Mitochondria-targeted cationic plastoquinone derivative SkQ1 (10-(6'-plastoquinonyl) decyltriphenylphosphonium) has been investigated as a potential tool for treating a number of ROS-related ocular diseases. In OXYS rats suffering from a ROS-induced progeria, very small amounts of SkQ1 (50 nmol/kg per day) added to food were found to prevent development of age-induced cataract and retinopathies of the eye, lipid peroxidation and protein carbonylation in skeletal muscles, as well as a decrease in bone mineralization. Instillation of drops of 250 nM SkQ1 reversed cataract and retinopathies in 3-12-month-old (but not in 24-month-old) OXYS rats. In rabbits, experimental uveitis and glaucoma were induced by immunization with arrestin and injections of hydroxypropyl methyl cellulose to the eye anterior sector, respectively. Uveitis was found to be prevented or reversed by instillation of 250 nM SkQ1 drops (four drops per day). Development of glaucoma was retarded by drops of 5 microM SkQ1 (one drop daily). SkQ1 was tested in veterinarian practice. A totally of 271 animals (dogs, cats, and horses) suffering from retinopathies, uveitis, conjunctivitis, and cornea diseases were treated with drops of 250 nM SkQ1. In 242 cases, positive therapeutic effect was obvious. Among animals suffering from retinopathies, 89 were blind. In 67 cases, vision returned after SkQ1 treatment. In ex vivo studies of cultivated posterior retina sector, it was found that 20 nM SkQ1 strongly decreased macrophagal transformation of the retinal pigmented epithelial cells, an effect which might explain some of the above SkQ1 activities. It is concluded that low concentrations of SkQ1 are promising in treating retinopathies, cataract, uveitis, glaucoma, and some other ocular diseases.

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We studied the development of retinal ischemia in rat eye after laser coagulation of blood vessels. Typical signs of ischemia manifested in the retina after 24 h: development of stable retinal edema, decrease in the b/a index (ratio of the electroretinogram b and a-wave amplitudes) to 1-2 units, pronounced disorders in the retinal microcirculation system, leading to ischemia of the inner layers of the retina. The proposed model is convenient for studies of the development of acute retinal ischemia, is easily realized, and reproduces some acute ischemic diseases of the retina.

Purpose To evaluate the association between functional and hemodynamic alterations of the retina in diabetes mellitus (DM) without retinopathy (NDR). Methods 15 patients (63±6.3 years) with DM type II (duration 6±3.5years) and NDR, and 40 age matched controls were examined. Color Doppler Imaging (CDI) was conducted to visualize blood flow in ophthalmic artery (OA), central retinal artery (CRA), medial and lateral posterior ciliary arteries brevis (PCAB). Photopic and scotopic flicker ERGs (p‐FERG and s‐FERG) were recorded at 8.3, 10, 12, 30 Hz flickering. Results In NDR, the increase of the blood flow peak systolic velocity (V syst) and end diastolic velocity (Vdiast) was noted in AO. The most significant changes in blood flow were observed in CRA and PCAB. A reliable correlations were shown between Vdiast, the resistance index RI in CRA and insulin levels (r=0.64), serum C‐peptide (r=0.60) and the index of insulin resistance IR (r=0.65); between Vdiast, RI in PCAB and insulin levels, the C‐peptide level and IR (r=0.59, 0.56, 0.59, respectively). The amplitude of light and dark adapted FERG at 8.3‐12 Hz declined in more than 60% eyes up to 69‐80%. The p‐FERGs at 24 and 30 Hz did not differ from the control; but we found a sharp increase in s‐FERG (155.5±15.3 ‐ 319.9±21.4% for 24 ‐ 30 Hz respectively). Significant correlation was shown between the 10Hz‐FERG amplitude (but not the 24Hz or 30Hz‐FERG) and Vdiast in CRA and PCAB (r=0.51; r=0.50). Conclusion There is a significant relationship between the retina hemodynamics and physiological effects of insulin, leading to metabolic disorders. Signs of blood flow deficiency in CRA and PCAB in NDR correlated with an early alteration in the photoreceptor function.

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