Intraoperative flap re-cut after vertical gas breakthrough during femtosecond laser keratectomy

The observation during small incision lenticule extraction for myopia with corneal opacity

Background

To evaluate the feasibility and efficacy of small incision lenticule extraction (SMILE) in the treatment of myopia with corneal opacity.

Methods

To evaluate the treatment of myopia with corneal opacity, 9 patients (4 males, 5 females) who underwent SMILE were enrolled in this prospective clinical study. One eye of each patient was treated. The results of laser scanning and lenticule extraction were observed during the surgery, and the surgical videos were again reviewed after surgery. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and spherical equivalence (SE) were noted at 1 month after surgery. The depth and density of the corneal opacities were measured by anterior segment optical coherence tomography (AS-OCT) and the Pentacam anterior eye segment analyzer.

Results

All procedures were uneventful and no intraoperative complications were observed. At 1 month after surgery, the UDVA of all patients was 20/25 or better and no patients lost Snellen lines. The mean safety and efficacy indexes were 1.10 ± 0.24 and 1.08 ± 0.16, respectively, at 1 month postoperatively. The mean postoperative spherical equivalent was 0.27 ± 0.23 diopter (D). All eyes were within ±0.75 D and 8 eyes (88.9%) were within ±0.50 D. There was no eccentric corneal topography or abnormal morphology in the corneal caps. The corneal opacities of all patients were within the optical zone. The mean preoperative depths in the deepest areas of corneal opacity were 152 ± 38 μm (range: 86–217 μm); at 1 month after surgery (P < .01), they were 117 ± 28 μm (range: 86–189 μm). The preoperative maximum density of corneal opacity was 48.5 ± 20.7 (range: 20.4 to 85.8); at 1 month after surgery (P > .05), it was 49.8 ± 26.7 (range: 19.8 to 82.5) at 1 month after surgery.

Conclusion

Patients with corneal opacity can be successfully treated with the SMILE operation. The short-term outcome was good, however the long-term results need further study.

Trial registration

The trial registration number: ChiCTR-ONRC-13003114, Date of Last Refreshed on: 2016-01-27, Date of registration on 2013-03-17(retrospectively registered).

Evaluation of LASIK treatment with the Femto LDV in patients with corneal opacity

PURPOSE

To evaluate the relative effectiveness and safety of LASIK using the Femto LDV (Ziemer Ophthalmic Systems AG) and IntraLase FS 60 (Abbott Medical Optics Inc) femtosecond lasers in patients with corneal opacity.

METHODS

Patients with corneal opacity were retrospectively selected between March and July 2009. For this study, 205 eyes with 90-μm corneal flaps created using the Femto LDV (LDV group) and 200 eyes with corneal flaps created using the IntraLase FS 60 (Intra-Lase group) were selected. The flap thickness of the IntraLase group was determined by observation with slit-lamp microscopy. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction spherical equivalent (MRSE) were measured pre- and postoperatively and were statistically evaluated using the Student t test and Mann-Whitney U-test.

RESULTS

Regardless of the levels of opacity, eyes in the LDV group experienced uneventful procedures with no complications. Eyes in the IntraLase group had corneal flaps of 100- to 130-μm thickness and uneventful procedures; however, gas breakthrough was observed in 27 eyes. Of all eyes, 117 eyes from the LDV group and 109 eyes from the IntraLase group were available for 3-month follow-up. Mean 3-month postoperative UDVA, CDVA, and MRSE for the LDV group were 20/12.5, 20/12.5, and 0.17±0.32 diopters (D), respectively, and for the IntraLase group were 20/12.5, 20/12.5, and 0.11±0.34 D, respectively. No statistically significant differenes were noted in UDVA, CDVA, or MRSE between groups (P>.05 for all).

CONCLUSIONS

Laser in situ keratomileusis with the Femto LDV created thin flaps regardless of level of opacity and induced no complications as compared to the IntraLase FS 60, where gas breakthrough was significantly more common.