Long-Term Stability of Keratometry, Scheimpflug-Derived True Net Power, and Total Corneal Refractive Power After Primary Pterygium Excision.

Abstract

To evaluate long-term changes in mean keratometry, astigmatism, true net power (TNP), and total corneal refractive power (TCRP) of corneas after primary pterygium excision. This is a prospective observational series conducted at a tertiary teaching hospital eye center in Hong Kong. A total of 31 eyes of 31 patients with primary pterygium excision were included. Patients with recurrent or double-headed pterygia or a history of corneal scars from previous trauma, infection, or surgery were excluded. Data were collected prospectively at postoperative weeks 1, 4, 12, and month 18. Mean keratometry of the anterior cornea was 44.3 diopters (D) [95% confidence interval (CI): 43.6-44.9 D] at week 1, 44.3 D (95% CI: 43.6-44.9 D, standard error = 0.3) at week 4, 44.3 D (95% CI: 43.7-44.9 D) at week 12, and 44.1 D (95% CI: 43.5-44.7 D) at month 18. Mean astigmatism of the anterior cornea was 1.1 D (95% CI: 0.7-1.4 D), 1.0 D (95% CI: 0.7-1.3 D), 0.9 D (95% CI: 0.6-1.1 D), and 1.0 D (95% CI: 0.7-1.3 D) at postoperative 1, 4, 12 weeks, and 18 months, respectively. Mean keratometry, astigmatism of the anterior and posterior cornea, TNP and TCRP at 2.0-mm, 3.0-mm, 4.0-mm rings and zones remained unchanged on all follow-up visits (P = 1 for all comparisons). Keratometric values including TNP and TCRP were stable as soon as 1 week after pterygium excision. This information might help clinicians in planning subsequent intraocular surgery that requires biometric assessment for intraocular lens implantation.