Analysis of postoperative glare and intraocular lens design.
OBJECTIVE
To assess the potential for reflected glare images from commonly used intraocular lens (IOL) materials and designs.


METHODS
Mayo Clinic, Rochester, Minnesota, USA.


METHODS
The interaction of reflected light rays from 3 commonly used IOLs (Bausch & Lomb LI61U and P359UV; Alcon AcrySof(R) MA60BM) with different optic designs (equi-biconvex: 10.0 and 15.0 mm anterior radius of curvature; unequal biconvex: 32.0 mm anterior radius of curvature) and optic materials (silicone, poly[methyl methacrylate], and acrylic) were examined in an eye model using the Zemax optical design program. The potential of each IOL model to produce subjective glare was determined from the size of the defocused reflected glare image at the retina.


RESULTS
The unequal biconvex design concentrated reflected light on a retinal area that was 60-fold smaller than that of the equi-biconvex design. Increasing the refractive index of the IOL material from 1.43 (silicone) to 1.55 (acrylic) increased the amount of reflected light 5-fold. Compared to an equi-biconvex design composed of a lower refractive index material, the unequal biconvex design with a higher refractive index material increased the relative intensity of reflected light at the retina 300-fold, and for eyes with low corneal power the intensity increased 3500-fold. Similarly, for external glare apparent to an outside observer, the intensity of reflected light increased 400-fold and for low corneal power it increased 6000-fold.


CONCLUSIONS
An unequal biconvex IOL design (32.0 mm anterior radius of curvature) composed of a higher refractive index material increased the potential for postoperative glare and external reflections.
Erie
J C
JC
Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota 55905, USA. erie.jay@mayo.edu
Bandhauer
M H
MH
McLaren
J W
JW
D003198:Computer Simulation; D019466:Glare; D007910:Lenses, Intraocular; D008027:Light; D008954:Models, Biological; D055095:Optics and Photonics; D011183:Postoperative Complications / Q000378:metabolism*; D011474:Prosthesis Design; D012031:Refractometry