Interface inflammation after laser in situ keratomileusis - Sands of the Sahara syndrome

Purpose: To determine the source of the interface debris that causes the in terface inflammation known as "sands of the Sahara" after laser in situ ker atomileusis (LASIK): Setting: Department of Ophthalmology, LSU Eye Center, Louisiana State Unive rsity Medical Center School of Medicine, New Orleans, USA. Methods: A microkeratome (Automated Corneal Shaper) was used to make a LASI K flap in 8 eyes of 4 rabbits. in 4 eyes, the blade was used directly from the sterile pack; in the contralateral 4 eyes, the blade was cleaned prior to use. In vivo confocal microscopy of the corneas was performed 1 day afte r surgery. An unused, cleaned bade and an unused, uncleaned blade, as well as blades used in the rabbit eyes, were examined by scanning electron micro scopy. Results: Confocal microscopy revealed numerous fragments of debris surround ed by inflammatory cells in the LASIK flap interfaces created by blades tak en directly from the sterile package. Interfaces created by the cleaned bla des showed only rare, scattered bits of debris. Scanning electron microscop y of the unused blades showed debris on the uncleaned blade removed directl y from the sterile package. Conclusion: Post-LASIK interface inflammation may be caused by debris on th e microkeratome blade, although other sources are possible. The interface d ebris and inflammation can be reduced or eliminated by cleaning the microke ratome blade before use.