Improved visual acuity and recognition time in nystagmus patients following four-muscle recession or...

Many patients describe more rapid recognition of objects after surgical procedures for nystagmus; however, this "recognition time" is not reflected in the parameters typically studied in these patients. The purpose of this study is to assess the effect of nystagmus surgery on visual acuity and recognition time.

In this prospective, interventional, comparative case series, patients with nystagmus were divided into two groups. group A (n = 13) underwent four-muscle retroequatorial recession; group B (n = 8) underwent the Kestenbaum-Anderson procedure. Visual acuity, binocularity, and recognition time were assessed before and after surgery. Recognition time was measured in a routine examination setting using specially designed software that controlled the time of appearance of optotypes in 0.1 second increments.

A total of 21 patients were enrolled. The entire group experienced significant postoperative improvement in visual acuity (P = 0.002) and recognition time (P = 0.005). The mean improvement in recognition time was 0.3 seconds at maximum preoperative visual acuity level. A trend toward more improvement in group A than in group B was not statistically significant.

Both the four-muscle recession and the Kestenbaum-Anderson procedures resulted in a 1- to 2-line improvement in visual acuity and a 0.3 second improvement in optotype recognition time.