Original article
Laser in situ keratomileusis flap margin: wound healing and complications imaged by in vivo confocal microscopy

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Abstract

PURPOSE: To examine the healing response of laser in situ keratomileusis flap margin in vivo.

METHODS: Forty-three eyes of 43 patients who had undergone myopic (n = 39) or hyperopic (n = 4) laser in situ keratomileusis were examined once after surgery. The flap margin was imaged by in vivo confocal microscopy at various depths, and the wound healing response, flap alignment, and complications were evaluated. Ten eyes were examined on day 3 postoperatively, 13 eyes at 1 to 2 weeks, 10 eyes at 1 to 2 months, five eyes at 3 months, and five eyes at 6 months or later.

RESULTS: At 3 days after laser in situ keratomileusis, the surface epithelium and basal epithelium appeared normal. Keratocyte activation was strongest at 1 to 2 weeks and 1 to 2 months, and an increased amount of haze was observed correspondingly. Intrastromal epithelial cells forming a plug could occasionally be perceived in the wound gape. Wound constriction was completed in most cases by 3 to 6 months or later. Good alignment was observed in 12 of 43 flaps (27.9%) and moderate and poor alignment in 17 of 43 flaps (39.5%) and 13 of 43 flaps (30.2%), respectively. Poor alignment was not associated with lamellar epithelial ingrowth. Epithelial ingrowth was associated with dense haze at the interface. Diffuse lamellar keratitis was imaged in two corneas after hyperopic laser in situ keratomileusis.

CONCLUSIONS: The laser in situ keratomileusis incision wound at the flap margin appears to heal after the sequence observed in incisional wounds in nonhuman primates. Complications, such as lamellar epithelial in growth and diffuse lamellar keratitis, were often observed, particularly after hyperopic laser in situ keratomileusis.

Section snippets

Methods

The flap margin of 43 eyes of 43 patients (26 women and 17 men, age 33.6 ± 8.6 years; mean ± SD) who had undergone myopic (n = 39) or hyperopic (n = 4) laser in situ keratomileusis was examined once at different time points after surgery using in vivo confocal microscopy. The preoperative spherical equivalent of refraction of the myopic eyes was −6.74 ± 3.04 diopters (D) (range, −1.75 D to −12.25 D) and that of the hyperopic eyes was +4.12 ± 0.60 D (range, +3.75 to +5.0 D). The Ethical Review

Results

The predictability of the surgery at the time of follow-up was within 0.25 D of the desired result in 20 of 43 eyes (46.5%), within 0.5 D in 28 of 43 eyes (65.1%), within 1.0 D in 35 of 43 eyes (81.4%), within 2.0 D in 42 of 43 eyes (97.7%), and within 3.0 D in 43 of 43 eyes (100%).

Fifteen eyes (34.9%) presented flap striae, and three eyes presented larger folds (7.0%) on slit-lamp examination. In addition, the following complications were registered in seven of 43 eyes (16.3%): lamellar

Discussion

After laser in situ keratomileusis the healing patterns of the incisional wound at the flap margin and the central lamellar intrastromal wound are different. The wound-healing mechanisms of incisional wounds were recently reviewed by Jester and associates.14 In a nonhuman primate eye, the healing is initiated by an early sliding of the corneal epithelium over the wound margin followed by the formation of an epithelial plug in the wound cleft (observed at 7 days after partial thickness

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    This work was supported by the Instrumentarium Scientific Foundation, Helsinki, Finland; (Drs Vesaluoma, Valle, and Tervo), Alicante Institute of Ophthalmology, Alicante, Spain (Drs Vesaluoma, Valle, and Petroll), Finnish Medical Council, Helsinki, Finland, (Drs Tervo and Petroll), Helsinki University Central Hospital, Helsinki, Finland, (Drs Tervo and Vesaluoma), Finnish Eye and Tissue Bank Foundation, Helsinki, Finland, (Dr Vesaluoma), Finnish Eye Foundation, Helsinki, Finland, (Drs Vesaluoma and Tervo), Mary and Georg C. Ehrnrooth Foundation, Helsinki, Finland, (Dr Vesaluoma), Ella and Georg Ehrnrooth Foundation, Helsinki, Finland, (Dr Vesaluoma), The Friends of the Blind, Helsinki, Finland (Dr Tervo).

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