Fundamentals of Presbyopia: visual processing and binocularity in its transformation.

BACKGROUND: The accommodation has considerable interactions with the pupil response, vergence response and binocularity. The transformation of visual reception processing and the changes of the binocular cooperation during the presbyopia development are still poorly studied. So, the regularities of visual system violation in the presbyopia formation need to be characterized. This study aims to reveal the transformation of visual reception processing and to determine the role of disturbances in binocular interactions in presbyopia formation. METHODS: This study included 60 people with emmetropic refraction, uncorrected distance visual acuity 1.0 or higher (decimal scale), normal color perception, without concomitant ophthalmopathology. The first group consisted of 30 people (from 18 to 27 years old) without presbyopia, the second cohort comprised 30 patients (from 45 to 55 years old) with presbyopia. The eyeball anatomy and optics were evaluated using ultrasound biomicroscopy, aberrometry, and pupillometry. The functional state of the visual system was investigated under monocular and binocular conditions. The registration of the disparate fusional reflex limits was performed by the original technic using a diploptic device which facilitated investigation of the binocular interaction under natural conditions without the accommodation response, but with the different vergence load. The disparate fusional reflex was analyzed using the proximal and distal fusion borders, and the convergence and divergence fusion borders. The calculation of the area of binocularity field was performed in cm2. RESULTS: The presbyopia formation is characterized by a change in an intraocular anatomy, optics, visual processing, and binocularity. The processes of binocular interaction inhibition make a significant contribution to the misalignment of the visual perception. The modification of the proximal, distal and convergence fusion borders was determined. It was revealed that 87% of the presbyopic patients had binocularity shortage, whereas the reduction of binocularity field area in extreme grade was seen in 6% of cases. CONCLUSIONS: The presbyopia formation is accompanied by a significant reorganization of the visual system activity and by the creation of the new visual processing interactions. These data may be useful in presbyopia surgery.

Intraocular Cytokines and Their Correlations with Clinical Parameters in Patients with Myopic Choroidal Neovascularization.

PURPOSE: To study cytokine levels in aqueous humor of patients with myopic choroidal neovascularization (mCNV), their correlations with each other and ocular parameters. METHODS: Ophthalmological examination and immunological study of aqueous humor with cytokine levels measurement (Bio-Plex™ Human Cytokine 27-Plex panel; Bio-Rad Laboratories, USA) were performed in 19 patients (19 eyes) with ranibizumab-treated mCNV and compared to 15 patients (15 eyes) with myopia without CNV. RESULTS: The levels of 10 cytokines were significantly different in patients with mCNV compared to the controls: the vascular endothelial growth factor (VEGF) level was 2 times lower (191.15 ± 142.30 and 320.06 ± 170.05 pg/mL, respectively), and the levels of PDGF, IL-2, IL-5, IL-13, IL-15, IL-17А, TNF-α, IL-8, and RANTES were elevated. Strong correlations between morphological and functional parameters and cytokines, including VEGF, were found. The VEGF level inversely correlated with the myopia degree and the cytokines IL-13, INF-γ, and RANTES. CONCLUSION: The decrease in VEGF levels accompanied by imbalance of other cytokines may suggest additional mCNV development pathways.

Intraocular cytokines in retinal vein occlusion and its relation to the efficiency of anti-vascular endothelial growth factor therapy.

PURPOSE: To analyze the change in the concentration of intraocular cytokines (ICs) in patients with retinal vein occlusion (RVO) before and after intravitreal ranibizumab therapy (IVR), and to find the correlations of IC with clinical activity of RVO and efficiency of treatment. MATERIALS AND METHODS: Forty-four patients aged 46-79 years old (mean age: 60.7 ± 7.5 years old) with RVO and macular edema (18 patients - with central RVO, 26 - with branch RVO) treated with IVR were included into the study. The concentrations of 27 cytokines were simultaneously measured in aqueous humor by flow fluorometry using Bio-Plex Pro Human Cytokine Panel, 27-Plex (Bio-Rad Laboratories, USA) at baseline and after the first IVR. Control group consisted of 20 age-matched patients. RESULTS: The levels of 11 cytokines (vascular endothelial growth factor [VEGF], receptor antagonist interleukin-1, interleukin-6 [IL-6], IL-8, IL-9, IL-10, IL-12r70, IL-13, IL-15, monocyte chemotactic protein-1 [MCP-1], regulated on activation, normal T expressed and secreted) were significantly (P < 0.05) different compared to control and significantly (P < 0.05) changed after IVR both in central and branch RVO. The patients were divided into two groups: the first -"effective" and the second - "partially effective" therapy. The second group characterized by the higher concentrations of VEGF, IL-8, IL-10, IL-17, and MCP-1 at baseline compared to the first group. CONCLUSION: The patients with RVO were characterized by the increased levels of VEGF and other pro- and anti-inflammatory cytokines and chemokines. Aqueous concentration of cytokines were different in patients with central and branch RVO and significantly changed after IVR. Insufficient response to IVR was associated with activation of immune-inflammatory processes.