Vol 22, No 2 (2022)

This review focuses on the therapeutic use of scleral lenses in the treatment of corneal pathology described in the international scientific literature.

The potential of scleral lenses in the treatment of pathology of the cornea and anterior segment of the eye has been studied since the late 1980s. The scleral lenses were actively used both in the treatment of corneal pathology and in the treatment of diseases of the anterior segment of the eye. The use of scleral lenses in the treatment of corneal pathology may promise an area for development for this treatment modality. Contrary to eye-drops, which remain on the ocular surface for a relatively short time, the scleral lenses provide a long-term hydration of the corneal epithelium and paralimbal conjunctiva. Tarsorrhaphy and other surgical interventions limit visual acuity and the field of vision and provide poor cosmetic results. The scleral lenses, however, can provide 2-in-1 therapy as they protect the ocular surface and, in case of epithelial roughness, may improve visual acuity in patients with ocular surface diseases. The ability of scleral lenses to provide a continuous hydration and protection of the ocular surface, allowing patients to maintain functional visual acuity, as well as their ability to be used in combination with other forms of therapy, makes them a valuable option for the treatment of severe ocular surface diseases. Incorporating scleral lenses into a combined, multidisciplinary approach to treatment can bring relief to patients without resorting to more invasive treatment options.

Our analysis identified only a few studies on the use of scleral lenses in the treatment of corneal pathology, which is likely due to the complexity of customization of their fit. This indicates the need for scientific research aimed at developing universal scleral lenses for the treatment of the cornea based on the criteria of the radius of curvature and the diameter of the cornea of a healthy eye.

Aim – to evaluate the specific features of the phacoemulsification and IOL implantation, as well as clinical and functional outcomes in patients with extremely elongated eyeball.

Clinical cases. Two female patients were observed. Patient 1: 67 years, diagnosed OU complicated cataract, high myopia, moderate amblyopia, primary open-angle glaucoma 3A. Visual acuity at admission vis OD = 0.001 n.c.; vis OS = 0.04 sph +2.00 D cyl -2.50 D ax 105° = 0.1. Patient 2: 68 years, diagnosed OU complicated cataract, high hyperopia, moderate amblyopia, primary open-angle glaucoma 1A, operated. Visual acuity at admission OD = 0.01 sph +11.00 D cyl +1.50 D ax 110° = 0.2; OS = 0.01 sph +11.00 D cyl +1.00 D ax 105 = 0.1. The phacoemulsification and implantation of Asphina IOL (Carl Zeiss Meditec AG, Germany) was performed in both patients: on the right eye of patient 1 and on the left eye of patient 2.

Results. A month after the operation, patient 1 had the uncorrected visual acuity Vis OD = 0.15, patient 2 had visual acuity Vis OS = 0.04 sph (+) 11.0 D = 0.2. Both patients were subjectively satisfied with the obtained visual functions.

Aim – to evaluate the efficacy and safety of micropulse transscleral cyclophotocoagulation (MP-TSCPC) modality in patients with early stages of glaucoma.

Material and methods. We examined 38 patients with early stage of primary open-angle uncompensated glaucoma (POAG) (17 patients with early stage, 18 patients with advanced stage) before and during 12 months after the MP-TSCPC treatment (SUPRA device 810, Quantel Medical, France) using the modified laser parameters - power W=2000 MW, 31.3 % - exposure cycle, total treatment time in 4 sectors - 200 s, the total energy 125 J. Fluence - 121.8 J/m².

Results. There were no complications after the procedure. In all patients, BCVA did not change during the observation period. A decrease in IOP was achieved in all patients. In 6 months of follow-up, the level of IOP remained stable and averaged 15.5 ± 4.5 mm Hd. Up to 12 months of follow-up, the hypotensive effect persisted up to 31% of the initial IOP, which averaged 16.0 ± 3.5 mm Hg. As a result, the persistent hypotensive effect helped to reduce the number of IOP-lowering medications in general, and to cancel them in 6 cases of 17 patients with early stage glaucoma.

Conclusion. MP-TSCPC modified protocol showed high efficiency (up to 31% of the initial value during the year) in reducing the intraocular pressure in patients with early stages of glaucoma. The use of MP-TSCPC in patients with high visual acuity demonstrated a good safety profile due to areactive postoperative period. Further monitoring of patients after MP-TSCPC is necessary to develop practical recommendations for indications and regimens.

Aim – to study the predominant localization of the eccentric fixation point in various types of macular pathology accompanied by the presence of a central scotoma.

Material and methods. 94 eyes (90 people) with various macular pathologies leading to loss of central vision were examined. Fixation was recorded on several devices: an MP-1 and MP-3 microperimeter (Nidek Technologies, Italy) and a MAIA microperimeter (СenterVue, USA). To visualize and register the presence of macular pathology, all patients underwent optical coherence tomography using a Stratus OCT 3000 device (Carl Zeiss Meditec Inc., USA) and Spectralis (Heidelberg Engineering, Germany).

Results. The study revealed that in most cases the preferred retinal locus is positioned in the upper and upper-left sector around scotoma, regardless of the etiology.

Conclusion. The preferred retinal locus in most cases is located in the upper-left area of the retina near the central scotoma, the projection of which is in the lower-left side of the visual field. Knowing the preferred retinal locus, a doctor can more successfully adapt a patient with the absence of central vision.

Aim – to study the proliferative effect of various concentrations of sulfated glycosaminoglycans (sGAG) on the culture of human corneal epithelial cells.

Material and methods. The study focused on the properties of a mixture of sGAG consisting of chondroitin-4-sulfate, chondroitin-6-sulfates and keratan sulfates obtained by isolation from the transparent unchanged stroma of the cornea of farm animals. The material for the in vitro study was the cells of the anterior epithelium of the human cornea.

In the experimental group No.1, a mixture of sGAG was added to the culture medium at a concentration of 0.1%, in the experimental group No.2 – at a concentration of 0.5%, in the experimental group No.3 – at a concentration of 1.0%. In the control group No.1, the medium was replaced without the addition of solutions, cell seeding was carried out similarly to seeding with experimental samples. The negative control group included the holes of the tablet without the addition of medium and solution.

Results. The highest levels of the cellular index (CI) were obtained in the experimental group No.3 (1.00% of sGAG) and amounted to 2.86± 0.11 (the total increase in indicators was 60.67%). In the experimental group No.2 (0.50% sGAG), the cellular index levels were 2.65±0.24 (the total increase in indicators was 52.29%), which was significantly different from the experimental group No.1 (0.10% sGAG) and the control group No.1, where these indicators were 2.54± 0.21 (35.81%) and 2.37±0.02 (25.39%) respectively.

Conclusion. The final CI indicators show that solutions of the sGAG mixture at concentrations of 0.5% and 1.0% have a more pronounced proliferative effect on human corneal epithelial cells in vitro from the range of concentrations under study. The results obtained open up the prospects for the use of sGAG in the development of new approaches to the treatment of patients undergoing a chronic drug therapy or patients with concomitant corneal diseases.

Aim – to develop a methodology for quantitative spectrophotometric analysis of carvedilol in the "Carvedilosol" medication based on aquacomplex of titanium glycerosolvate.

Material and methods. During the analysis we used the pharmaceutical substance "Carvedilol", gel "Tizol", ointment "Carvedilosol" consisting of 0.5% beta-blocker in titanium glycerohydrogel. The spectrophotometry was applied, registration of optical density and electron spectra was performed on spectrophotometer SF-2000. The following parameters were chosen for validation of the methodology: specificity, linearity, precision, correctness.

Results. It is reasonable to analyze Carvedilol at a wavelength of 243 nm with the limit of quantitative determination of 0.761 µg/ml. The results of the study showed that the weight of carvedilol in the ointment is within acceptable limits (0.0404-0.0548 g) according to the regulatory documentation for soft dosage forms (Order of the Ministry of Health of the Russian Federation No. 751n dated 26.10.2015).

Conclusion. Optimal conditions for the implementation of spectrophotometric method of analysis were selected for detection of the content of carvedilol in the ointment "Carvedilosol" with a relative error not exceeding ± 1.80 %.