**2. Methodology**

A retrospective analysis of the records of 120 patients, who underwent PK at the Emam-reza and Vali-asr teaching hospitals of Birjand University during 7- year period from 1999 to 2006, was performed.

All surgeries were performed by one expert surgeon using the same procedure and there were no intra-operative complications. Preoperative examinations consisted of visual acuity, refractive error and slit-lamp examination. Patient's pre-operative information included age, sex, systemic disease, lid abnormalities, pre-existing ocular surface disease and corneal vascularization, surgical indications and preoperative medications. The data of the last examination including uncorrected visual acuity (UCVA), refractive error, intra-ocular Pressure (IOP), graft clarity, any episode of endothelial graft rejection during the follow-up, also, suturing technique and intraoperative complications were recorded.

graft failure and recurrence of MCD in the transplanted cornea were compiled Patients were followed up for a minimum of 2 years .This data were analyzed regarding sex, age, indication, job and location of the patient. Statistical significance was determined using X2 analysis and descriptive statistic measures including percentiles, mean and standard deviation were calculated. Personal information of patients was not disclosed and the data sheets were anonymous.

The donor lenticule was secured to the recipient corneal rim with 10-0 monofilament nylon sutures. The suturing techniques consisted of interrupted (16 separate sutures), single running (with 16 bites), and combined (8 separate sutures and a 16-bite running suture).

At the end of the operation, subconjunctival gentamicin 20 mg and betamethasone 4 mg were injected. Postoperatively, the patients were medicated with topical betamethasone 0.1% and choloramphenicol eye drops four times a day. Antibiotic eye drop was discontinued after 7 to 10 days and betamethasone eye drop was gradually tapered over 4 months.

Selective suture removal was performed for any suture-related problems and for control of astigmatism, based on topography, from four month onward. Suture removal was completed between 12 and 18 months after the date of the surgery. Patients were examined on 1st, 2nd, 3rd and 7th days and then every week up to one month, every 2 weeks up to 2 months, monthly up to 4 months, and every 2 months thereafter. Finally, Two months after complete suture removal, patients were reevaluated.
