Buttonholes during LASIK: etiology and outcome.

PURPOSE: To report the clinical features and outcome of eyes with flap buttonhole during LASIK. METHODS: A retrospective review was performed to identify eyes that developed flap buttonhole during Hansatome microkeratome translation. Pre-, intra-, and postoperative data were obtained to identify factors predictive of buttonhole. RESULTS: Five patients with buttonhole were identified from June 2001 through September 2002 (5 [0.06%] eyes of 7672 primary LASIK procedures). Mean patient age was 49.2 +/- 11.3 years (range: 37 to 66 years). Mean preoperative spherical equivalent refraction was 4.92 +/- 2.90 diopters (D) (range: -2.25 to -9.50 D). Mean keratometry was 45.59 +/- 1.15 D (range: 43.90 to 47.60 D). All 5 flap buttonholes occurred in the second of 2 consecutively treated eyes (P = .03). Buttonhole occurred in 2 (0.26%) of 778 eyes where the 160-microm microkeratome plate was used, and 3 (0.06%) of 4350 eyes where the 180-microm plate was used (P = .16). Two eyes received laser ablation at the time of buttonhole formation. In the untreated cases, the buttonhole flap itself caused a myopic spherical change of -0.50 D and 0.70 D of astigmatism. One of 5 eyes lost 2 lines of best spectacle-corrected visual acuity; this eye received laser ablation immediately after buttonhole formation. CONCLUSIONS: Buttonholes are significantly more likely to occur in the second of two consecutively treated eyes. A new blade for the second eye when the flap in the first eye appears to be thin should be considered. Caution should be exercised when considering laser ablation immediately following buttonhole formation.

Repositioning the laser in situ keratomileusis flap at the slit lamp.

PURPOSE: To describe the indications and technique for repositioning the laser in situ keratomileusis (LASIK) flap at the slit lamp. METHODS: We present a description of patients with striae or slippage of the flap who had repositioning of the flap at the slit lamp. RESULTS: Indications for repositioning at the slit lamp are mostly flap striae. However, it can also be done for a displaced flap and small amounts of debridement. This procedure is not recommended for taking cultures, irrigation of diffuse lamellar keratitis, suturing the flap, or epithelial ingrowth. Repositioning the flap is done by finding the edge of the flap with the cannula, lifting the flap, sweeping the cannula to release the entire wound, and infusing balanced salt solution under the entire flap. We did not encounter infection or recurrent epithelial erosion in these patients. CONCLUSIONS: Repositioning the LASIK flap at the slit lamp was effective and safe in the treatment of striae or flap slippage. It saved time, money, and, anxiety for the patient.

Asymmetric keratoconus attributed to eye rubbing.

PURPOSE: To report a series of cases with asymmetric keratoconus attributed to eye rubbing, discuss its pathogenesis, and review the literature. METHODS: Case reports and literature review. RESULTS: A careful history obtained from 5 patients with asymmetric keratoconus revealed habitual eye rubbing of the more severely affected eye. CONCLUSIONS: Trauma, such as occurs with habitual eye rubbing, plays a role in the pathogenesis of keratoconus.

Simultaneous wavefront-guided photorefractive keratectomy and corneal collagen crosslinking after intrastromal corneal ring segment implantation for keratoconus.

PURPOSE: To study the results of simultaneous photorefractive keratectomy (PRK) and corneal collagen crosslinking (CXL) in keratoconus after previous intrastromal corneal ring segment (ICRS) implantation. SETTING: Enaim Laser Center, Jerusalem, Israel. DESIGN: Case series. METHODS: This study comprised patients with moderate keratoconus who had previous Intacs ICRS implantation with the Intralase laser at least 6 months before PRK-CXL. Wavefront-guided PRK and ultraviolet-A CXL were performed simultaneously. Refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, keratometry (K) values, endothelial cell count (ECC), pachymetry, corneal resistance factor (CRF), and corneal hysteresis (CH) were assessed 3, 6, and 12 months postoperatively. RESULTS: Twelve months after PRK-CXL, the mean decimal UDVA improved significantly from 0.20 ± 0.12 (SD) to 0.55 ± 0.15 (P<.01). The mean decimal CDVA improved from 0.58 ± 0.13 to 0.77 ± 0.17 (P=.01). The mean cylinder decreased from -3.60 ± 1.70 to -1.30 ± 1.10 diopters (D) (P<.001). The mean apex K decreased from 50.91 ± 5.50 D to 46.61 ± 4.52 D (P<.005). The other corneal parameters did not change significantly after treatment. No significant difference was found between the 6-month and 12-month results. No patient lost lines of CDVA. Mild haze remained in 11.1% of eyes 12 months after treatment. CONCLUSIONS: Simultaneous wavefront-guided PRK and CXL for keratoconus after ICRS implantation was safe and effective. It significantly improved the UDVA, CDVA, and central K value, and consequently the visual function, of patients with moderate keratoconus.

Lymphocytic reaction to ultraviolet radiation on rabbit conjunctiva.

We examined the clinical and histological effects of controlled UV radiation on the conjunctiva and cornea of rabbit eyes by duration of exposure (0.5-4 hours daily for 5 consecutive days). Longer UV exposure (day 1-day 5) was associated with increased conjunctival redness, corneal erosion, edema and opacity. This study shows that UV irradiation leads to clinical and histological changes which may reflect an immune reaction to damaged epithelial cells.

Retinal microangiopathies overlying pigment epithelial detachment in age-related macular degeneration.

PURPOSE: To evaluate alterations in the retinal vasculature overlying pigment epithelial detachments (PED) in exudative age-related macular degeneration (ARMD) using indocyanine green and fluorescein angiography. METHODS: Forty-one patients (41 eyes) with a clinical diagnosis of exudative ARMD with PED underwent simultaneous fluorescein and indocyanine green angiography, also under high (10 degrees ) magnification. Vascular abnormalities in the retina were compared between patients with vascularized (n = 34, group 1) and nonvascularized (n = 7, group 2) PED on indocyanine green angiography and correlated with the size of the PED and the presence of serous retinal detachment. RESULTS: In all, 67 vascular abnormalities were found by indocyanine green angiography and only 22 by fluorescein angiography; this finding was statistically significant (P < 0.0001). The finding of retinal vasculopathy (32 patients in group 1 and two patients in group 2) was directly correlated with the presence of choroidal neovascularizations (P = 0.002). There was also a direct correlation between the presence of choroidal neovascularization and size of the PED (P = 0.03). The number of retinal vascular findings was not significantly correlated with serous elevation of the retina. CONCLUSIONS: Retinal vasculopathies may be observed in eyes with PED and are detectable by indocyanine green and fluorescein angiography.