Abstract
Purpose :
Salzmann nodule degeneration is associated with induced cylinder and irregular astigmatism that improve after nodule excision. The purpose of this study was to quantify changes in manifest refractive error and corneal curvature at 1 month and ≥12 months after Salzmann nodule excision.
Methods :
In a retrospective consecutive series, changes in manifest refractive error (spherical-equivalent), mean keratometric power (Km), and best-corrected visual acuity (BCVA) were compared for 73 eyes of 58 patients who underwent superficial keratectomy for Salzmann nodular degeneration by 2 surgeons at Mayo Clinic in Rochester, MN between 2014 and 2019. Eyes with ocular comorbidities that might affect visual acuity or keratometry were excluded. Comparisons between preoperative and postoperative measurements were made by using generalized estimating equation models.
Results :
Mean patient age was 66 years, and 68 patients (93%) were female. Spherical-equivalent manifest refractive error was -0.27 ± 2.66 D before nodule excision and became more myopic (-1.10 ± 2.78 D) at 1 month after nodule excision (n=69, p<0.01) with no change at 12 months (n=14, p=0.13). A myopic shift ≥0.5 D occurred in 65% of eyes, and >1.0 D in 36% of eyes. Km increased from 42.7 ± 2.1 D before nodule excision to 44.2 ± 1.8 D at 1 month after excision (n=49, p<0.01). BCVA improved from 0.18 ± 0.15 logMAR (Snellen equivalent 20/30) before nodule excision to 0.06 ± 0.15 logMAR (20/23, n=69, p<0.001) at 1 month after excision with no change at 12 months (n=14, p=0.73).
Conclusions :
In addition to the known change in cylinder, Salzmann nodule excision is associated with a clinically important myopic shift in most eyes caused by corneal steepening. Patients should be counseled about the likelihood of a myopic shift after nodule excision, and cataract surgery should be deferred to at least one month after nodule excision for keratometric stability.
This is a 2021 ARVO Annual Meeting abstract.