Corneal Densitometry Changes in Emmetropic Presbyopic Eyes Three Years After Sterile Allograft Corneal Lenticle Implantation

Purpose: To evaluate corneal densitometry changes in the eyes 3 years after allograft corneal inlay (ACI) implantation for refractive treatment of presbyopia. Methods: This retrospective case series included 32 nondominant eyes of 32 patients who underwent allograft corneal lenticle implantation. Corneal densitometry was performed preoperatively and postoperatively at 1, 3, 6, 12, and 36 months using a Scheimpflug tomography device. The results were analyzed in four different layers and four different zones of the cornea. Results: The mean age of the 32 included patients was 49.8±3.3 (range 45–56) years. The densitometric changes measured at 36 months were more prominent in zones 1 and 2, especially in the anterior layer (AL). The AL mean baseline densitometry values were 19.02±2.20 grayscale unit (GSU) for zone 1 and 17.50±1.89 for zone 2. Densitometry values increased significantly at 1-month (to zone 1:23.37±3.71 GSU, P <0.001 and zone 2:18.90±2.39 GSU, P =0.001) and 3-month follow-up (to zone 1:23.68±4.35 GSU, P <0.001 and zone 2:18.80±2.46 GSU, P =0.006). Between the 3-month and 6-month follow-up periods, the densitometry values returned to baseline levels and remained constant throughout the 36-month follow-up (to zone 1:19.98±1.96 GSU, P =0.414 and zone 2:18.11±2.13 GSU, P =1.000). No significant densitometric changes were observed in zone 3 at any time. Densitometric values returned to baseline levels in all layers and zones at 6 months postoperatively. Conclusion: These results support the notion that ACI implantation is relatively safe regarding corneal transparency.