Femtosecond Laser-Assisted Keratolimbal Allograft Transplantation for the Treatment of Total Limbal Stem Cell Deficiency

A New Technique for Harvesting Limbal Stem Cell Tissue for Transplantation Using an Automated Microkeratome and a Novel Globe-Fixation System

PURPOSE

To introduce an unprecedented technique, instrumentation, and setup for the superficial limbus harvest from the human cadaver donor whole globe.

METHODS

We studied several superficial limbus harvest alternatives, developed a preferred approach with our available instruments, and optimized it on a handful of (seropositive) cadaver donors of whole globes.

RESULTS/TECHNIQUE

The globe was pressurized to about normal intraocular pressure by viscoelastic injection through the optic nerve stump. The globe was then mounted on a dynamic globe fixator that maintained a negative pressure in its stabilizing socket. Exertion of the negative pressure effectively elevated globe intraocular pressure (to over 40 mm Hg) and made the corneoscleral wall tight. The socket was then held tilted to the left side for about 35 to 40 degrees to put the limbal zone horizontally and mildly "chin-up." Next, the microkeratome was put on the uppermost and exposed limbus of the globe and activated, and the socket was rotated clockwise under the microkeratome head and its oscillating blade, allowing an effective 360-degree revolution of the microkeratome head around the limbal belt (for a right-handed operator and a counterclockwise cut).

CONCLUSIONS

We consistently succeeded in peeling intact 360-degree strips of the smooth superficial limbus by using blades with varying depths. Our method can be further equipped and optimized and be used by the eye banks and the surgeons for keratolimbal grafting as a more efficient limbal stem cell tissue harvest technique.

The outcomes of corneal sight rehabilitating surgery in Stevens-Johnson syndrome: case series

PURPOSE

To summarize the outcomes of corneal sight rehabilitating surgery in Stevens-Johnson syndrome (SJS).

METHODS

This is a retrospective analysis of a consecutive case series. Twenty-four eyes of 18 SJS patients were included in this study. The ocular parameters, surgical procedures, postoperative complications, and additional treatments of the cases were reviewed.

RESULTS

A total of 29 corneal sight rehabilitating surgeries, which consists of 9 keratoplasties, 8 Keratolimbal allograft (KLAL) and 12 combined surgeries (keratoplasty and KLAL simultaneously) were performed on the 24 eyes. All patients were treated with glucocorticoid eyedrops and tacrolimus eyedrops for anti-rejection treatment without combining systemic immunosuppression, except two patients who were prescribed prednisone tablets for the management of systemic conditions. The mean follow-up period was 50.6 ± 28.1 months. The optimal visual acuity (VA) (0.74 ± 0.60 logarithm of the minimum angle of resolution [logMAR]) and endpoint VA (1.06 ± 0.82 logMAR) were both significantly better than the preoperative VA (1.96 ± 0.43 logMAR) (95% CI, p = 0.000). 57.1% patients (8/14) were no longer in the low vision spectrum, and 88.9% patients (8/9) were no longer blind. The mean epithelialization time was 7.1 ± 7.6 weeks. The success rate was 86.7%. Additional treatments for improving epithelialization included administration of serum eyedrops (n = 10), contact lens (n = 15), amniotic membrane transplantation (n = 6), and tarsorrhaphy (n = 8). Complications included delayed epithelialization (n = 4, over 12 weeks), glaucoma (n = 11), and severe allograft opacity (n = 4). Only one graft rejection was observed.

CONCLUSIONS

Keratoplasty and KLAL can remarkably enhance VA and improve low vision or even eliminate blindness for ocular complications of SJS. The outcome of the surgeries was correlated with the preoperative ocular situation and choice of operative methods.

Topical administration of tacrolimus and corticosteroids in tapering doses is effective in preventing immune rejection in high-risk keratoplasty: a 5-year follow-up study

Background

To evaluate the efficacy of the topical administration of immunosuppressants and corticosteroids in tapering doses in the management of patients with high-risk keratoplasty.

Methods

One hundred and six patients treated with topical immunosuppressants (50 eyes in the FK506 group and 56 eyes in the CsA group) and corticosteroid eye drops in tapering doses were enrolled in the study. The rates of rejection episodes, irreversible rejection, graft survival, and related influential factors were evaluated.

Results

The mean follow-up period was 48.1 ± 7.9 months (range, 36–60 months). The rates of rejection episodes and irreversible rejection were 14.0% and 6.00% in the FK506 group and 37.5% and 7.1% in the CsA group, respectively. Kaplan-Meier survival analysis demonstrated a significantly higher graft survival rate in the FK506 group (81.6%±5.3%, 71.1%±6.3%) compared with that in the CsA group (71.1%±6.3%, 57.5%±7.5%) at 3 and 5 years after surgery (P = 0.006). Multivariate logistic regression revealed that preoperative risk score ≥ 3 (P = 0.016) and endothelial immune rejection (P = 0.033) were risk factors associated with graft survival.

Conclusions

Topical administration of tacrolimus and corticosteroids in tapering doses is effective in decreasing the incidence of immune rejection in high-risk keratoplasty. Careful instruction of patients on the reasonable use of topical tacrolimus is critical to avoid immune rejection induced by sudden discontinuation of medication.

Indications and Surgical Techniques for Repeat Corneal Transplantation in Eastern China: A Twelve-Year Study

Purpose

To analyze the indications and surgical procedures for repeat keratoplasty in eastern China from 2008 to 2019.

Methods

This retrospective descriptive study included 418 eyes of 411 patients who underwent no less than 2 keratoplasties at the Eye, Ear, Nose and Throat Hospital of Fudan University from 2008 to 2019. Medical charts were reviewed. The primary indications for repeat keratoplasty, the reasons for regrafting, and the surgical techniques used in the treatment were collected and analyzed.

Results

Among 418 eyes, 337 eyes (80.6%) had one repeat keratoplasty, and 81 eyes (19.4%) had multiple repeat keratoplasties (≥2 repeat keratoplasties). The median interval between the initial keratoplasty and the first repeat keratoplasty was 25 months, and that between two keratoplasties after the first repeat keratoplasty was 27.5 months. Infectious keratitis was the leading primary indication for single repeat keratoplasty (80 cases, 23.7%) and multiple repeat keratoplasties (19 cases, 23.5%). The second most common primary indication was bullous keratopathy for single repeat keratoplasty (49 eyes, 14.5%) and chemical injury for multiple repeat keratoplasties (14 eyes, 17.3%). The main reason for regrafting was allograft rejection (262 cases, 49.3%), followed by endothelial dysfunction (92 cases, 17.3%), and for vision improvement after tectonic keratoplasty (60 cases, 11.3%). Penetrating keratoplasty (PKP) was the major technique used in repeat keratoplasty (447 cases, 84.2%). However, Descemet stripping endothelial keratoplasty was more frequently used than PKP (72.4% vs. 27.6%, P < 0.001) in the treatment of failed endothelial keratoplasty.

Conclusion

Infectious keratitis was still the leading cause of repeat keratoplasty in eastern China. Although PKP remains the major technique of repeat keratoplasty, the application of customized lamellar keratoplasty has greatly expanded in the last decade. Cautious selection of indications, surgical techniques, and timing for surgery is crucial for a good prognosis after repeat keratoplasty.