Abstract
Purpose: :
Accommodating intraocular lenses are a promising technology for the correction of pseudophakic presbyopia. In order to succeed, these lenses should provide functional near vision sustainable over time. To assess this, we evaluated reading speed at 1 year and 2 years in patients implanted bilaterally with the Synchrony dual optic IOL.
Methods: :
Prospective, non comparative series of cases. A high contrast reading speed chart in Spanish was developed based on the MNRead chart. Font, size and style were maintained, and the same structure of sentences with 60 characters divided into 3 text lines and 10 standard (3rd grade level) words per sentence were used. All measurements were obtained at 40 cm. Distance corrected near visual acuity (DCNVA) and reading speeds without near add were evaluated in nineteen bilateral Synchrony patients at 10.12 months (1 year) and 22.13 months (2 years) average follow-up visit. Reading speeds were measured at 1.0 to best achievable logRAD acuity to calculate threshold reading acuity, critical print size (CPS), reading speed at 0.4 logRAD and maximum reading speed.
Results: :
Four patients could not read 150 words/ minute (wpm) at any font size either at the 1 year or 2 year intervals and were excluded from statistical analysis. A 2-way ANOVA showed a significant effect of print size (p<0.05) and year of testing (2 year better than 1 year; p < 0.05), while the interaction effect was not significant (p = 0.14). DCNVA was linearly correlated with threshold reading acuity at both 1 year (r2: 0.70, p < 0.05) and 2 years (r2: 0.60, p < 0.05). DCNVA was not different between 1 and 2 years (0.09 vs. 0.05 logMAR; paired t-test, p = 0.35). Reading acuity was significantly better at 2 years (0.07 logRAD) than at 1 year (0.11 logRAD) (paired t-test, p < 0.05). There was no statistical difference in reading speed at 0.4 logRAD (newspaper print size) between 1 year (mean ± SD: 180.5 ± 61wpm) and 2 years (mean ± SD: 184.2 ± 42 wpm). Overall, functional near vision measures were stable from 1 to 2 years.
Conclusions: :
This study demonstrates the long term performance of the Synchrony accommodating IOL in providing excellent distance corrected near vision and reading ability.
Keywords: intraocular lens • accomodation • reading