Abstract
Purpose: :
To determine the effect of Neodymium:Yag laser capsulotomy on retinal straylight values in patients with posterior capsule opacification (PCO).
Methods: :
This prospective observational study comprised 36 eyes of 36 PCO patients (average age 73 years), scheduled to undergo Nd:Yag capsulotomy. Before and after Nd:Yag capsulotomy best corrected visual acuity (BCVA) (ETDRS chart), contrast sensitivity (CS) (Pelli-Robson) and retinal straylight (C-Quant instrument) were measured. The dutch version of the 25-item National Eye Institute's Visual Function Questionnaire (VFQ) and a newly developed 4-item photographic glare questionnaire were completed. The results of the PCO patients were compared to those of age-matched pseudophakic subjects without PCO (36 eyes).
Results: :
Before and after Nd:Yag capsulotomy, there was no significant correlation between the straylight parameter and BCVA (before capsulotomy r= .08, p> .05; after capsulotomy r= -.26, p> .05). The straylight parameter and CS showed a moderate correlation before capsulotomy (r= -.41, p< .05), but after capsulotomy there was no significant correlation (r= -.20, p> .05). BCVA, CS, straylight values and VFQ scores improved significantly after capsulotomy (mean improvements 0.20 log units, 0.18 log units, 0.11 log units and 63 points respectively, p-values < .0005). BCVA, CS, VFQ scores and glare scores in patients with a capsulotomy opening and control subjects did not significantly differ (p= .60 and p= .10 respectively). However, the mean level of intraocular straylight was higher in patients with a capsulotomy opening (1.19 log units) compared to control subjects (1.07 log units).
Conclusions: :
After capsulotomy BCVA, CS, straylight values and VFQ-scores significantly improved. No uniform relation between BCVA and retinal straylight exists. Straylight and BCVA must be considered as independent entry criteria for capsulotomy.
Keywords: posterior capsular opacification (PCO) • optical properties • laser