[Pre-descement membrane endothelial keratoplasty for treatment of patients with corneal endothelial decompensation]

Objective: To investigate the clinical outcomes of Pre-descement membrane endothelial keratoplasty (PDEK) for treatment of patients with corneal endothelial decompensation. Methods: Retrospective study of case series. The cases of 20 patients (20 eyes) who were diagnosed with corneal endothelial decompensation induced by various original diseases and received PDEK during July 2016 and December 2016 at Zhongshan Ophthalmic Center have been analyzed. The participants included 8 males and 12 females with an average age of (59.3±11.8) years. All 20 patients received PDEK operation, the Dua's layer, descement membrane and endothelium of donor tissue were separated from the underlying stroma with the application of big-bubble technique, and donor discs with diameters of 7.75 or 8.00 mm were harvested with scissors. The donor discs were stained with 0.06% trypan blue and loaded on inserters which were then gently inserted into the anterior chamber of the recipient. When the rolled inserted graft was unfolded, air was carefully injected into the anterior chamber underneath the graft so that the graft can attach to the stroma of the recipient. Post-operation follow-ups of over 6 months have been conducted for all patients, the best spectacle corrected visual acuity (BSCVA), the position of donor disc, corneal thickness and corneal endothelial cell density (ECD) were documented. The pre-operation and post-operation (6 months postoperatively) corneal thickness data of the patients were analyzed with paired sample t test. Results: The success rate of preparing PDMEK donor disc with big-bubble technique is 90% (18/20). Eighteen patients (90%) received PDMEK surgery successfully. Anterior segment optical coherence tomography (AS-OCT) results indicated that sixteen donor discs (16/18) were well attached to the back surface of the recipient stroma, and that two discs (2/18) dislocated at 6 days after surgery. At 6 months post-operatively, the corneas of 14 patients (14/18) turned clear with their BSCVA ranging 0.4 to 1.0, and the ECD was (1 389.3±373.2) cells/mm(2) for the patients with clear corneas. At 6 months post-operatively, the average corneal thickness of the patients reduced to (605±45) μm from the preoperative level of (655±56) μm, and the differences are of statistical significance (t=2.137, P=0.032). Conclusions: Application of big-bubble technique could effectively secure the success rate of PDEK disc preparation and control the loss of donated corneas. PDEK disc can be easily handled and unrolled in the anterior chamber, which could improve the postoperative clinical outcomes. (Chin J Ophthalmol, 2018, 54: 105-110).