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Aim: to investigate the role of heterogeneous fibroblasts in the development of epiretinal membrane in eyes with modeled proliferative vitreoretinopathy., Material and Methods: The material for investigation were 6 eyes of 3 Chinchilla rabbits. Suspended fibroblasts (fibroblasts of the human skin - 200000 cells in 0.1 ml) were injected into the vitreous cavity via the pars plana. The animals were followed up for 1 month and then made out of the experiment. The eyes were enucleated and fixed in 10% neutral buffered formalin for routine histological examination. Microscopy was performed on the Leica system., Results: The main clinical and morphological criteria for a rabbit model of PVR induced by intravitreal injection of heterogenic fibroblasts have been established: epiretinal membrane formation, changes in intraocular structures (the retinal pigment epithelium and retina), and inflammation (due to transplantation immunity). Particularities of the epiretinal membrane development and the role of different intraocular structures have been described., Conclusion: The experimental fibroblastic model of PVR reproduces the final, fibrous, stage of PVR, which is significant for efficacy evaluation of antiproliferative drugs.

Aim: to evaluate the effect of dexamethasone intravitreal implant on the functional state of the eye in macular edema associated with central retinal vein occlusion., Material and Methods: The study included two groups of patients: group 1 (control group) - 8 patients (16 eyes) without ocular pathology and group 2 (study group) - 8 patients (8 eyes) with macular edema on the background of newly diagnosed thrombosis of the central retinal vein. All the patients from the study group underwent insertion of an intravitreal dexamethasone implant - Ozurdex. Best corrected visual acuity (BCVA) and retinal light sensitivity of the central visual field were followed up. The maximum follow-up period was 12 months., Results: In group 1 (controls), BCVA averaged 0.93±0.2 and retinal light sensitivity of the central visual field - 19.01±1.18 dB. In group 2, baseline BCVA and retinal light sensitivity were 0.08±0.02 and 4.23±0.2 dB, 1 month after Ozurdex implantation - 0.21±0.04 and 11.77±0.98 dB, at 12 months - 0.23±0.17 and 5.2±0.78 dB, respectively., Conclusion: Macular edema associated with central retinal vein thrombosis has a strong deteriorating effect on the functional state of the eye. The dexamethasone intravitreal implant in patients with postthrombotic macular edema contributes to functional improvement, including BCVA and light sensitivity of the central retina, over the first year. At that, different functional parameters show different dynamics after dexamethasone treatment. Light sensitivity values, in contrast to BCVA, change unevenly and significantly during the year. Intravitreal implantation of a dexamethasone implant in patients with postthrombotic macular edema is an effective symptomatic treatment of occlusive processes within the retinal venous system.

Aim: to describe baseline functional and anatomical parameters of the macular region and how they change under ranibizumab therapy depending on the type of diabetic macular edema (DME) determined with optical coherence tomography (OCT)., Material and Methods: The study included 100 patients (100 eyes) with diabetes mellitus and DME (38 men and 62 women) aged 61.9±5.6 years with the mean disease duration of 8.48 years. Basing on OCT findings, 4 groups (25 patients each) were formed: sponge-like DME, cystoid DME, DME with serous neuroepithelium detachment (NED), and mixed DME (cystoid DME and serous NED). All patients received 3 consecutive monthly injections of 0.5 mg ranibizumab. The relationship between anatomical, functional, and clinical parameters was analyzed., Results: The lowest visual acuity (VA) at baseline was found in patients with mixed DME (р<0.05). The greatest increase in VA after the 3 injections was noted in patients with sponge-like DME - 0.34±0.18. Retinal thickness was significantly lower (р<0.05) in sponge-like DME as compared to other groups both at baseline and after the treatment. Foveolar thickness decreased after the treatment in all groups, the effect being the most pronounced (the edema got reduced by 42.4%, р<0.05) in cystoid DME. The most significant reduction in macular volume (by 2.7 mm3) as well as its lowest absolute post-treatment values were reported for patients with cystoid edema (9.01 mm3, р<0.05 as compared to sponge-like and mixed DME). Correlation analysis revealed an evident relationship between the improvement in VA (ΔVA) and the decrease in macular volume (р<0.05). Of clinical parameters, only diabetes duration correlated with the extent of VA improvement (r=-0.3; p<0.05)., Conclusion: The effectiveness of intravitreal ranibizumab therapy for diffuse DME depends on the morphological type of macular edema by OCT. Moreover, it correlates with diabetes duration.

Aim: To evaluate functional and morphometric parameters of the central retina in patients with postocclusive macular edema treated with dexamethasone intravitreal implant injection., Material and Methods: We examined 5 patients (5 eyes) with newly diagnosed central retinal vein occlusion complicated by macular edema, including 4 men and 1 woman aged 55.8±3.65 years (experimental group). All the patients received a single injection of dexamethasone intravitreal implant. The maximum follow-up period was 12 months. The control group consisted of 5 presbiopic patients (10 eyes) aged 59.14±3.14 years., Results: One month after injection, the best corrected visual acuity (BCVA) and central retinal light sensitivity improved (from 0.09±0.03 to 0.19±0.05 and from 3.18±0.19 to 11.07±0.97 dB, correspondingly), while foveolar thickness decreased from 425.36±57.87 to 273.75±36.65 µm. One year after the treatment, BCVA remained high and averaged 0.21±0.14. The total light sensitivity also remained higher than that at baseline, however, decreased down to 4.8±0.76 dB. Optical coherence tomography showed some flatness of the fovea. Foveolar thickness appeared 1.5 times higher than that in the control group and 1.2 times higher than that at the 1-month follow-up after dexamethasone intravitreal implant injection. Over the whole follow-up period, IOP has never significantly exceeded the baseline, optical media remained clear., Conclusion: 1. Dexamethasone intravitreal implant has been shown effective in resolving postocclusive macular edema, improving visual functions, and increasing central retinal light sensitivity within the first month after injection. 2. Positive changes in morphometric parameters of the central retina induced by the injection involve inner segments of photoreceptors as well as the outer nuclear, outer plexiform and inner nuclear layers. The morphofunctional effect persists for no less than 12 months after injection. 3. Over the 1-year follow-up period, there has been no negative influence of the implant on either intraocular pressure level, or lens transparency.

Two cases of dexamethasone intravitreal implant (Ozurdex) use are reported. The drug promotes resolution of macular edema and ensures a long-term improvement of visual acuity. The latter may depend on such factors as the duration of the disease and localization of the occlusion. Application of Dexamethasone Intravitreal Implant provides new opportunities for the treatment of retinal vein occlusions.