Preparation of the Donor Tissue

The donor tissues stored in McCarey–Kaufman medium were obtained from the Eye Bank of Peking University Third Hospital and were evaluated for suitability for DSEK. The donor graft dissection was performed with a Moria CB microkeratome (head 350-400 μm blade depth; Moria Surgical, Doylestown, Pennsylvania, USA) in 26 eyes and manually using a Moria ALTK artificial anterior chamber (Moria Surgical) in 4 eyes because of the flexible characteristics of the tissues of pediatric donors <2 years of age. The donor tissues were prepared by the surgeon immediately before surgery, and the dissected buttons were stored in McCarey–Kaufman medium during the surgical interim.

Preparation of the Recipient Bed

All surgeries were performed under general anesthesia. A circular mark with a diameter of 7.5 or 8.0 mm was made on the anterior corneal surface to delineate where to strip the DM. A main scleral tunnel was made at the 12 o’clock position. Using Healon GV (Abbott Medical Optics, Abbott Park, Illinois, USA) to maintain the anterior chamber, scoring of DM with a reverse Terry–Sinskey hook (Bausch and Lomb Surgical, St. Louis, Missouri, USA) and scraping of the recipient bed with a Terry Scraper (Bausch and Lomb Surgical) were performed. All DM specimens were sent for pathological analysis.

Donor Lenticule Insertion

Because of the phakic status of all patients, pilocarpine was applied preoperatively to protect the transparent crystalline lenses, and the donor lenticule was inserted into the anterior chamber using a suture-assisted donor lenticule insertion technique to minimize manipulations in the anterior chamber. The donor lenticule overlying a bed of cohesive viscoelastic was carefully folded and pulled into Busin’s glide (Moria Surgical) with forceps, and a 10-0 prolene suture was fixed at the 6 o’clock position as an anchoring stitch. The anchoring stitch was tied to create a loop, after which it was placed in the anterior chamber and pulled through the incision in the 6 o’clock direction with a hook. After evacuation of all the viscoelastic material, an anterior chamber maintainer was inserted through the temporal incision to provide irrigation. The donor lenticule was pulled into the anterior chamber through the main scleral tunnel at the 12 o’clock position with the assistant of Busin’s glide and the anchoring stitch. Once inserted, the donor lenticule was unfolded in balanced salt solution (BSS, Alcon, Fort Worth, Texas, USA).

To prevent postoperative pupillary block by air bubbles, peripheral iridectomy was performed. The scleral incision was then interrupted sutured with 10-0 prolene sutures. The anchoring stitch was cut after the donor lenticule was positioned and centered. A complete air fill was performed and maintained for 10 minutes, followed by gentle partial release of air to maintain 75% air volume in the anterior chamber. The patient was maintained in the supine position for 4 hours. For children who could not cooperate, postoperative sedation was provided by an anesthesiologist.

Postoperative Management

Postoperatively, topical drops including 1% prednisolone acetate, tobramycin (Tobrex, Alcon Laboratories, Inc., Fort Worth, Texas, USA), cyclosporin (1%; North China Pharmaceutical Company, Ltd., Shijiazhuang, Hebei Province, China), and artificial tears 4 times daily were prescribed for the first week. The dosages were reduced gradually as clinically indicated and stopped 12 months postsurgery.

Patients were reviewed at 1, 3, 7, and 30 days and at 3, 6, and 12 months postoperatively and once per year thereafter. BCVA was tested at each visit using a logMAR visual chart. For patients who were too young to cooperate for the vison test, whether they could fix and follow (FF) light was checked using a torch. IOP (noncontact tonometer), lenticule status, corneal clarity, and complications were recorded at each visit. Anterior segment optical coherence tomography (Carl Zeiss Meditec, Dublin, California, USA) and endothelial evaluation with confocal microscopy (Heidelberg Engineering, GmBH, Dossenheim, Germany) were performed when possible and appropriate. Sutures were removed within the first month postoperatively. All patients were referred to a pediatric ophthalmologist for amblyopia therapy 1 month after DSEK.