United States Military Implantable Collamer Lens Surgical Outcomes: An 11 Year Retrospective Review

Purpose To examine the long-term efficacy and safety of myopic implantable collamer lens (ICL) implantation in active duty US military personnel. Setting Hospital practice. Design Retrospective longitudinal observational study. Methods 1485 patients (median age: 25, Inter-quartile range: 22, 29) underwent ICL surgery. Patients received a preoperative exam including uncorrected visual acuity (UDVA), intraocular pressure (IOP), manifest refraction measuring best corrected visual acuity (CDVA), corneal topography and tomography, qualitative grading of perceived ectatic risk, ophthalmic biometry, and baseline endothelial cell counts (ECC). Outcome measures included UDVA, IOP, vault size, manifest refraction, CDVA, and ECC. Long-term follow-up data ware drawn from the US Military medical record system. Results A total of 3105 eyes were evaluated. Patients received ICLs either due to abnormal topography 68% (2111 eyes) or due to high myopia 32% (994 eyes). Nearly 80% (94 eyes) of eyes maintained UDVA of 20/25 or better up to 8 years postoperatively. The rate of achieving the desired refractive correction was 97% (503 eyes) at 1 year and 90% (81 eyes) at 8 years. Stability of these outcomes were also shown by minimal change in manifest refraction. Documented mean ECC loss was 22% at post-operative year 5. The overall rate of adverse events was 1.2% (36 eyes) including visually significant cataract formation, glaucoma, retinal detachment, and traumatic incision opening. A removal/replacement rate of 4.5% (135 eyes) was observed. Conclusions ICL implantation was found to be effective and safe. Vault sizes decreased over time suggesting an increased risk of cataract formation after seven years. Further study is necessary to assess long-term clinical significance of ECC decline.