Myopic shift after Salzmann nodule excision

To quantify changes in manifest refractive error and mean keratometric power (Km) at 1 month and ≥12 months after Salzmann nodule excision.

Cornea service at Mayo Clinic, Rochester, MN.

Retrospective consecutive case series.

Changes in manifest refractive error (spherical equivalent), Km, and corrected distance visual acuity (CDVA) were compared for 73 eyes of 58 patients who underwent Salzmann nodule excision. Eyes with ocular comorbidities were excluded. Comparisons between preoperative and postoperative measurements were made by using generalized estimating equation models.

Mean patient age was 66 years, and 53 patients (91%) were female. Spherical equivalent manifest refractive error was -0.27 ± 2.66 diopters (D) before nodule excision and became more myopic (-1.10 ± 2.78 D) at 1 month after nodule excision (n = 69, P < .001) with no change at 12 months (n = 14, P = .13). A myopic shift ≥0.5 D occurred in 65% of eyes and ≥1.0 D in 36% of eyes. Km increased from 42.7 ± 2.11 D before nodule excision to 44.2 ± 1.82 D at 1 month after excision (n = 49, P < .001). CDVA improved from 0.18 ± 0.15 logMAR (Snellen equivalent 20/30) before nodule excision to 0.05 ± 0.09 logMAR (20/22, n = 69, P < .001) at 1 month after excision with no change at 12 months (n = 14, P = .73).

In addition to known changes in cylinder, Salzmann nodule excision is associated with a myopic shift in most eyes caused by corneal steepening. Patients should be counseled about the likelihood of refractive changes, and cataract surgery should be deferred until refractive stability is achieved.