Contrast sensitivity and glare disability by halogen light after monofocaland multifocal lens implantation

Background-Standard examination of contrast sensitivity under conditions of glare disability is performed with incandescent light. A new halogen glare test that simulates glare as seen with oncoming vehicle headlights was use d to measure glare disability in patients implanted with multifocal and mon ofocal intraocular lenses (IOLs). Methods-28 patients with an average age of 69 years (SD 12 years) were impl anted with a monofocal IOL (SI-40NB, Allergan) and 28 patients with an aver age of 66 years (12 years) were implanted with a refractive multifocal IOL (Array-SA-40N, Allergan). All patients were followed for 5 months postopera tively. Contrast sensitivity at four spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) with and without a glare source were measured using the halogen glare test (CSV-1000 HGT). Statistical analysis was performed using the two sample Wilcoxon test. The local significance level was set at 0.05. Results-When tested at the lowest spatial frequency (3 cpd) without halogen glare, contrast sensitivity was lower in the multifocal group than in the monofocal group (p=0.0292). With additional glare, there was no difference between both groups. At all other spatial frequencies (6, 12, and 18 cpd), when tested without halogen glare (6 cpd, p=0.5250; 12 cpd, p=0.8483; 18 cp d, p=0.9496) and with moderate (3 cpd, p=0.7993; 6 cpd, p=0.4639; 12 cpd, p =0.7456; 18 cpd, p=1.0) and high halogen glare (3 cpd, p=0.1513; 6 cpd, p=0 .2016; 12 cpd, p=0.3069; 18 cpd, p=0.9933), there was no statistically sign ificant difference between groups. Patients in both groups of age 70 or old er had reduced contrast sensitivity without halogen glare and with moderate and strong glare. When monofocal and multifocal patients older than 70 yea rs of age were analysed separately, there was no statistically significant difference in contrast sensitivity with and without glare. Astigmatism >1 d ioptre had no significant influence on contrast sensitivity and glare disab ility when monofocal and multifocal eyes were compared. Conclusion-Reduced contrast sensitivity was found in the multifocal group o nly at the lowest spatial frequency without halogen glare. The monofocal an d multifocal groups had no statistically significant differences in contras t sensitivity with moderate and strong glare. These results suggest no diff erence in glare disability induced by halogen light similar to oncoming veh icle headlights for patients implanted with monofocal and multifocal IOLs.