Three Year Follow-Up Of The Carlevale Intraocular Lens: Evaluating Changes In Scleral Pocket Thickness

To investigate the long-term effects, including complications, and dynamic changes in scleral thickness above the t-haptic, associated with the Carlevale sutureless, scleral-fixated intraocular lens (sSFIOL). 

Single-center, single surgeon, prospective clinical trial, Department of Ophthalmology, Medical University of Vienna.

Thirty-six eyes of 36 consecutive patients underwent a 3-year follow-up, with imaging 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.  

In this study of 36 eyes with Carlevale IOL implantation, the mean follow-up period was 28 ± 11 months. 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. 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.  

Our study demonstrates a significant improvement in BCVA postoperatively. While there is a slight increase in IOL tilt and decrease in IOL decentration, both seem to not be clinically significant. We observed a thinning of the scleral pocket thickness. Even when slight the question arises if the scleral pocket thickness is of clinical significance or if a subconjunctival placement of the T-haptics is acceptable in the long term. Further studies are necessary to evaluate the long term patency of the scleral pocket.