Single arcuate keratotomy based on front axial curvature and front elevation topographic maps to improve post-keratoplasty astigmatism

Abstract

To describe using single arcuate keratotomy (SAK) and compression sutures (CS) to improve two cases of post-keratoplasty irregular astigmatism. Patient A. A 26 year-old female with keratoconus developed left acute hydrops and underwent a penetrating keratoplasty. She subsequently developed cataract in that eye and uncorrected visual acuity (UCVA) was counting fingers. Patient B. A 57 year-old man had left penetrating keratoplasty for keratoconus 30 years previously. UCVA was 0.96 LogMAR. He could not achieve good vision with spectacles and found it increasingly difficult to tolerate contact lenses. Both patients had irregular graft astigmatism and underwent SAK and CS based on front axial curvature and front elevation topographic maps. Patient A had incisional refractive surgery combined with cataract removal and lens implantation. Patient A at 6 months postoperative (4 months post-removal of CS) visit attained visual acuity of 0.50 LogMAR unaided, improving to 0.10 LogMAR with −4.50DS/+7DC × 45°. Keratometric surgical effect (KSE) was +2.54DS/−4.69DC × 27° and the percentage reduction in astigmatic error was 57.8%. Patient B at 4 months postoperative (6 weeks post-removal of CS) visit attained unaided visual acuity of 0.42 LogMAR and 0.10 LogMAR with +0.50DS/−6.00DC × 175°. KSE was −4.94DS/10.27DC × 13° and the percentage reduction in astigmatic error was 65.3%. Single arcuate keratotomy with compression sutures based on front axial curvature and front elevation topographic maps can be a safe and effective treatment for post-keratoplasty irregular astigmatism.