Abstract
Purpose: :
To study the effects of daily consumption of high dose (up to 1500 mg) oral niacin as a treatment for central retinal vein occlusion (CRVO).
Methods: :
Retrospective, community clinic based, two centre study. The records of 37 patients (37 eyes) with clinical characteristics of central or hemiretinal vein occlusion were reviewed. Complete pretreatment and posttreatment ophthalmological examinations and fluorescein angiography were performed in all cases. Patients were placed on a regimen of niacin (nicotinic acid) that was increased over 2–3 weeks to 1500 mg per day. Patients were monitored monthly utilizing visual acuity testing, color fundus photography, fluorescein angiography and optical coherence tomography. Monitoring of potential niacin side effects was performed in conjunction with an internist and included liver function testing. The primary outcome measure was improvement in visual acuity after at least sixty days of niacin intake.
Results: :
A total of thirty seven patients were studied for an average of 591.5 (range 27–2855 days). 56.7% of patients had visual acuities of 20/100 or better pre–treatment and 72.9% after treatment. The average number of lines gained was 1.9. With removal of the largest positive and negative outliers, the average number of lines gained was 2.13. Optical coherence tomography showed an average decrease in macular thickness of 264.92 microns. At the time of enrollment 27% of patients had visual acuities of ≥20/40, 51% between 20/50 and 20/200, and 22% < 20/200. These numbers are comparable to the median visual acuities upon enrollment in the Central Retinal Vein Occlusion Study (CVOS), of 29%, 43% and 28% respectively. Of CVOS patients with poor acuity at outset (< 20/200, n=201), 80% had a final visual acuity of < 20/200 at their final visit. The patients in this study with initial visual acuity < 20/200 (n=8), and treated with oral niacin, 25% of patients had a final visual acuity < 20/200 (n=2). In the CVOS, of patients with visual acuities ranging from 20/50 to 20/200, 37% had a decrease in vision to 20/200 or worse. In this study 5.5% (1/18) decreased to < 20/200. In this same sub group, 39% of patients vision increased to 20/40 or better (7/18), compared to 19% in the CVOS.
Conclusions: :
The visual acuity outcomes in this study compare favorably to those in the natural history group in the CVOS. Oral niacin would provide an inexpensive, non–invasive widely available method of treatment. Preliminary results are encouraging and a larger controlled study is warranted.
Keywords: vascular occlusion/vascular occlusive disease • ischemia