Femtoassisted posterior lamellar keratoplasty in bullous keratopathy of stage IV–V (clinical application experience)

BACKGROUND: Bullous keratopathy is a chronic edema of the cornea, accompanied by a significant visual acuity loss and pain. The cause of bullous keratopathy is a pathological irreversible decrease in the number of endothelial cells, in which the endothelial layer cannot perform its main barrier and pumping functions.

AIM: To evaluate the reproducibility and functional results of femto-assisted posterior lamellar keratoplasty using intraoperative OCT at the stage IV–V of bullous keratopathy.

MATERIALS AND METHODS: The study was conducted on 23 eyes of 23 patients diagnosed with stage IV–V of bullous keratopathy. The mean age of patients was 69 ± 12 years, there were 14 male patients and 9 female patients. Before surgery, light perception with correct light projection was recorded in 15 cases, in 5 cases — the count of fingers at the face (0.005), in 3 cases visual acuity was 0.01. The central corneal thickness varied from 981 μm to 1960 μm and averaged 1008 ± 96 μm. Femto LDV Z8 femtosecond laser (Ziemer, Switzerland) was used to form an endothelial graft. All surgeries were performed using the Hi-R Neo 900 operating microscope with an integrated third-generation OCT module (Haag-Streit Surgical, Germany).

RESULTS: No intraoperative complications were noted. The presence of objective control in the form of intraoperative OCT made it possible in all cases to clearly differentiate stromal and endothelial surfaces of the posterior layered graft located in the anterior chamber of the eye. The postoperative course was standard for posterior lamellar keratoplasty, accompanied by resorption of corneal edema with restoration of its transparency. The normalization of corneal thickness was noted by 1 month after surgery, and the restoration of corneal optical properties was noted by 3–6 months and was accompanied by gradual increase in visual acuity. Corrected visual acuity by 1 month was 0.05 ± 0.03, by 3, 6, 12 months — 0.1 ± 0.05, 0.15 ± 0.05 and 0.15 ± 0.04, respectively. By 12 months after surgery, the central corneal thickness was 596 ± 42 μm, the thickness of the ultrathin graft tended to decrease somewhat to 67 ± 8 μm, the loss of endothelial cells was 59.3%. Endothelial graft survival was achieved in 82.6% of cases.

CONCLUSIONS: The use of intraoperative OCT allows expanding the indications for posterior lamellar keratoplasty in bullous keratopathy, including the stage IV–V of the disease.