How has confocal microscopy helped us in refractive surgery?

PURPOSE OF REVIEW: To summarize the known uses of in-vivo confocal microscopy in refractive surgery, highlighting the current developments in the field. RECENT FINDINGS: Examination of the cornea after laser in-situ keratomileusis demonstrated that the keratocyte density within the laser in-situ keratomileusis flap and anterior residual corneal bed continued to decline during the entire 3-year period of the study. The progressive loss of keratocytes in the flap and anterior portion of the residual corneal bed could have long-term implications in terms of corneal stability, refractive stability and cellular integrity after laser in-situ keratomileusis. Additional studies showed that the density of sub-basal nerves decreased by 90% 1 month after laser in-situ keratomileusis. At some point between 3 and 6 months after laser in-situ keratomileusis, the sub-basal nerves began to recover and by 2 years they had reached approximately 50% of their original preoperative density. Analysis of sub-basal nerve density after photorefractive keratectomy reported that the nerve density completely recovered to preoperative levels by 2 years. Other confocal microscopic studies demonstrated that the microscope can detect infectious organisms in vivo, without stains or dyes. SUMMARY: The confocal microscope is a unique diagnostic instrument that can be used to evaluate corneal healing, long-term stability and to assess complications after refractive surgery. The ability of the device to view in-vivo cellular detail, microorganisms, inflammatory cells, epitheliod cells, fibrosis and measure the postoperative thickness of the residual corneal bed after laser in-situ keratomileusis, in a noninvasive manner, highlights the unique capabilities of this instrument.