Abstract
Purpose :
Corneal degenerations, including Salzmann’s Nodular Degeneration (SND) and Peripheral Hypertrophic Subepithelial Corneal Degeneration (PHSCD), and surface alterations after pterygium surgery may cause peripheral corneal opacities with subsequent irregular astigmatism and visual reduction.
The aim of this prospective non randomized study is to evaluate the efficacy of a sectorial phototherapeutic keratectomy (PTK) in the treatment of peripheral corneal opacities.
Methods :
Eyes with visual acuity reduction and/or irregular astigmatism due to SND, PHSCD, or pterygium surgery, treated with sectorial PTK program by IRES technology were included in the study from September 2021 to November 2023. IRES laser (1,000 Hz, micrometric 0.6 mm dual gaussian spot laser) enables the customization of the ablation depth and three geometrical parameters (internal height of ablation from the corneal side, external height of ablation from the scleral side, and width of ablation) based on the shape of the peripheral corneal opacities. When necessary, manual removal was associated to PTK. LogMAR best corrected visual acuity (BCVA), topographic astigmatism, and superficial ocular discomfort with ocular surface disease index (OSDI) were assessed at 1, 6, 12, and 24 months.
Results :
A total of 28 eyes, (18 after pterygium surgery, 6 with SND, and 4 with PHSCD) of 28 patients were included in the study. Mean postoperative BCVA at 24 months (0.92 ± 0.11 LogMAR) showed a significant improvement compared to the preoperative BCVA (0.45 ± 0.17 LogMAR) (p<0.01). Mean postoperative topographic astigmatism at 24 months (0.63 ± 0.41 diopters) demonstrated a significant reduction compared to the preoperative value (1.36 ± 1.6 diopters) (p<0.01) (fig. 1). Mean postoperative OSDI score at 24 months (14.21 ± 5.87) showed a significant improvement compared with preoperative value (31.98 ± 16.46) (p<0.05). Manual removal was necessary only in 6 cases (21.4%).
Conclusions :
This study shows that the sectorial PTK is safe and effective in the treatment of sectorial corneal opacities (fig 2). The main advantages include a reduced laser energy and a minimized induction of inflammation which may be noteworthy if compared to the conventional 9 mm PTK treatment.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.