Long-term results after sutureless intrascleral fixation of the Carlevale intraocular lens: Changes in scleral pocket thickness over time.

Purpose: To investigate the long-term effects and dynamic changes in scleral thickness above the T-haptic after sutureless scleral-fixated intraocular lens (sSFIOL) implantation using the FIL-SFF Carlevale lens.

Setting: Single-centre, single-surgeon, prospective clinical trial, Department of Ophthalmology, Medical University of Vienna, Austria.

Methods: Thirty-six eyes of 36 consecutive patients met the inclusion criteria for this post hoc analysis. Visual acuity, tilt and decentration of the IOL, as well as complications, were evaluated alongside imaging of the scleral pockets during multiple time points using the anterior optical coherence tomography (AS-OCT) system Tomey CASIA 2 in the bleb mode. The OCT scan pattern, oriented parallel to the T-shaped haptic of the IOL, facilitated manual analysis of images to measure scleral pocket thickness on both the temporal and nasal haptics. To compensate for distortions and non-perpendicular image acquisition, distal T-haptic thickness was also measured to calculate the relative scleral pocket thickness. For statistical evaluation, a linear mixed model was used, where we corrected for multiple measurements.

Results: The mean follow-up period was 28 ± 11 months. Measured scleral thickness above the T-haptic exhibited a significant decrease on both temporal and nasal sides, translating to an estimated annual decrease of approximately 0.03 mm (p < 0.001). Postoperatively, best-corrected visual acuity (BCVA) significantly improved from 0.77 ± 0.74 logMAR preoperatively to 0.41 ± 0.60 (p < 0.001). IOL tilt increased slightly from 7.23° ± 3.43° to 7.71° ± 3.70° (p = 0.003), while decentration significantly decreased from 0.41 ± 0.21 to 0.39 ± 0.20 mm (p < 0.001) postoperatively.

Conclusions: Long-term evaluation of Carlevale sSFIOL implantation demonstrated a significant improvement in postoperative BCVA. However, we observed a thinning of the scleral pocket thickness, raising questions about its clinical significance and the viability of subconjunctival placement of T-haptics in the long term. Further studies are necessary to evaluate the long-term patency of the scleral pocket.