Three-Year Outcomes of Implantable Collamer Lens Followed by Excimer Laser Enhancement ("Bioptics") in the Treatment of High Myopic Astigmatism

Abstract

Purpose: Describe three-year outcomes of spherical implantable Collamer lens (ICL) followed by excimer laser enhancement (bioptics) in eyes with high myopic astigmatism.

Patients and methods: Retrospective case series of thirty-four cases that underwent bioptics enhancement at the Johns Hopkins Wilmer Eye Institute. All eyes had a preoperative sphere of -6.00 D or more with a cylinder of at least 2.00 D. Uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest spherical equivalent refraction (MSE), ICL vault measurements and central corneal thickness (CCT) were collected. Endothelial cell counts (ECC), root mean square (RMS) of higher order aberrations (HOAs), adverse events and subsequent surgeries were also assessed.

Results: All patients had a minimum follow-up of 3 years. Preoperative UDVA was 2.29 ± 0.46 logMAR and improved to 0.03 ± 0.23 logMAR at 3 years (p<0.05). MSE was -12.30 ± 4.05 preoperatively and changed to -0.21 ± 0.46 at 3 years (p<0.05). The efficacy and safety indices were 1.28 ± 0.32 and 1.47 ± 0.27 at 3 years post-enhancement. HOA did not significantly change throughout the follow-up (p<0.05). Endothelial cell loss at 12 months was calculated at 5.7%. Two eyes required ICL exchange due to vault-related issues.

Conclusion: Bioptics offered excellent long-term safe, predictable, and efficient outcomes for high myopic astigmatism and can be considered an option if toric ICL is not available. Results confirm that wavefront-guided photoablation remains an excellent option to manage residual refractive error after phakic IOL.

Keywords: bioptics; enhancement; excimer laser; implantable collamer lens.

Figure 1

Standard graphs for reporting refractive surgery. (A) Distribution of uncorrected distance visual acuity (UDVA) at 3-year against distribution of preoperative corrective distance visual acuity (CDVA). (B) Change in corrected distance visual acuity (CDVA) from baseline at 3-year postoperatively. (C) Refractive accuracy attempted versus achieved spherical equivalent refraction. (D) Distribution of manifest refraction (MSE) at 3-year postoperatively. (E) Comparison of refractive astigmatism preoperatively and at 3-year postoperatively. (F) Mean manifest refraction (MSE) from pre-enhancement up to 3 years postoperatively.

Figure 2

Overview of Alpins vectorial analysis of corneal astigmatism following laser enhancement surgery at 3-year postoperatively. The target-induced astigmatism (TIA) shows the range of astigmatism that the surgery intended to induce. The surgically induced astigmatism (SIA) shows the ranged of achieved astigmatism. The difference vector (DV), calculated as SIA minus TIA, shows the remaining astigmatism following enhancement. The correction index (CI), calculated as SIA divided by TIA, shows the under/overcorrection of the astigmatism treatment, and can be used as a measure of success with an optimal value close to 1.