Deep anterior lamellar keratoplasty in eyes previously treated with collagen crosslinking for keratoconus: 3-year results

Graefe's Archive for Clinical and Experimental Ophthalmology - To evaluate the 3-year results of deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in keratoconus...     

Corneal endothelium after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus: a four-year comparative study

Purpose:

To compare the status of corneal endothelium and central corneal thickness within the first four postoperative years after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus.

Materials and Methods:

Thirty-nine eyes (Group A) which had PK and 44 eyes (Group B) which had DALK for the treatment of keratoconus were included in this retrospective study. The endothelial cell density (ECD), the mean endothelial cell area and the coefficient of variation of cell area were assessed with a non-contact specular microscope, and the central corneal thickness (CCT) was measured with an ultrasound pachymeter.

Results:

Mean ECD loss rate at two years was 36.24% in Group A and 18.12% in Group B (P<0.001). Mean ECD loss rate at four years was 47.82% in Group A and 21.62% in Group B (P<0.001). Mean annual ECD loss rate was calculated 14.12% per year in Group A and 5.78% per year in Group B. In the PK group, increase in mean CCT was 15.60% in two years and 15.03% in four years, while in the DALK group, mean CCT increased by 8.05% in two years and 9.31% in four years.

Conclusions:

As the majority of ectatic disorders such as keratoconus occur in young people, long-term endothelial cell survival following treatment with keratoplasty is essential for the long-term visual ability. Our finding that corneal endothelial cell loss in the DALK group occurs at a slower rate than in the PK group suggests DALK as a safer alternative to PK in these selected patients.     

The effect of adjunctive Mitomycin C in Ahmed glaucoma valve implantation

PURPOSE: To evaluate the effectiveness and safety of adjunctive mitomycin C (MMC) in Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. METHODS: Twenty-two eyes of 22 patients who underwent AGV implantation with adjunctive MMC (0.5 mg/ml) for 3 minutes (Group A) were compared to a control group of 26 eyes of 26 patients (Group B) who received AGV implantation without MMC. Nine patients were female and 13 patients were male in Group A and 11 patients were female and 15 patients were male in Group B. The mean age was 56 years ranging from 13 to 77 in Group A and 58 ranging from 14 to 71 years in Group B. Success was defined as an intraocular pressure (IOP) between 4 and 21 mmHg with or without glaucoma medication and with no additional glaucoma surgery, phthisis, or loss of light perception. RESULTS: The probability of success at 1 year was 86.36% and 80.76% in Group A and Group B, respectively. The number of glaucoma medications decreased from 2.82 to 0.56 in Group A and from 2.65 to 0.73 in Group B. Postoperative hypotony as an early complication was higher in Group A (31.81% in Group A and 15.38% in Group B). As a late postoperative complication, tube exposure developed in 3 patients (13.63%) in Group A and no such complication was seen in Group B. There was no statistically significant difference in success and complication rates between the two groups (p>0.05). CONCLUSIONS: Although adjunctive MMC in AGV implantation is safe and effective, it may not offer a better chance of surgical success compared with AGV implantation without MMC.