Treatment of Corneal Opacity by Planned Lamellar Keratectomy Using the Femtosecond Laser

Long-term clinical outcome of femtosecond laser-assisted lamellar keratectomy with phototherapeutic keratectomy in anterior corneal stromal dystrophy

Purpose

To evaluate long-term outcome of femtosecond laser-assisted lamellar keratectomy (FLK) with phototherapeutic keratectomy (PTK) in patients with anterior corneal stromal dystrophies.

Methods

A total of 10 eyes from seven patients who underwent FLK were included. The patients had suffered from recurrent corneal erosion or visual disturbance in anterior corneal dystrophies (five Avellino dystrophies and two lattice dystrophies). Planar-shaped lamellar keratectomy was performed using femtosecond laser. The amount of corneal excision was determined by the depth of corneal opacity. Additional PTK with mitomycin C application was performed for smoothening of corneal cut surface. The patients were evaluated with following parameters: uncorrected visual acuity, best-corrected visual acuity (BCVA), mean anterior keratometric value, corneal irregularity, corneal high-order aberrations (HOA) and the recurrence of corneal erosion.

Results

Mean duration of follow-up was 64 months (2.5–9.5 years). The BCVA improved more than two lines of Snellen chart at last visit. The changes of keratometric values were within ±1 D in eight out of 10 eyes. Corneal irregularities in central 5 mm cornea and the values of total corneal HOA in central 6 mm cornea decreased by 0.3–3.1 D and 0.01–2.2 µm, respectively. Corneal erosion did not recur in any of those patients during follow-up and corneal dystrophy did not recur in eight out of 10 eyes.

Conclusion

In anterior corneal stromal dystrophies, FLK with PTK can be an effective surgical option to improve VA through decreasing corneal irregularities and HOA, while minimising corneal curvature changes.

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).

Femtosecond Laser-Assisted Lamellar Keratectomy for Corneal Opacities Secondary to Anterior Corneal Dystrophies: An Interventional Case Series

PURPOSE

To report results of femtosecond laser-assisted lamellar keratectomy (FLK) for corneal opacities secondary to anterior corneal dystrophies.

METHODS

Patients with a clinical diagnosis of Reis-Bücklers corneal dystrophy, granular corneal dystrophy, lattice corneal dystrophy, and macular corneal dystrophy were treated. FLK was performed to remove a central corneal free cap of 9.5 mm in diameter at a depth of 110 to 140 μm on which histological analysis was undertaken. Preoperative and postoperative refraction, best spectacle-corrected visual acuity, corneal topography results, and color photographs were recorded. Postoperative in vivo confocal microscopy of the cornea was performed. Changes in uncorrected visual acuity and best spectacle-corrected visual acuity, keratometry, refractive error, corneal irregularity, residual or recurrent central corneal opacities, and corneal haze were used to assess the outcome.

RESULTS

Eight eyes of 6 patients were treated. The clinical diagnosis was confirmed histologically in all cases. Visual acuity improved significantly from 0.49 ± 0.2 logMAR to 0.14 ± 0.13 logMAR after a mean follow-up of 29 ± 14 (range 8-54) months. Residual central stromal opacities were noted in 5 of 8 eyes immediately postoperatively. Clinically significant recurrence of disease was noted in 1 eye. Keratometry and refraction remained stable, and no further surgical intervention was needed. Patients with stromal corneal dystrophies had worse outcome than those with Reis-Bücklers corneal dystrophy.

CONCLUSIONS

In this case series, FLK provided both therapeutic and diagnostic intervention, delaying more invasive surgery. In vivo confocal microscopy showed signs of postoperative corneal stromal neuropathy.