Clinical, tomographic, and topometric outcomes of progressive thickness intracorneal ring segment implantations in duck-type keratoconus

Purpose: To evaluate the visual, refractive, tomographic, and topometric outcomes of progressive thickness intracorneal ring segment (PT-ICRS) implantation in duck-type keratoconus. Methods: This retrospective study included eyes with oval (duck-type) keratoconus treated with PT-ICRS implantation. After the femtosecond laser tunnel creation, one PT-ICRS (Keraring AS 5 with 160° arc length) was implanted along the ectatic, inferior half of the cornea. Data of uncorrected and corrected distance visual acuity (UDVA and CDVA), refraction, asphericity (Q value), and keratometry (K) were compared pre- and postoperatively. Additionally, changes in the topometric indices of corneal irregularity were also evaluated after PT-ICRS implantation. Results: Thirty-one eyes of 30 patients were included in the study with a mean follow-up time of 9.06 months (ranging between 6 and 18 months). UDVA improved from 0.85 ± 0.36 to 0.27 ± 0.14 logMAR (P = 0.001), and CDVA improved from 0.37 ± 0.22 to 0.13 ± 0.11 logMAR (P = 0.001). The mean spherical error decreased from ?3.66 ± 2.60 to ?1.60 ± 1.42 D (P = 0.001), and the mean cylindrical error decreased from ?4.91 ± 2.65 to ? 1.41 ± 1.31 D (P = 0.001). All topographic parameters measured from the anterior cornea demonstrated statistically significant improvements after PT-ICRS implantation (P = 0.001). K mean, K maximum, corneal astigmatism, and Q value showed a significant decrease. Besides the index of height asymmetry, all topometric indices were significantly reduced after PT-ICRS implantation. There were no loss of lines and no complications. Conclusion: PT-ICRS implantation in duck-type keratoconus is an effective and safe treatment. This intervention improves the visual acuity, refractive error, topographical, and topometric parameters significantly by decreasing both eccentricity and steepness of the cone.

A Case of Fungal Keratitis after Intracorneal Ring Segment Implantation for Keratoconus

PURPOSE: To report a case of fungal keratitis 3 days after intracorneal ring segment (ICRS) implantation for keratoconus. CASE SUMMARY: A 65-year-old woman was referred to our clinic with refractory infectious keratitis in her left eye 3 days after ICRS insertion for keratoconus. Slit lamp examinations revealed infiltrates around the incision site with cellular reaction in the anterior chamber after the ICRS had been removed. Corneal scrapings were obtained for staining and cultures, and intensive topical antibiotics were administered. Initial microscopy and cultures were negative. Despite the use of intensive topical antibiotics, there was no improvement. Hyphae were isolated from additional corneal scrapings. The patient's symptoms and corneal findings improved following administration of topical amphotericin B and oral itraconazole. CONCLUSIONS: Infectious keratitis after ICRS implantation is an uncommon but sight-threatening complication. Fungal keratitis should also be considered if infectious keratitis after ICRS is unresponsive to antibiotics.

Intracorneal Ring Segment Implantation for the Management of Keratoconus: Short-Term Safety and Efficacy

PURPOSE: To assess the safety and efficacy of intracorneal ring segment (Intacs ring) implantation in managing keratoconus. METHODS: This retrospective case series comprised of 11 keratoconic eyes (11 patients) had Intacs ring (Addition Technology, Inc, California, USA) implantation. The main outcome measures were best corrected visual acuity, refraction, keratometry, topography, and pachymetry. Patients were examined before Intacs ring implantation as well as one week, one, three, and six months postoperatively. RESULTS: The mean best corrected visual acuity improved from 0.60+/-0.33 logMAR preoperatively to 0.39+/-0.23 logMAR six months postoperatively (p>0.05) and the mean corneal thickness, from 432.82+/-41.17 micrometer preoperatively to 448.00+/-62.27 micrometer at six months (p>0.05). The mean cylinder improved from -5.36+/-2.70D preoperatively to -2.50+/-1.66D six months postoperatively (p<0.05) and the mean keratometry, from 47.99+/-2.38D to 42.83+/-1.72D at six months (p<0.05). In addition, the mean spherical equivalent improved from -6.64+/-3.49D preoperatively to -3.66+/-3.37D six months postoperatively (p<0.05). One eye had a risk of ring exposure, but the others had no significant complications. CONCLUSIONS: Intacs ring implantation appears to be effective in improving cylinder, spherical equivalent, and keratometry in patients with keratoconus.