Abstract
Purpose :
As advancements in cataract surgery have led to improved outcomes, there has been an increased awareness of the undesired optical phenomenon known as negative dysphotopsia (ND). Current literature suggests that both the axis of placement and the lens material may influence the development of ND. Plate-shaped collamer intraocular lenses (PSC-IOLs) offer the promise of reducing ND due to a difference in shape and material as compared to C-shaped acrylic IOLs. Our study reports the incidence of NDs associated with PSC-IOLs and determines if there is an ideal axis of placement to reduce its incidence.
Methods :
157 cases of PSC-IOLs (Staar Nanoflex, Monrovia, CA) implanted after cataract surgery were reviewed from June 2015 – Nov 2017. With respect to IOL orientation, 65 PSC-IOLs were placed in the oblique axis, with 33 placed in the 135-315 axis and 32 in the 45-225 axis. An additional 45 PSC-IOLs were placed in the horizontal axis and 45 PSC-IOLs in the vertical axis. Currently, there are no recommendations for optimal axis placement for PSC-IOLs other than placement within the capsular bag. The relative incidence of ND based on orientation was assessed using chi-squared tests. The absence or presence of ND was noted at one-day, one-week, one-month and six-month follow-up with significance determined using Fisher’s exact test.
Results :
There was no statistically significant difference in the incidence of ND based on PSC-IOL orientation (p=0.71). We also did not find a statistically significant difference in the rate of ND longitudinally in the post-operative period among any of the groups based on PSC-IOL orientation (p=1). There was a statistically significant correlation between the presence of ND and a visible capsulorrhexis edge (CRE) on examination. If the CRE was visible on the first post-operative day, the patient was more likely to experience ND (p<0.05). However, this did not hold true at the subsequent post-operative visits.
Conclusions :
Although our data is limited by a small population size, we note that the incidence of ND is low with PSC-IOLs as compared to ND rates reported with acrylic IOLs. Furthermore, it does not appear that orientation of the PSC-IOL correlates with ND incidence. However, the presence of a visible CRE may be a positive predictor of ND. To the best of our knowledge, this represents the first report of ND incidence with PSC-IOLs.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.