectroscopy. Correlations with various clinical factors were studied. RESULTS: Normal function of the BAB (albumin equivalents 1mg/ml and less was found in 8 eyes (73%) independently on underlying disease, early postoperative reaction after pars plana vitrectomy with SO implantation, degree of SOE and late postoperative complications. Increased permeability of the BAB (albumin equivalents equal 2, 3 and 6.5 mg/ml) was found in 3 eyes (27%) with recent acute complication (retinal detachment after SO removal in 2 eyes, and secondary angle closure glaucoma in 1 eye). CONCLUSION: SOE in vivo was associated with increased permeability of the BAB in the minority of the eyes. Other factors should be studied to explain the variability of SOE. 1H NMR spectroscopy might be a valuable method for the study of SOE.

Optical coherence tomography in progressive cone dystrophy.

AIM: The aim of the study was to analyse different clinical pictures in patients with progressive cone dystrophy (PCD), to compare these with the results of optical coherence tomography (OCT) and to evaluate the benefits of this method for diagnosis. METHODS: The group consisted of 16 patients (32 eyes) with PCD. All patients were examined for visual acuity, colour sense and visual field. We performed biomicroscopic examination, photo-documentation, fluorescein angiography, electrophysiological tests and OCT. RESULTS: Using biomicroscopy and fluorescein angiography, we found changes in the retinal pigment epithelium ranging from barely detectable changes up to the typical bull's eye appearance. In all the eyes, OCT established statistically significant reduction in the thickness and structural changes in the neuroretina of the macula. Atrophy was evident especially in the outer nuclear layer, in the photoreceptor inner segment/outer segment junction and in the retinal pigment epithelium. Visual acuity was mainly dependent on the degree to which the continuity of the photoreceptor inner segment/outer segment junction layer was maintained. Eyes with better preserved neuroretinal structure in the fovea centralis had generally less reduced thickness of the retina and a better visual acuity. CONCLUSION: OCT specifies the quantitative and qualitative changes in the macula and may contribute significantly to the diagnosis of the progressive cone dystrophy, particularly in the early stages of the disease which is difficult to diagnose.