Visual Impact of Decentering Hydrogel Presbyopia-Correcting Corneal Inlay
Narrative Responses:
Purpose
To evaluate the effect on visual acuity (uncorrected) of placement accuracy of a thin presbyopia-correcting hydrogel inlay (Raindrop Near Vision Inlay) through wavefront maps.
Methods
Raindrop Near Vision Inlay is a small hydrogel inlay implanted under a femtosecond laser corneal flap, centered on the light constricted pupil center. We analyzed retrospectively 125 subjects that were implanted with the inlay (targeting the center of the pupil). Wavefront aberrometry (iTrace, Tracey technologies) was used to determine inlay position within the pupil [target in the X (temporal/nasal) and Y (inferior/superior) directions relative to the pupil center]. Uncorrected visual acuity (distance, intermediate and near) was assessed using standardized ETDRS charts to evaluate the effects of inlay centration.
Results
Uncorrected visual acuity remained stable at very high levels (0.1 logMAR for distance, intermediate and near) in subjects with up to 0.9 mm of inlay decentration (98% of all inlays) measured at 1 month with iTrace wavefront scans. In eyes with inlay decentration between 0.9 mm and 1.25 mm (worst case), near acuity decreases though intermediate and distance visual acuities remained stable. The low number of decentered inlays prevented statistical confidence in the range beyond 0.6 mm.
Conclusion
Raindrop Near Vision Inlay’s centration is easily achieved by placing the small hydrogel inlay over the center of the light-constricted pupil. This task was achieved in 98% of cases. Clinically significant decentration (more than 0.9 mm) occurs infrequently (2%) and decreases near visual acuity without compromising intermediate or distance vision.