[The effect of keratoconus-associated refractive errors on the results of tomographic methods of studying the posterior structures of the eye]. / Vliyanie opticheskikh narushenii pri keratokonuse na rezul'taty tomograficheskikh metodov issledovaniya struktur zadnego segmenta glaza.

PURPOSE: The study assesses the potential influence of refractive errors in keratoconus (KC) on the results of tomographic methods of studying the structures of the posterior eye segment. MATERIAL AND METHODS: The study included 30 patients with bilateral stabilized KC of stages I-IV in classification by M. Amsler. Spherical and cylindrical components of refractions were determined using automatic refractometry, keratometry measurements - based on scanning keratotopography with Scheimpflug analyzer. Aberrometry was performed to evaluate corneal wave front according to the following parameters: root mean square for lower order aberrations (RMS LOA), root mean square for higher order aberrations (RMS HOA), vertical trefoil, vertical coma, horizontal coma and spherical aberrations. Optical coherence tomography (OCT) and laser confocal scanning ophthalmoscopy (HRT 3) data was used in morphometric analysis of the optic nerve head and peripapillary retina. The following morphometric parameters were analyzed: optic nerve head (ONH) area, optic disc cup area, optic disc cup volume, ratio of optic disc cup area to ONH area, neuroretinal rim area, neuroretinal rim volume, peripapillary retinal nerve fiber layer (RNFL) thickness. All studies were performed first without correction, and 30 minutes after installing customized scleral hard contact lenses (SHCL). RESULTS: Compensation of the refractive errors characteristic for KC was achieved as expected with contact correction. OCT revealed a general trend for reduction in the area and volume of the optic disc cupping, ratio of area to volume of the optic disc cupping, as well as an increase in other parameters. As such, with correction the values for area and volume of the neuroretinal rim according to OCT were 2.2 and 13%, HRT 3 - 18 and 51.6%; comparable increase in mean RNFL thickness - 2.8 and 28.5%, respectively (p<0.001). According to HRT 3 data, the area and volume of optic disc cupping statistically significantly decreased (by 21 and 28%, respectively), while OCT showed statistically significant decrease only in cupping area (by 5.7%). The ratio of cupping to ONH area decreased by 6.6 and 23% relative to the initial data obtained with OCT and HRT 3, respectively. Significant decrease in ONH area amid SHCL correction was observed only with HRT 3. The revealed changes in morphometric parameters were analyzed using the fundamental principles of physiological optics. Changes in interference pattern and, consequently, morphometric parameters of structures of the eye fundus in KC are of multifactorial nature, and are mostly associated with refractive and wave artefacts occurring when the rays pass through the irregular corneal surface and cannot be optically compensated by the device. The use of SHCL as means for making the optic system relatively regular can significantly decrease the artefacts in morphometric measurements. CONCLUSION: The results obtained in this study demonstrate the practicality of tomographic examination in KC with contact correction. The optimal choice is custom-fit SHCL, which along with proper correction of refractive errors also ensures stable position of the lens on the cornea. In standard examination specialists should take into account the «false¼ decrease in parameters of the peripapillary retinal nerve fiber layer and increase in ONH cupping.

[Centrally acting cholinomimetics in the complex therapy of progressive glaucomatous optic neuropathy].

UNLABELLED: Many factors exist that are associated with higher risk of glaucoma progression. Arterial hypotension, low perfusion pressure, vasospastic syndrome, diabetes mellitus, myopia, etc. increase the need for neuroprotective therapy, which is aimed at stabilizing the pathological process and creating favorable conditions for maintaining visual functions. The aim of this study was to assess the therapeutic efficacy of Gliatilin as part of the complex treatment of progressive glaucomatous optic neuropathy. MATERIAL AND METHODS: A total of 240 patients were randomly selected and divided into 2 groups, 120 patients each. Both groups were matched for age, somatic comorbidity, and the gravity of the glaucomatous process. Patient age averaged 71.3±1.6 years. Advanced glaucoma prevailed in both groups: 70.0 and 76.6% correspondingly. Neuroprotective therapy included drugs from different pharmacological classes so that different aspects of pathogenesis were addressed. Apart from that, patients from Group I first received intravenous Gliatilin (1000 mg/4ml, 12--15 doses) and then switched to oral (1 capsule b.i.d. for 4 months). All patients underwent standard ophthalmic examination and static perimetry. RESULTS: No adverse effects were observed over the first two weeks of Gliatilin course, during which the patients stayed in the hospital. IOP level was normal and stable. Although neuroprotective therapy does not directly affect IOP, stability of the latter describes the dynamics of the glaucomatous process. When assessing changes in visual functions, particular attention was paid to the central visual field, foveolar and total light sensitivity, peripheral visual field, and MD and PSD indices. All mean values showed a tendency toward improvement, more pronounced in the Gliatilin group. CONCLUSION: A complex therapy cannot be limited to a single drug only, and to make better decisions, one should consider not only ocular, but also general condition of the patient. Adjuvant Gliatilin in the complex therapy of progressive glaucoma is appropriate and efficient, especially in case of systemic atherosclerosis and cerebrovascular insufficiency. The frequency of stabilization therapy depends on the efficacy of the latest course and clinical manifestations of the glaucomatous process.