Topography-guided photorefractive keratectomy in the treatment of corneal scarring
Reviewed by Inderpaul S Sian

This study reports the outcome of topography-guided photorefractive keratectomy (TG-PRK) in the treatment of patients with corneal scarring. A retrospective case series including six eyes of six patients with corneal scarring and irregular astigmatism who underwent topography guided PRK. The etiologies for scarring were; infectious corneal ulcers, foreign body trauma, LASIK flap buttonhole, and lamellar keratoplasties performed to correct corneal perforation secondary to corneal melting. Outcome measures included corrected distance visual acuity, uncorrected distance visual acuity, manifest refraction, and corneal regularity on topography maps. The average age of study participant was 56.5 ± 19.6 years and average follow up time was 14.8 ± 6.1 months. Three patients had corneal scarring with cataract and underwent TG-PRK to achieve sufficient regularisation of corneal astigmatism to enable the implantation of a toric intraocular lens (IOL). The three remaining patients had TG-PRK performed to improve visual acuity, and all had improvement in uncorrected (improvement between one and three Snellen lines) and corrected (improvement between two and three Snellen lines) distance visual acuity. There were no intraoperative or postoperative complications and no loss of visual acuity. This study concludes that the use of TG-PRK for corneal scarring may improve visual acuity in selected cases, obviate the need for keratoplasty in some cases, and facilitate toric IOL implantation. The limitations of this study are in its small sample size and its lack of data on the change in optical aberrations post PRK. 

Topography-guided photorefractive keratectomy in the treatment of corneal scarring.
Sorkin N, Einan-Lifshitz A, Boutin T, et al.
JOURNAL OF REFRACTIVE SURGERY
2017;33(9):639-44.