Jan Lestak

Changes in the Visual Cortex in Patients with High-Tension Glaucoma

Objective: To verify whether there is a correlation between visual field changes in high-tension glaucoma and changes in functional magnetic resonance of the visual cortex.Methods and patients: The authors examined nine patients with high-tension glaucoma in different stages by functional magnetic resonance (fMRI). The measurements were carried out on the Philips Achieva 3T TX MR system using the BOLD method. Optical stimulation was provided by a black and white checkerboard alternated with its negative image with a frequency of 2 Hz. Each measurement consisted of a sequence of five 30-second active phase periods and five resting periods of the same length. The obtained data were processed using SPM8 software.The complex ophthalmological examination was supplemented by the visual field in the rapid threshold program mode. The sum of sensitivities in the homolateral halves of the visual fields (ranging from 0-22 degrees) was compared to the extent of fMRI contralateral activity of the visual cortex. The group was compared to a group of eight healthy persons.Results: The obtained data were subjected to a statistical analysis (Non-parametric Spearman’s rank correlation coefficient) which showed a medium-grade correlation between the visual field changes and the changes in the visual cortex. R=0.667 (p<0.05), R=0.767 (p< 0.016) respectively.Conclusion: The authors proved that the progression of glaucoma disease corresponds to the functional changes in the cerebral cortex. The loss of ganglion cells of the striate cortex most probably results in the interconnection of the optical radiation with the functional ganglion cells of the temporal lobe.

Lateral Geniculate Nucleus in Hypertensive and Normotensive Glaucoma

Objective: To find whether changes in lateral geniculate nucleus (LGN) can be determined in vivo in hypertensive and normotensive glaucoma, and whether these changes correlate with the advancement of glaucoma disease.Methods and subjects: The authors examined two groups of patients, 9 patients with hypertensive glaucoma (HTG) and 9 patients with different stages of normotensive glaucoma (NTG). The diagnosis was based on a comprehensive ophthalmological examination. The results of both groups were compared with a group of 9 healthy subjects. A comprehensive ophthalmological examination was supplemented by examination of the visual field by means of a fast threshold program. The sum of sensitivity in the field of vision of homolateral halves (range 0 to 22 degrees) was compared with the size of contralateral corpus geniculatum laterale.Data collected from patients were compared with a group of nine healthy controls.We carried out MRI tests at 3-Tesla MRI scanner (Philips Achieva TX series release 3.2.1.1) using eight-channel sense head coil.Results: The measured values were subjected to statistical analysis using the Wilcoxon test and Spearman´s rank correlation coefficient.The authors proved reduction of LGN in both HTG and NTG (p=0.0000). The LGN reduction dependence on the stage of changes in visual fields was not statistically significant, in HTG for the right half of visual fields (RH VF) and the left LGN r=0.3255, p=0.3926, and for the left half of visual fields (LHVF) and the right LGN r=0.0033, p=0.9934. Similarly, in NTG, statistically significant correlation between RH VF and L LGN (r=0.0496, p=0.1745) and between LHVF and R LGN (r=0.5399, p=0.1335) was not found either. The authors demonstrated median duration dependence in hypertensive glaucoma treatment to the reduction of the LGN. R=-0.4908, p=0.179 for the right LGN and r=-0.7743, p=0.0143 for the left LGN.Conclusion: The reduction of LGN volume was proved both in patients with HTG and those with NTG.

Glaucoma and CNS. Comparison of fMRI results in high tension and normal tension glaucoma

AIM The objective of our work was to determine whether there is a difference in fMRI activation between patients with high tension glaucoma (HTG) and those with normal tension glaucoma (NTG). METHOD The sample consisted of eight patients with different stages of high tension glaucoma (3 females aged 41-65 and 5 males aged 40-73 years) and eight patients, also with different stages of normal tension glaucoma (6 females aged 53-70 and 2 males aged 40-52 years). The control group consisted of eight healthy subjects (3 females aged 23-46 and 5 males aged 23-65 years). All underwent complete ophthalmological examination, including visual field, colour vision, and electrophysiological functions. The results were compared with fMRI images after stimulation with black/white (BW) and blue/yellow (BY) checkerboard and then statistically processed. RESULTS The authors analyzed the results of published studies on high tension versus normal tension glaucoma in the images obtained by fMRI. They concluded on the basis of electrophysiological examinations that in high tension glaucoma, damage of the whole visual pathway occurs, starting from retinal ganglion cells up to the visual cortex. In normal tension glaucoma the response of ganglion cells is relatively normal. The pathology is found mainly in the visual pathway. For this reason, the authors carried out fMRI examinations in high tension glaucoma patients and patients with normal tension glaucoma. They found that advancing stages of high tension glaucoma cause progression of fMRI activity decrease. These relations were not observed in normal tension glaucoma cases. Similarly, in high tension glaucoma on fMRI examination to yellow/blue stimuli, the fMRI activity decrease was found to be greater than that to black/white stimulation. No similar effect was observed in normal tension glaucoma. CONCLUSION Normal tension glaucoma is, from the etiopathogenetical view, a different disease than high tension glaucoma.

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 bulls 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.

Comparison of b-Blockers and Prostaglandins Treatments in Primary Open-Angle Glaucoma

Objectives: Retrospective study to compare long-term effects of treatment with β-blockers and prostaglandins by assessing changes in visual fields. Methods and Patients: The group included 60 patients of approximately the same age (61 and 62 year olds), with the same changes in the visual field and the same central corneal thickness (556 μm), of which 30 were treated with β-blockers (18 females and 12 males) and 30 with prostaglandins (15 females and 15 males). There were no changes in medication in the course of treatment. During the follow-ups, the intraocular pressure was in the range 10 to 20 mmHg. We evaluated the changes in visual fields (pattern defects) at the last examination in 2012. The results were compared with findings in visual fields from 2005. No subject had any eye or systemic disease that could affect changes in the visual field. Corneal pachymetry was performed with a Tomey SP-100 ultrasound device. The visual field was examined by static perimetry using a MEDMONT M 700 device with a fast threshold glaucoma program. For comparison of the two groups treated with β-blockers and prostaglandins, we used the Mann-Whitney´s test. For comparison of treatment with β-blockers timolol, carteolol, betaxozol and vistagan, we used the non-parametric Kruskal-Wallis´ test, and subsequently to compare therapies with prostaglandins latanoprost and bimatoprost, we used the non-parametric two-sided Mann-Whitney´s test. Results: With statistical analysis, we have found neither changes between β-blockers and prostaglandins treatments (p=0.395 to 0.836) nor differences between different beta-blockers (p=0.495 to 0.576). Similarly, we found no statistically significant changes in either treatment with bimatoprost and latanoprost (0.575 to 0.965). Conclusion: Our results in the follow-up period of seven years showed no difference in the functional changing of visual field between the treatments with β-blockers and prostaglandins.

Schlemms Canal in OCT Images in Glaucoma Patients and Healthy Subjects

Objective: To determine by means of optical coherence tomography (OCT) whether there are changes in Schlemm’s canal (SC) in primary open-angle glaucoma (POAG) compared to healthy controls and whether the SC dimension varies during the treatment facilitating the outflow of intraocular humor through the uveoscleral pathway. Patients and methods of examination: 62 eyes of 31 POAG patients (22 women aged 27-83 and 9 men aged 26-80) were included in our set. The patients did not suffer from any other disease of the anterior segment of the eye. Intraocular pressure (IOP) was compensated by drug treatment and its values were in the range of 10-20 mmHg. The group was compared with 92 eyes of 46 healthy subjects (33 women aged 19-71 and 13 men aged 39-79). The SC of all of them was examined by anterior segment OCT-system with a Visante OCT Carl Zeiss Meditec Inc. in horizontal meridian No. 3 and 9. Results: The comparisons show that the values of right and left eyes of controls (p=0.474) and patients (p=0.143) did not differ. The re-external (0.00029), le-external (p=0.0031), re-internal (p=0.0015), le-internal (p=0.0002) SC dimensions between the control and patient groups differed significantly with the controls always having values significantly higher than the glaucoma patients. Treatment by prostaglandins and beta-blockers did not affect the size of the SC (p=0.23 to 0.95). Conclusion: In POAG eyes, SC size is smaller than in the eyes of the control group. Eyes on prostaglandin treatment had the same size than those on beta blockers.

Brain Activations in fMRI induced by Color Stimulation in Patients with Normotensive Glaucoma

Objective: The aim was to find, whether the activations in fMRI induced by black-white and yellow-blue stimulation in patients with normotensive glaucoma will be similar to those in patients with hypertensive glaucoma. Methods and subjects: The authors examined eight patients with various stages of normotensive glaucoma using functional magnetic resonance imaging (fMRI). The group was compared to a group of eight healthy persons. Measurements were performed on the Philips Achieva 3T TX MR system using the BOLD method. Optical stimulation was provided by black-white and yellow-blue checkered patterns alternated with their negatives with a frequency of 2 Hz. Each measurement consisted of a sequence with five 30-second periods of active phase and five resting periods of the same length. The obtained data were processed by SPM 8 software and general linear model (GLM). The difference in the number of activated voxels when using the black-white (BW) or yellow-blue (YB) stimulations was tested by a t-test. Statistical maps of BW>YB and BWYB differences of patients and controls were thresholded at the uncorrected threshold of p=0.001 and the number of voxels statistically compared by a t-test.Results: The mean value of the difference in the number of activated voxels when using the BW vs. YB stimulation was only 6% for the patients and 2% for the controls. Both the BW>YB and the BW<YB differences between the control group and the patients did not differ significantly: 318 voxels (p=0.098) and 23 voxels (p=0.799) respectively.Conclusion: The authors demonstrated that in the patients with normotensive glaucoma there are no corresponding functional changes in the cerebral cortex. Similarly to healthy individuals, the authors did not find differences in activation using BW and YB stimulation. Normotensive glaucoma pathogenetically behaves in a different way compared to hypertensive glaucoma.

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

Abstract 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.

High Tension Glaucoma and Normal Tension Glaucoma in Brain MRI

Introduction: Functional and structural changes of the central nervous system corresponding to high tension glaucoma (HTG) and normal tension glaucoma (NTG) were studied. Methods: In four patient groups, 80 eyes in 40 patients were examined. First group of 30 patients had three types of HTG: 10 with primary open angle glaucoma (POAG), 10 with pigmentary glaucoma (PG) and 10 of the monitored patients had pseudoexfoliative glaucoma (PEXG). The last patient group consisted of 10 patients with NTG. Comparison of the visual field, GDx, macular volume, PERG and PVEP was performed with the control group consisting of 40 eyes in 20 healthy subjects of comparable age and refraction. From the group of patients with HTG and NTG, we further studied functional brain changes using functional magnetic resonance imaging (fMRI). We examined 9 patients with HTG in different stages and 8 NTG patients (stage initial to medium) using fMRI with optical stimulation. Brain activations in both patient groups were compared with group of 8 healthy controls. Moreover, the size of lateral geniculate nucleus in these patients with HTG and different stages of NTG was compared. Results: Patients with PG had the highest degree of damage of the optic pathway. In the NTG, however, the ganglion cell layer was relatively normal but significant pathological changes were found in the optic pathway. Restriction in visual cortex activation indicates that the progression of high tension glaucoma corresponded to the functional changes in the cerebral cortex. Similar behavior was not observed in patients with NTG. We also proved the reduction of lateral geniculate nucleus (LGN) in both HTG and NTG. Conclusion: We conclude that in HTG of varied etiology, the damage occurs in the entire optic pathway. Based on our experience as well the medical literature, we think that HTG and NTG are different diseases and therefore their approach should be different.

The application of volumometry as an indication criterion in blow-out fractures - the first results from a prospective study

Backgroung and Aim. This work builds on our publication on the subject of creating a mathematical model for calculating the volume of proplaped soft tissue of the orbit in blow-out fractures, which aids us greatly in our choice of the most effective treatment immediately post-accident. PATIENTS AND METHODS In this prospective study (2014 - 2016) we treated 29 patients with blow-out fractures. 18 (62%) were treated conservatively and in 11 (38%) we proceeded surgically. We decided whether surgical or non-surgical therapy was appropriate on the basis of clinical ENT, eye examination and the total volume of prolapsed orbital soft tissue. All procedures were perfomed by the same operating team with a uniform subciliary approach and using PMR splints adapted to the correct size and shape. RESULTS On the basis of the mathematical model we reassessed findings in 2 patients: in one we decided against a surgical solution and in the other a surgical approach was indicated. All 18 patients treated conservatively, fully recovered and are free of diplopia. The 11 operated patients are also free of diplopia, only 1 patient (3%) displays clinically insignificant postoperative diplopia in extreme posisitons when looking upwards. CONCLUSION With proper selection of the optimal treatment, the rate of complete disappearance of diplopia and fully preserved motility of the eyeball ranges from 91 to 97%. Surgical treatment of orbital floor fractures is important, mainly to minimise persistent post-traumatic diplopia which significantly reduces a patients quality of life.