Vinpocetine effect on the progression of atrophic form of age related macular degeneration

Abstract

Background: Age-Related Macular Degeneration (AMD) is the number one cause of blindness among people over the age of 50 in New Zealand. It is characterized by the loss of central vision due to gradual deterioration of macular function. Experimental data suggest that vinpocetine, a substance found naturally in the leaves of lesser periwinkle plant is both neuro-protective and anti-inflammatory, which makes it an attractive molecule to investigate in relation to the progression of atrophic changes seen in AMD patients. Objective: To review the knowledge and interest in supplement consumption of patients with AMD and to evaluate the effect of 10mg daily consumption of vinpocetine on AMD progression by monitoring different aspects of macular function in early diagnosed patients. Methods: Patients with AMD were invited to respond to a survey assessing the nutritional preferences of AMD patients (Part I). From those participating in the survey, 50 with early AMD in at least one eye were enrolled in a double-masked clinical trial (Part II). Those in the clinical trial were assigned to receive for 15 months a once daily pill to be taken orally, containing either 10mg vinpocetine or a placebo. Visual acuity, static contrast sensitivity, macular threshold perimetry, photostress recovery function, preferential hyperacuity perimetry and Amsler grid test were employed to monitor different aspects of macular function at the initial visit, then followed up every three months and thereafter for 15 months until the study ends. Results: Due to the thesis submission date, interim results have been obtained at the end of six months, approximately half way into the study. All 86 participants from Part I of the study maintained a healthy and balanced diet and were aware of nutritional supplements recommended for their condition. For Part II, the vinpocetine treated group showed a statistically significant better chance to have an improvement in static contrast sensitivity with an odd ratio (OR) equal to 5.74 times (95% CI=1.35-24.38; p=0.0178); This group had less often chance to lose photostress recovery time in six months period than the placebo group (OR=3.97; 95% CI=1.15-13.64; p=0.0287). There was no significant difference between the treatment and control groups for measures of visual acuity or central macular threshold sensitivity. Preferential Hyperacuity Perimetry and Amsler Grid tests were not useful for monitoring vision in this group of people with early AMD as no functional abnormalities were found in either group over the six months periods. Conclusions: This study will conclude in April, 2013 and more results will be emerging for calculation in order to get a more accurate analysis of effect of vinpocetine on AMD progression. From the six months results, we recommend that people aged 50 to 89 diagnosed with early age-related macular degeneration to take 10mg vinpocetine daily. We also recommend clinicians to use static contrast sensitivity and photostress vision recovery test to monitor macular function in early AMD cases.