Long Term Efficacy and Safety of Iris-Claw Phakic Intraocular Lens in the Management of Post Keratoplasty Astigmatism

Purpose: To demonstrate the efficacy and safety of iris-claw phakic intraocular lens (pIOL) in the treatment of post keratoplasty astigmatism. Setting: Cornea Unit, Ophthalmology Department - Unidade Local de Saúde de Santo António - Porto, Portugal. Design: Retrospective longitudinal study. Methods: Analysis of patients submitted to iris-claw phakic IOL implantation after previous Penetrating Keratoplasty (PK) or Deep Anterior Lamellar Keratoplasty (DALK) between January 2013 and December 2023. Patients submitted to other refractive procedures and without minimum 1-year follow-up were excluded. Demographic data, spherical equivalent (SE), uncorrected (UDVA) and corrected (CDVA) distance visual acuity was registered preoperatively, at the intermediate visit (12-18 months), 5 years, and 10 years postoperatively. Vector analysis to plot corneal Surgically Induced Astigmatism was performed. Endothelial cell density (ECD) was evaluated at each visit using the same specular microscope. Results: We enrolled 39 eyes of 29 patients submitted to Keratoplasty due to Keratoconus (71.8% [n=28] DALK). At the intermediate visit, 19 eyes (49%) had a postoperative UDVA ≥ 20/32, and 6 (15%) had ≥ 20/20. Efficacy index was 0.83. 16 (11%) achieved full refractive correction without loss of CDVA, and 9 (23%) gained ≥ 1 lines of vision. 28 (72%) eyes were within ±1.00 D of plano refraction. Globally, 25 (64%) eyes showed a residual astigmatism ≤1.00 D. Average annual ECD loss was 3.07% for DALK and 9.34% for PK (p=0.006). Conclusions: Iris-claw pIOL is effective for treating post keratoplasty astigmatism. Given the risk of progressive endothelial cell loss, strict follow-up is mandatory, especially after PK.