Toric Implantable Collamer Lens for the Treatment of Myopic Astigmatism

Abstract

Purpose: To report visual outcomes following surgical correction of myopic astigmatism with Visian Toric implantable collamer lens (ICL) (STAAR Surgical, Monrovia, CA, USA) at a single tertiary refractive center in the United States. Patients and Methods: Toric ICL was implanted in 96 eyes (55 patients) with mean preoperative sphere of −8.98 ± 3.04 diopters (D) and cylinder of −2.67 ± 1.02 D from December 2018 to February 2021. Primary visual outcomes of efficacy, safety, stability, predictability of refractive correction, and astigmatic analysis were reported at three and twelve months postoperatively. Secondary subjective outcomes included patient-reported dry eye symptoms and glare/halos at postoperative visits. Other secondary outcomes were biometric data and postoperative vault over time. Results: At three and twelve months, 75 and 46 eyes were evaluated, respectively. At twelve months, the mean manifest refraction spherical equivalent (MRSE) was −0.23 ± 0.47 D with 93% achieving within ±1.00 D of target refraction. The manifest refractive cylinder (MRC) at twelve months was −0.73 ± 0.51 D, with 86% within ±1.00 D of target. Uncorrected distance visual acuity (UDVA) was 20/20 or better in 74% of eyes at twelve months. No patients lost ≥2 lines of corrected distance visual acuity (CDVA) at twelve months. The mean angle of error was −0.9 ± 10.2° at three months and −1.6 ± 12.8° at twelve months. One patient required bilateral lens rotation, four patients underwent secondary enhancement with LASIK/PRK, and seven patients underwent postoperative limbal relaxing incisions. Conclusion: This initial single-site experience finds Toric ICL implantation for myopic astigmatism to be safe and effective. Patients can achieve markedly improved UDVA in a single surgery with stable vision over time and minimal adverse subjective symptoms.

Analysis of perioperative problems related to intraocular Implantable Collamer Lens (ICL) implantation

“…ICL surgery may lead to changes in the microenvironment of the eye surface, resulting in meibomian gland dysfunction, or even dry eyes. It was reported by Moshirfar M et al [ 6 ] that dry eye symptoms occurred in 13% of patients on the first day after surgery and peaked at about 29% at 3 months. According to the study of Paul J Dougherty et al, 5.8% of patients undergoing V4 ICL implantation had dry eye after surgery, mainly mild to moderate dry eye, without severe symptom [ 7 ].…”

“…Moreover, arch height also decreased with time and decreased the most from one month to three months after operation [ 63 – 76 ]. But it is also been reported in the literature that the average postoperative arch height will decrease significantly at 6 months after surgery and will remain basically stable thereafter [ 6 ]. Schmidinger reported that the arch height was reduced by an average of 28 μm per year [ 77 ], while Choi, JH's study showed that the value was 21 μm [ 78 ].…”

“…The incidence of spontaneous rotation of TICL was about 0.12% [ 86 ]. Majid Moshirfar et al 's study showed that 87% of patients rotated < 5° after TICL implantation and did not require additional intervention [ 6 ]. However, it was also reported that approximately 9.375% of patients had a cylinder axis rotation of 10° or greater occurred and required repositioning [ 95 ].…”

Phakic intraocular lenses: an update and review for the treatment of myopia and myopic astigmatism in the United States

“…A concern with any toric implant is the risk of rotation. Visian TICLs showed 87% of patients had rotation of <5 degrees and required no additional intervention over 12 months [15]. Another study found that after four years, 59.6% had residual astigmatism of -0.75D in EVO TICL, a similar finding in general spectacle wearers [17].…”

“…A study of 46 eyes implanted with Visian TICL found that 94% of target manifest residual spherical equivalent (MRSE) was achieved within AE1.00D. Manifest refractive cylinder (MRC) was within AE0.50D of its target in 49% of eyes, and 86% within AE1.00D of their target [15]. Encouragingly, another study achieved a more stable 92% MRC within AE0.50D using the same lens [16].…”