Long-term endothelial cell loss following phacoemulsification: model for evaluating endothelial damage after intraocular surgery.

BACKGROUND: Newer concepts of phakic intraocular lens (IOL) surgery present concerns as to their long-term deleterious effect on the endothelium. We examine the behavior of the endothelium for up to 6 years following uneventful phacoemulsification surgery, to establish a baseline for what might be an acceptable level of endothelial cell loss due to intraocular surgical trauma.

METHODS: Ninety-three eyes undergoing phacoemulsification surgery who had multiple endothelial specular microscopy examinations for up to 6 years were examined. Central endothelial specular photomicrographs were analyzed in all cases and the percent of endothelial cell loss as a function of time was calculated. Cell density calculations were corrected for the normal endothelial cell loss as a function of age.

RESULTS: Routine uncomplicated phacoemulsification surgery demonstrated a 9% endothelial cell loss 1 year postoperatively. This is in marked contrast to the 16% average endothelial cell loss cited in the literature after phakic AC-IOL surgery. In general, anterior chamber IOL surgery following cataract removal compares unfavorably to posterior chamber IOL insertion long term (20% cell loss versus 12% cell loss).

CONCLUSIONS: A model is proposed to look at the rate of endothelial cell loss that would be significant enough to create the threat for corneal edema long term following refractive intraocular surgery in young patients. Suggestions for critical comparisons between the observed endothelial aging seen with phakic IOLs and values for more routine IOL surgery are proposed to predict the long-term threat for endothelial cell loss and corneal decompensation, which might result many years after phakic refractive IOL surgery.