Femtosecond-Assisted Lamellar Keratoplasty in Atypical Avellino Corneal Dystrophy of Indian Origin

Management of Stromal Corneal Dystrophies; Review of the Literature with a Focus on Phototherapeutic Keratectomy and Keratoplasty

Corneal dystrophies are a group of non-inflammatory inherited disorders of the cornea. This review considers treatment options for epithelial-stromal and stromal corneal dystrophies: namely Reis–Bücklers, Thiel–Behnke, lattice, Avellino, granular, macular and Schnyder corneal dystrophies. Where there is visual reduction, treatment options may include either phototherapeutic keratectomy (PTK) or corneal transplantation. Due to the anterior location of the deposits in Reis-Bücklers and Thiel–Behnke dystrophies, PTK is considered the treatment of choice. For lattice, Avellino, granular and macular corneal dystrophies, PTK provides temporary visual improvement; however, with recurrences, repeat PTK or a corneal transplant would be needed. For Schnyder dystrophy, should treatment be required, PTK may be the preferred option due to the potential for recurrence of the disease in corneal transplantation. This review discusses the literature and evidence base for the treatment of corneal dystrophies in terms of visual outcomes and recurrence rate.

Tuck In Femtosecond Laser Assisted Anterior Lamellar Keratoplasty (T-FALK) for the Management of Superficial Anterior Corneal Scars-A Modified Technique

PURPOSE

To report a modified sutureless and glue-less technique, termed tuck in femtosecond laser assisted anterior lamellar keratoplasty (T-FALK), and to achieve a good graft-host junction apposition.

METHODS

This is a prospective interventional case series of 15 eyes of 15 patients who underwent T-FALK. Depth of the anterior corneal scar was assessed using anterior segment optical coherence tomography (ASOCT). The donor and recipient lenticules were prepared using femtosecond laser. After removing the recipient anterior scarred lenticule, the transparent donor lenticule was positioned on the recipient bed and margins tucked in under the recipient cornea. A bandage contact lens was applied for 3 weeks. Postoperatively, topical antibiotic and steroid combination eye drops were given, and the assessment of healing of the graft-host junction was done using ASOCT.

RESULTS

A total of 15 patients (8 men and 7 women) underwent T-FALK. Six patients had superficial corneal opacities after healed microbial keratitis, 5 patients had spheroidal corneal degeneration, 3 patients had Salzman nodular degeneration, and 1 patient had vortex keratopathy. No intraoperative or postoperative complications were noted during T-FALK. All patients had good graft-host junction apposition postoperatively, as demonstrated by ASOCT.

CONCLUSIONS

Sutureless and glue-less T-FALK can be the best way ahead for management of superficial anterior corneal scars with good visual outcome.

Multimodal Imaging in Susac Syndrome: A Case Report and Literature Review

Susac syndrome (SS) is a rare microangiopathy that involves arterioles of the brain, retina, and cochlea. Diagnosis is extremely difficult because of the rarity of the disease and because the signs and symptoms often occur at different times. Multidisciplinary approaches and multimodal images are mandatory for diagnosis and prompt therapy. In this report, we describe a case of SS and the application of multimodal retinal imaging to evaluate the ophthalmologic changes and to confirm diagnosis. Early diagnosis and therapy based on the associations of steroids and immunosuppressants are necessary to limit the sequelae of the disease.

Sutureless Femtosecond Laser-Assisted Anterior Lamellar Keratoplasty Using a Bioengineered Cornea as a Viable Alternative to Human Donor Transplantation for Superficial Corneal Opacities

PURPOSE

To evaluate the safety and efficacy of a bioengineered corneal implant using femtosecond laser-assisted anterior lamellar keratoplasty for superficial corneal opacities.

METHODS

Six eyes of 6 consecutive patients with superficial corneal stromal opacities involving <220 μm owing to various pathologies were included in the study. Preoperatively, all patients underwent anterior segment optical coherence tomography (Visante; Carl Zeiss Meditec AG) to evaluate the depth of the corneal opacity. All patients underwent sutureless femtosecond laser-assisted anterior lamellar keratoplasty using a bioengineered collagen corneal implant (linkcor). Visual indices, refraction, and keratometry were evaluated preoperatively and 12 months postoperatively.

RESULTS

Corrected distance visual acuity improved significantly in all patients (P = 0.02). A significant decrease was seen in refractive astigmatism postoperatively (P = 0.04). Flat keratometry reduced significantly 12 months after the intervention (P = 0.04). No intraoperative or early postoperative complications were noticed. All implants were fully covered by healthy epithelium within a month after the surgery and remained clear at follow-up visits. The results of this procedure remained stable throughout the follow-up period. In 1 patient, mild inferior collagen melting and epithelial defect formation occurred at 1-year follow-up. Despite frequent topical corticosteroid therapy the melting progressed, the collagen tissue was removed and the patient was treated accordingly with good visual outcomes.

CONCLUSIONS

Femtosecond laser-assisted anterior lamellar keratoplasty with bioengineered corneal (linkcor) implantation is an effective treatment for improving vision quality in anterior stromal opacities. This procedure reduces the need for human donor tissue and avoids human donor-related and suturing complications.

Refractive outcome of keratoconus treated by big-bubble deep anterior lamellar keratoplasty in pediatric patients: two-year follow-up comparison between mechanical trephine and femtosecond laser assisted techniques

Background

To evaluate refractive outcome 24 months after Deep Anterior Lamellar Keratoplasty (DALK) in pediatric patients by comparing results achieved using mechanical trephine and femtosecond laser.

Methods

Twenty eyes of 20 patients affected by keratoconus were evaluated. To perform big-bubble DALK, 10 eyes (Group 1; mean age 11.2 ± 2.2 years) were subjected to the Hessburg-Barron mechanical trephine and the remaining 10 eyes (Group 2; mean age 11.3 ± 3.1 years) to a 150 kHz femtosecond laser that performed mushroom incisions. Preoperative thinnest point in the corneal thickness map and K readings were measured by the Sirius Scheimpflug camera. We also evaluated corrected distance visual acuity (CDVA) as logMAR value using spectacles, spherical equivalent and refractive astigmatism.

Results

Mean preoperative thinnest point and pre- and post-operative K readings did not show significant difference (P > 0.05) between the two groups. CDVA, spherical equivalent and refractive astigmatism were respectively, 0.14 ± 0.08 logMAR and 0.13 ± 0.10 logMAR (P = 0.8), − 4.2 ± 1.1 D and − 2.8 ± 1.2 D (P = 0.03), 4.4 ± 2.0 D and 3.6 ± 1.2 D (P = 0.4) in Groups 1 and 2. All DALK procedures were uneventful.

Conclusion

Our findings suggest that femtosecond laser compared to mechanical trephine could significantly reduce the spherical equivalent amount in pediatric big-bubble DALK.

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.

One-stage femtolaser-assisted lamellar keratoplasty and foreign body removal

PURPOSE

To report the use of femtosecond laser platform to remove a glass foreign body (FB) and remove scar by performing sutureless lamellar keratoplasty.

CASE REPORT

A 34-year-old man presented with a posttraumatic anterior stromal scar and retained corneal glass FB after injury to his left eye, sustained in a prior vehicular accident. Right eye examination was essentially normal. Best-corrected visual acuity of the left eye was 20/320. He underwent femtosecond laser-assisted sutureless anterior lamellar keratoplasty using the 500-kHz femtosecond laser machine. The host bed and donor lenticule diameters were 7.9 and 7.8 mm and the thickness of the lenticule was 125 and 150 μm, respectively. The recipient lenticule was obtained by placing the lamellar incision that encompassed the FB. When the recipient lenticule was lifted, partially embedded FB present in the stroma was removed after dislodging it with a 26-gauge needle. The femtosecond-dissected donor button was placed onto the stromal bed with a snug fit. No sutures were taken. Postoperatively, best-corrected visual acuity improved to 20/50 at 1 month and 20/30 at 7 months of follow-up.

CONCLUSIONS

Femtosecond laser-assisted sutureless anterior lamellar keratoplasty is a promising modality for lamellar keratoplasty, and as the depth of the incision can be obtained with precision, impacted stromal FBs can be removed in a single procedure along with scars.

Femtosecond laser-assisted anterior lamellar keratoplasty for the treatment of stromal corneal pathology

BACKGROUND

To describe the initial outcomes and safety of anterior lamellar keratoplasty (ALK) assisted by a femtosecond laser for stromal corneal pathology.

METHODS

A non-comparative case series of 14 eyes (13 patients) with various stromal corneal diseases underwent ALK with a femtosecond laser. Femtosecond laser settings, technique, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and endothelial cell density (ECD) were measured.

RESULTS

All eyes were successfully treated without intraoperative complications. The UCVA improved in 11 eyes (78.6%) compared with preoperative UCVA. The mean difference between preoperative and postoperative UCVA was a gain of 1.7 lines (range, unchanged to 6 lines). The BCVA improved in all eyes compared with preoperative levels. The mean difference between preoperative and postoperative BCVA was a gain of 2.4 lines (range, 1-8 lines). In 3 eyes, phototherapeutic keratectomy was performed. The mean reduction in endothelial cell density was 3.7% after a mean 7.3 months of follow-up. No graft rejection, infection, or epithelial ingrowth was found.

CONCLUSIONS

Femtosecond laser-assisted ALK improved UCVA and BCVA in patients with stromal corneal pathology. Our early results indicated that the femtosecond laser produced an effective and smooth dissection through opaque corneas even deeper corneal tissue.

Femtosecond laser-assisted sutureless anterior lamellar keratoplasty for superficial corneal opacities

PURPOSE

To evaluate the visual and refractive outcomes, endothelial cell count (ECC), ocular surface changes, corneal aberrations, and biomechanical profile changes after femtosecond laser-assisted anterior lamellar keratoplasty surgery for superficial corneal scars.

SETTING

Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.

DESIGN

Prospective case series.

METHODS

Patients with superficial corneal scars had femtosecond laser-assisted anterior lamellar keratoplasty. Visual and refractive results, ECC, ocular surface changes, corneal aberrations, and biomechanical profiles were assessed preoperatively and for 1 year postoperatively.

RESULTS

Nineteen eyes (19 patients) were evaluated. A significant decline occurred in refractive astigmatism and corneal astigmatism after 1 year. There was a nonsignificant reduction in corneal hysteresis and the corneal resistance factor from preoperatively to 1 year postoperatively. The corneal-compensated intraocular pressure (IOP) and Goldmann-correlated IOP increased during the follow-up; the increase was not significant. A statistically insignificant reduction in the root mean square for trefoil and spherical aberrations occurred between 1 month and 1 year postoperatively (P=.1 and P=.4, respectively). The decreases in primary coma and total higher-order aberrations approached significance (P=.08 and P=.07, respectively). There were no significant changes in the central corneal thickness, ECC, or ocular surface parameters. No intraoperative complications occurred.

CONCLUSION

Femtosecond laser-assisted anterior lamellar keratoplasty was an efficient and safe procedure for improving the quality of vision in patients with anterior corneal pathology, and the results remained stable during the 1-year follow-up.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.