Refractive change and photorefractive keratectomy treatment for a late traumatic flap loss

Abstract

A flap loss is rare and serious among various flap-related complications of LASIK. It can occur intra-operatively, early post-operatively or late post-operatively and can be classified aetiologically as iatrogenic or traumatic. Here, we report a case of late traumatic flap loss caused by a scratch from a cat's paw and successfully treated by PRK. A review of the literature indicates that this is the first case of late traumatic flap loss, for which the patient received a PRK re-treatment. With the increasing popularity of LASIK, the incidence of either iatrogenic or traumatic flap loss may increase and the awareness of this complication and the importance of its management should not be overlooked. CASE REPORTA 28-year-old woman underwent bilateral wavefront LASIK on 17 February 2007. The preoperative refractions were -6.00/ -2.25 ¥ 170 in the right eye and -8.00/ -2.50 ¥ 165 in the left eye for a visual acuity of 6/6 in both eyes. The keratometric values were 43.25@165/45.5@75 and 43.25@165/45.25@75 in the right and left eyes, respectively. The preoperative pachymetric readings were 562 mm for the right eye and 559 mm for the left eye. An automated microkeratome (Moria M2, Moria, Anthony, France) was used to create the flap with a superior hinge, followed by ablation with an excimer laser (VISX STAR S4 Inc, Santa Clara, CA) with the CustomVue software (VISX Inc, Santa Clara, CA). The attempted correction was -6.11/-1.94 ¥ 169 in the right eye and -8.15/-1.98 ¥ 165 in the left eye. The diameters of ablation zone were 8.0 mm in both eyes and the calculated ablation depth was 119 mm in the right eye and 151 mm in the left eye. The surgical course was uneventful. Six months after LASIK, her unaided vision was 6/6 in both eyes.On 20 January 2008, 11 months after LASIK, the left eye of this patient was scratched by a cat's paw, while she was playing with the cat in a pet store. The patient suffered from severe ocular pain and she noted a sudden decrease in visual acuity. She was sent to an emergency service, where a LASIK flap loss was diagnosed. A bandage contact lens was inserted with topical medications.Two days later, she came to our clinic. On examination, the unaided vision of the left eye was 6/150 and the VA was 6/15 with a manifest refraction of -4.50/-1.25 ¥ 75. A central corneal epithelial defect was found; it was 8 ¥ 8 mm in size and corresponded to the area of the previous LASIK flap (Figure 1). Topical 0.3% ciprofloxacin hydrochloride (Alcon Laboratories Inc, Fort Worth, TX), 0.1% fluorometholone (Alcon Laboratories Inc, Fort Worth, TX) and artificial tears were prescribed with a bandage contact lens for the affected eye. Four days after the flap loss, the epithelial defect healed and a moderate corneal haze presenting at the nasal and temporal sides remained, however, it spared the central visual axis (Figure 2). Three months after the flap loss, the unaided vision of the left eye was 6/18 and the VA was 6/9 with a refraction of -1.50/-0.75 ¥ 68. The topography showed an irregular astigmatism at that t...

Traumatic displacement of laser in situ keratomileusis flaps: an integrated clinical case presentation and literature review

“…A minus meniscus ap was created using a conventional microkeratome during LASIK. After ap loss, the underlying stromal bed with a steeper curvature would be revealed, causing a myopic change [10]. The postoperative refraction change and ASOCT image in case one were consistent with the postulation that the refraction change would re ect the ap morphology.…”