Surface cytologic features on intraocular lenses - Can increased biocompatibility have disadvantages?

Objective: To compare the anterior surface cytologic features and effect on blood-aqueous barrier of polymethyl methacrylate, silicone, and hydrogel i ntraocular lens (IOL) implants to give an indication of their biocompatibil ity. Methods: This prospective study was performed at an English-teaching hospit al. Ninety eyes were randomized to receive a polymethyl methacrylate, silic one, or hydrogel implant. A standardized surgical protocol was performed by a single surgeon using phacoemulsification. Patients were seen at interval s for 1 year. Measurements of visual acuity, contrast sensitivity, and ante rior chamber laser flare and cells were obtained: and an assessment of lens cytologic features using specular microscopy of the anterior IOL surface w as performed. Results: Visual acuity and contrast sensitivity were not significantly diff erent among the 3 groups. Hydrogel IOLs were associated with fewer inflamma tory cells on their surface than polymethyl methacrylate and silicone IOLs (P<.001), but with significantly more lens epithelial cells (LECs) (P<.001) . Patients with hydrogel implants without LECs had greater blood-aqueous ba rrier breakdown than those with LECs. Conclusions: The hydrogel IOLs were associated with a reduced inflammatory cell reaction but had many more LECs on their anterior surface. Those IOLs associated with increased blood-aqueous barrier damage did not develop LECs . if an IOL is too biocompatible, then it may incite the growth of LECs ove r its surface, which could have disadvantages.