Purpose: To investigate the effects of cataract extraction and lens implantation on the central corneal endothelium 10 years after surgery.
Methods: The authors conducted a prospective study of 253 consecutive eyes that underwent cataract extraction with or without lens implantation by one surgeon from 1976 to 1982. Three types of lens implant were used during this period. The protocol included ophthalmic examinations and specular microscopy on all eyes preoperatively, and 2 months and 1, 3, 5, and 10 years postoperatively.
Results: The 10-year analysis was conducted on 67 (26%) of the 253 total eyes. The remaining patients died (86 eyes [34%]), were unable to return 10 years later (93 eyes [37%]), or had secondary implants (5 eyes [2%]) or penetrating keratoplasty (2 eyes [1%]). There were no statistically significant differences among the median 10-year endothelial cell losses of 36% in 17 control cataract extractions without lens implantation (15 extracapsular and 2 intracapsular), 40% in 15 medallion iris suture implants, 32% in 28 transiridectomy clip implants, and 32% in 7 posterior chamber implants. The median exponential rate of chronic cell loss from 1 to 10 years after surgery was 2.5% per year, which did not differ significantly among the three implant groups or between the implants (2.4% per year) and controls (2.7% per year). The chronic cell loss rate was significantly higher (7.2% per year) in six eyes with cornea guttata, which was the only preoperative endothelial morphologic feature that was significantly associated with the chronic cell loss rate.
Conclusions: Ten years after cataract extraction, eyes continued to lose endothelial cells from the central cornea at a rate of 2.5% per year, 2.5 to 8.0 times the rate in healthy unoperated eyes. The rate was not affected significantly by the presence of the three types of lens implants that the authors used. Postoperative eyes with cornea guttata continued to lose cells at more than twice this rate. Preoperative specular microscopy did not provide additional information helpful in predicting postoperative endothelial status or outcome.