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.
Hollick
E J
EJ
Department of Ophthalmology, St Thomas' Hospital, London, England.
Spalton
D J
DJ
Ursell
P G
PG
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