Laser interferometry: preoperative functional predictive value in retinal detachment.

PURPOSE: To determine the functional predictive value of laser interferometry (LI) in retinal detachment (RD). METHODS: Laser interferometry with test field diameters of 3 degrees and 8 degrees, both with and without light, was tested preoperatively in 42 eyes with rhegmatogenous RD that were candidates for scleral buckling. Snellen visual acuity (VA) and LI (four test fields) were tested preoperatively and postoperatively (1 week, and 1, 3, and 7 months). Sensitivity and specificity of LI to predict postoperative (7 months after surgery) VA improvement was calculated. Chi-square and Spearman correlation tests were used for statistical analysis. RESULTS: Statistically significant Snellen VA improvement (P = 0.02) was first found 7 months after surgery. Laser interferometry at 3 degrees without light showed statistically significant improvement 3 months after surgery (P = 0.05). Laser interferometry at 3 degrees without light showed the highest sensitivity (93%) and specificity (87%) values. The best correlation between preoperative LI and postoperative Snellen VA (7 months after surgery) was also found with 3 degrees LI without light (r = 0.71, P = 0.002). CONCLUSION: Laser interferometry (3 degrees without light) was useful in predicting VA improvement in cases with RD preoperatively and postoperatively. Laser interferometry at 3 degrees without light showed the best correlation with postoperative Snellen VA.