Medical hypothesis discovery and innovation in ophthalmology

Abstract

Background: Astigmatism is the most prevalent refractive error among children and adults, and it can lead to visual impairment if left uncorrected. The management of compound hyperopic astigmatism is more challenging. This study presents the 12-month outcomes of toric implantable collamer lens (ICL) implantation in eyes with hyperopic astigmatism.
Methods: This interventional case series included patients with simple or compound hyperopic astigmatism who underwent toric ICL implantation. All eligible individuals underwent a detailed ocular examination. Uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively), intraocular pressure, and manifest and cycloplegic refraction results were documented. Pentacam corneal tomography was performed to assess the central corneal thickness, iridocorneal angle width, and anterior chamber depth. Endothelioscopy was performed to determine endothelial cell density. The ICL V4b model was implanted in all the included eyes. Safety and efficacy indices were calculated as postoperative CDVA/preoperative CDVA and postoperative UDVA/preoperative CDVA, respectively.
Results: Twenty-six eyes with low-grade simple or compound hyperopic astigmatism were included. All eyes experienced a significant improvement of four lines in postoperative UDVA (P < 0.001), and their postoperative CDVA remained stable at the 12-month follow-up (P > 0.05). The safety and efficacy indices were 1.0. None of the eyes lost two or more lines of CDVA; in 81% of the eyes, CDVA was unchanged, and the proportion of eyes with 20/30 or better postoperative UDVA was identical to that with 20/30 or better preoperative CDVA (81% for each). The mean manifest spherical equivalent at the 12-month postoperative visit had significantly improved (P < 0.001). The percentages of eyes with postoperative spherical equivalent within ± 0.50 D and ± 1.00 D were 81% and 96%, respectively. The postoperative refractive cylinder improved significantly (P < 0.05), and the percentage of eyes with refractive cylinder within ± 0.50 DC and ± 1.00 DC were 50% and 77%, respectively.
Conclusions: Our outcomes indicate that toric ICL implantation is safe and effective for managing low-grade simple or compound hyperopic astigmatism. The proportion of eyes with 20/30 or better postoperative UDVA was identical to that with a 20/30 or better preoperative CDVA. The manifest spherical equivalent and refractive cylinder were significantly reduced. No serious safety concerns were observed. Further prospective large-scale studies with a wide range of ages and grades of hyperopic astigmatism are required to verify these preliminary outcomes.