Refractive lenticule extraction flap and stromal bed morphology assessment with anterior segment optical coherence tomography

PurposeTo evaluate the flap and stromal bed after refractive lenticule extraction using optical coherence tomography (OCT).SettingSingapore National Eye Centre, Singapore.DesignLongitudinal case series.MethodsHorizontal scans (RTVue) were taken preoperatively and after refractive lenticule extraction. Two procedures were performed: femtosecond lenticule extraction and small-incision femtosecond lenticule extraction. Flap and bed thicknesses were measured at the center (0.0 mm) and 1.5 mm and 3.0 mm to either side.ResultsAt 1 week, the mean flap at 0.0 mm was borderline thicker (P=.056) and at +3.0 mm significantly thicker after femtosecond lenticule extraction than after small-incision femtosecond lenticule extraction (P=.003). The mean bed at 0.0 mm was thinner after femtosecond lenticule extraction (P=.03). The flap at −3.0 mm showed thinning between 1 week and 3 months after small-incision femtosecond lenticule extraction (P=.018). The flap at +3.0 mm thinned between 1 week and 1 month after femtosecond lenticule extraction (P=.009). After femtosecond lenticule extraction, there were increases in bed (P=.027) and total corneal (P=.013) thicknesses at 0.0 mm between 1 week and 3 months, remaining stable thereafter (3 months: P=.842 and P=.508, respectively). The mean spherical equivalent decreased and the uncorrected acuity improved after both procedures (P<.001), with stabilization of both variables at 3 months.ConclusionA significant difference in stromal bed thickness between femtosecond lenticule extraction and small-incision femtosecond lenticule extraction was detectable by AS-OCT 1 week postoperatively.Financial DisclosureNo author has a financial or proprietary interest in any material or method mentioned.