Intrastromal corneal ring segment implantation for ectasia after refractive surgery

Area of Science:

• Ophthalmology
• Corneal Surgery
• Refractive Surgery Outcomes

Background:

• Ectasia is a rare but serious complication following refractive surgery like photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).
• This condition involves progressive corneal thinning and bulging, leading to visual impairment.

Purpose of the Study:

• To assess the clinical effectiveness of intrastromal corneal ring segment (ICRS) implantation in correcting ectasia.
• To evaluate visual acuity, refractive error, and corneal topography changes after ICRS implantation in patients with prior refractive surgery.

Main Methods:

• A retrospective case series included 41 eyes of 25 patients who underwent ICRS implantation for post-refractive surgery ectasia.
• Patients were categorized into two groups based on prior surgery: PRK (Group A) and LASIK (Group B).
• Corneal tunnels were created via mechanical dissection, and outcomes included uncorrected and best spectacle-corrected visual acuity, refraction, keratometry, and topography.

Main Results:

• Significant reductions in manifest astigmatism, keratometric astigmatism, and spherical equivalent were observed in both groups, particularly in the LASIK group.
• Mean manifest astigmatism decreased from -3.18 D to -1.77 D (p=0.000) and keratometric astigmatism from -4.80 D to -2.78 D (p=0.000) in the LASIK group.
• No significant differences were found between the PRK and LASIK groups regarding the overall outcomes, and no intraoperative or postoperative complications were reported.

Conclusions:

• Intrastromal corneal ring segment (ICRS) implantation is a viable and effective treatment for corneal ectasia after refractive surgery.
• ICRS implantation leads to significant improvements in visual acuity and a reduction in refractive cylinder.
• The procedure demonstrated a favorable safety profile with no observed complications.