ABSTRACT
PURPOSE: To evaluate the effectiveness and safety of combined epithelium-off cross-linking (CXL) with photorefractive keratectomy (CXL Plus) for correction of the myopic and astigmatic components of keratoconus. METHODS: Seventy-nine eyes of 46 patients who underwent CXL Plus were enrolled in this retrospective, multicenter, noncomparative clinical study. Uncorrected distance visual acuity, corrected distance visual acuity, refraction, keratometry, and pachymetry measurements were recorded preoperatively and at 3, 6, 12, and 18 months during follow-up. RESULTS: The mean (±SD) preoperative uncorrected distance visual acuity and corrected distance visual acuity were 1.00 ± 0.22 logarithm of the minimum angle of resolution (logMAR) and 0.62 ± 0.38 logMAR, respectively, and improved to 0.71 ± 0.36 logMAR and 0.32 ± 0.18 logMAR postoperatively. The mean k value, mean corneal thickness at the thinnest location, and mean myopic and astigmatic components decreased from 46.58 ± 0.97 D, 473 ± 29 µm, 3.65 ± 1.72 D, and 1.83 ± 0.69 D preoperatively to 43.79 ± 1.17 D, 431 ± 38 µm, 1.02 ± 0.78 D, and 1.15 ± 0.26 D, respectively, during follow-up. Eleven eyes had delayed epithelial healing, 2 had stromal opacities, 1 had primary herpes simplex keratitis, and 5 showed progression of keratoconus. CONCLUSIONS: CXL Plus improved the refractive status of keratoconus during 18 months of follow-up, despite its potential early postoperative complications of delayed epithelial healing and corneal haze. CXL Plus reduced the myopic component more than the astigmatic component of keratoconus. However, the safety and stability of the procedure were offset by longer-term postoperative complications and a high rate of postoperative progression of keratoconus.
Subject(s)
Cross-Linking Reagents , Keratoconus/therapy , Lasers, Excimer/therapeutic use , Photorefractive Keratectomy/methods , Photosensitizing Agents/therapeutic use , Riboflavin/therapeutic use , Adolescent , Adult , Collagen/metabolism , Combined Modality Therapy , Corneal Stroma/metabolism , Female , Humans , Keratoconus/drug therapy , Keratoconus/metabolism , Keratoconus/surgery , Male , Photochemotherapy/methods , Refraction, Ocular/physiology , Retrospective Studies , Treatment Outcome , Ultraviolet Rays , Visual Acuity/physiology , Young AdultABSTRACT
PURPOSE: To analyze the results of three-year outcomes of combined epithelium-on cross-linking with femtosecond laser ICRS (cross-linking PLUS) for keratoconus management. DESIGN: A retrospective multicenter clinical study. METHODS: 43 eyes of 38 patients were subjected to preoperative and postoperative UCVA, BCVA, refraction, Pentacam pachymetry, and keratometry examinations at 3-, 6-, 12-, 24-, and 36-month follow-up period. RESULTS: The preoperative and postoperative mean UCVA was 1.30 ± 0.48 (logMAR ± SD) and 0.82 ± 0.22 respectively. The preoperative and postoperative mean BCVA was 0.90 ± 0.40 and 0.60 ± 0.30, respectively. The preoperative and postoperative mean K average was 50.63 ± 0.87 (D ± SD) and 45.56 ± 0.98, respectively. The preoperative and postoperative mean pachymetry was 471 ± 92.36 (µm ± SD) and 423 ± 39.58, respectively. The preoperative and postoperative mean astigmatism was 7.55 ± 1.75 and 3.39 ± 1.26, respectively. One eye showed ICRS edge exposure while 6 eyes showed progression of keratoconus. CONCLUSION: CXL PLUS was proved to be a successful procedure to halt progression (mainly by CXL) and to correct the refractive status of the keratoconic eye (mainly by ICRS). CXL PLUS performed a synergistic action correcting and maintaining the correction of both myopic and astigmatic components of keratoconus.
ABSTRACT
PURPOSE: To evaluate the use of a human fibrin tissue adhesive in the adherence of corneal lamellar flaps in rabbit eyes. METHODS: Corneal flaps were made using a microkeratome in both eyes of six New Zealand white rabbits. In the right eyes, the flaps were glued with fibrin tissue adhesive; in the left eyes, flaps were allowed to heal without adhesive (controls). All eyes were treated with antibiotics and steroids once daily for 10 days. Slit-lamp biomicroscopy was performed 1 and 10 days after surgery. The rabbits with surviving flaps were euthanized and the corneas obtained for histopathologic examination 10 days after surgery. RESULTS: Slit-lamp examinations showed no interface deposits and no other signs of corneal toxicity. Histologically, a few inflammatory cells were seen in both the experimental and control eyes, and microscopic gapping and tissue debris were observed in three of the six control eyes. CONCLUSIONS: Human fibrin tissue glue was well tolerated in these eyes, with no or minimal corneal toxicity. Further studies are needed to determine the tensile strength of the adhesive bond in the cornea.
