[Surgical technique of keratoplasty with simultaneous implantation of a continuous ring or ring segment into the graft]. / Khirurgicheskaya tekhnika keratoplastiki s odnomomentnoi implantatsiei tsel'nogo ili razomknutogo kol'tsa v transplantat.

The article presents the surgical technique of penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) with femtosecond-laser assistance involving simultaneous implantation of an intracorneal continuous ring (ICCR) or an intracorneal ring segment (ICRS) into the graft. Surgical technique no. 1 - keratoplasty with simultaneous implantation of ICRS. Intrastromal circular tunnel is formed in the central zone of donor cornea using femtosecond laser. Then penetrating trepanation 8.1 mm in diameter is performed symmetrically to the formed tunnel. After preparing penetrating or lamellar recipient bed, suture fixation is placed in the corneal transplant, then the ICRS is implanted into the graft. Surgical technique no. 2 - keratoplasty with simultaneous implantation of ICCR. The donor cornea is dissected from periphery to center using femtosecond laser. Central zone remains untouched. A large diameter full-thickness trepanation is performed and the donor cornea is divided into the anterior and posterior layers. The ICCR is put on the donor cornea while holding the posterior layer with forceps. Penetrating or lamellar recipient bed is prepared, then the corneal graft is fixed with sutures. Transparent corneal graft acceptance does not guarantee high visual acuity due to post-keratoplasty astigmatism. Surgical correction of astigmatism is performed in the long term post-operatively and isn't effective enough. We proposed this new surgical technique of keratoplasty with simultaneous implantation of ICCR and ICRS into the graft as close as possible to the visual axis of the eye, which can help make the postoperative astigmatism minimal both immediately after surgery and in the long term. The study proposes a new approach to intraoperative prevention of post-keratoplasty astigmatism. The technique is simple, safe and effective. Analysis of long-term outcomes is required before recommending this method for widespread use in clinical practice.

[A new surgical approach to pre-Descemet's endothelial keratoplasty]. / Novyi khirurgicheskii podkhod k predestsemetovoi endotelial'noi keratoplastike (PDEK).

PURPOSE: The study aimed to develop new surgical methods of obtaining and preserving pre-Descemet's endothelial keratoplasty (PDEK) graft in order to reduce the loss of donor material. MATERIAL AND METHODS: The study was conducted on 30 sclerocorneal discs, which were divided into three groups. The first group consisted of 10 sclerocorneal discs to which the standard PDEK graft preparation technique was applied. The second group consisted of 10 sclerocorneal discs, where the PDEK graft preparation was done using the optimized method 1 involving the KD Ring fixator, KD Base for PDEK, KD-30G needle with 5 mL syringe connected to the spring-load plunger, a preservative solution. The third group consisted of 10 sclerocorneal discs with PDEK graft prepared using the optimized method 2, which differed from the optimized method 1 in additional use of the KD artificial chamber for PDEK. When successfully acquiring the type-1 "big bubble", the dissected PDEK graft was preserved for further use in clinical practice using our own technique. RESULTS: In the first group, formation of the type-1 «big bubble¼ was achieved only in 5 out of 10 donor corneas (50%). Bubble ruptures happened in 4 cases (40%) and type-2 «big bubble¼ occurred in 1 case (10%). In the second group (optimized method 1) the type-1 «big bubble¼ was achieved in 9 cases (90%), while in the third group (optimized method 2) the type-1 «big bubble¼ was achieved in 10 cases (100%), proving the effectiveness of our PDEK graft preparation technique. CONCLUSION: We presented a novel surgical approach for acquiring and preserving PDEK graft that minimizes almost all the difficulties that surgeons face, including bubble rupture during pneumodissection and hydrodissection, formation of type-2 and mixed type bubble, and obtaining a PDEK graft of the required size; the details of the surgical technique have been refined. The proposed technique for graft preparation and preservation can be easily implemented in eye banks and is convenient for clinical practice.