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 intraocular lens (IOL) implants to give an indication of their biocompatibility.


METHODS
This prospective study was performed at an English-teaching hospital. Ninety eyes were randomized to receive a polymethyl methacrylate, silicone, or hydrogel implant. A standardized surgical protocol was performed by a single surgeon using phacoemulsification. Patients were seen at intervals for 1 year. Measurements of visual acuity, contrast sensitivity, and anterior chamber laser flare and cells were obtained; and an assessment of lens cytologic features using specular microscopy of the anterior IOL surface was performed.


RESULTS
Visual acuity and contrast sensitivity were not significantly different among the 3 groups. Hydrogel IOLs were associated with fewer inflammatory 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 barrier 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 over its surface, which could have disadvantages.
Department of Ophthalmology, St Thomas' Hospital, London, England.
E J
EJ
Hollick
D J
DJ
Spalton
P G
PG
Ursell
D000368:Aged; D000369:Aged, 80 and over; D001672:Biocompatible Materials; D018916:Blood-Aqueous Barrier; D002452:Cell Count; D015350:Contrast Sensitivity; D004847:Epithelial Cells / Q000473:pathology*; D015622:Epithelioid Cells / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000473:pathology*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D019654:Lens Implantation, Intraocular; D007908:Lens, Crystalline / Q000473:pathology*; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D019904:Polymethyl Methacrylate; D011446:Prospective Studies; D012826:Silicone Elastomers; D014792:Visual Acuity
D001672:Biocompatible Materials; D012826:Silicone Elastomers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D019904:Polymethyl Methacrylate