Abstract
Purpose :
To evaluate photic phenomena, such as positive dysphotopsia or glare for five marketed intraocular lens (IOL) models by combining both non-sequential ray trace simulations in a schematic model eye and in vitro methods. These types of phenomena can be affected by the edge profile and peripheral optic geometry of the IOL as well as pupil size.
Methods :
Five monofocal IOL models (Alcon AcrySof SN60WF, AMO Tecnis ZCB00, B&L enVista MX60, Santen Eternity W-60 and Hoya Vivinex XY1) were used to evaluate positive dysphotopsia or glare-type photic phenomena. Optical ray trace simulations of incoming light were generated based on a collimated light source with a wavelength of 550 nm for various off-axis angles of illumination and both at mesopic and photopic pupil sizes. The simulation analyses were verified using a laboratory glare measurement system, whereby off-axis glare characteristics are formed from illumination of IOLs at various angles.
Results :
Non-sequential ray trace model eye simulations and in vitro methods showed that SN60WF IOL produced focused off-axis images compared to all other IOL types. The ZCB00 and MX60 IOLs produced dispersed images along with marked glare characteristics at 45 degrees of off-axis illumination and above, likely because of both designs’ reduced usable optic diameter and peripheral non-imaging optic geometry. The Eternity W-60 IOL showed the highest edge reflected glare characteristic, likely because of its straight optic edge geometry. Vivinex XY1 IOL produced a focused image similar to SN60WF, but with edge transmitted glare. The results also demonstrate that glare or positive dysphotopsia type photic phenomena are considerable at mesopic pupil size.
Conclusions :
Peripheral non-imaging optic geometry and straight edge profiles may contribute to positive dysphotopsia. IOL designs with full functional optics and precision edge curvature demonstrated the lowest level or absence of glare over a wide range of incident angles at both mesopic and photopic pupil sizes. Only clinical studies can confirm if the in vitro differences are clinically significant.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.