PURPOSE: To compare the predictability of intrastromal tunnel depth creation for intrastromal corneal ring segments (ICRS) implantation between manual dissection and femtosecond laser using a high-resolution anterior segment optical coherence tomography (AS-OCT). METHODS: This multicenter study included patients with keratoconus who had Ferrara-type ICRS implantation at Hospital de Braga using manual dissection and at the Fernandez-Vega Ophthalmological Institute using the femtosecond laser technique. The intended depth of implantation was compared to the achieved postoperative ICRS depth of each case, measured using a swept-source AS-OCT (CASIA SS-1000; Tomey Corporation, Nagoya, Japan) at three points (proximal, central, and distal end of the implant). RESULTS: The study included 105 eyes in the manual group and 53 eyes in the femtosecond laser group. The differences of the intended versus the achieved depth were statistically higher in the manual group for all positions measured (Wilcoxon ranked-sum, P < .001). In the manual group, there were significant differences between the mean values of intended and achieved depth after surgery for the three locations measured (Wilcoxon signed-rank, P < .05), whereas there were no significant differences in the femtosecond laser group. In the manual group, the proximal part of the stromal tunnel was significantly shallower (−40.87 ± 69.03 μ m) than the central (−25.54 ± 71.00 μ m) and distal (−26.52 ± 73.22 μ m) parts (Friedman test, P < .05). CONCLUSIONS: ICRS implantation assisted by a femtosecond laser provides a more precise procedure considering dissection depth when compared with the manual dissection technique. Such an advantage may provide more predictable clinical results and safer procedures with the femtosecond laser. [ J Refract Surg. 2018;34(3):188–194.]

Purpose: To compare the incidence of complications between manual and femtosecond-laser assisted surgery for intrastromal corneal ring segments (ICRS) implantation. Material and methods: This study included keratoconus patients who had ICRS implantation using manual dissection and using the femtosecond laser with a minimum follow-up of 12 months. Uncorrected (UDVA) corrected (CDVA) distance visual acuity (CDVA), refraction, corneal topography and aberrometry, pachymetry map and slit-lamp microscopy were assessed before and after surgery. Results: The study included 265 eyes in the manual group and 111 in the femtosecond laser group. In the manual group, there were complications in 48 eyes (18.11%); while in the femtosecond laser 4 eyes had a complication (3.6%). In the manual group, the most frequent complications were ICRS exchange/adjustment for visual and refractive enhancement (25 eyes; 9.43%) and late ICRS spontaneous extrusion (15 eyes; 5.66%). In the manual group, 81.25% of complications were observed during the first 3 years of surgeon’s experience. Eyes who suffered a complication had preoperatively higher mean refractive (p=0.002) and topographic cylinder (p=0.003) and lower UDVA (p= 0.005) and CDVA (p=0.002). After a second surgical procedure for complication management visual, refractive and topographic outcomes significantly improved. Conclusion: Manual mechanical ICRS surgery shows a higher rate of intra- and postoperative mechanical and refractive complications when compared to femtosecond laser assisted technique. The incidence is specially higher during the surgeon’s first years of implementation of the technique.

Purpose: To evaluate the long-term effectiveness, safety, and stability of Ferrara-type intrastromal corneal ring segments (ICRS) by manual surgery implantation in patients with keratoconus. Setting: Ophthalmology Department, Hospital de Braga, Braga, Portugal. Design: Retrospective cohort study. Methods: This study included 124 eyes that had ICRS implantation using the manual technique with a follow-up of 5 years. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), subjective refraction, keratometry, aberrometry, and pachymetry maps were evaluated preoperatively and at 6 months, 1 year, and 5 years postoperatively. A secondary analysis of all variables was performed comparing 2 subgroups of patients: a group younger than 30 years and a group of 30 years or older. Results: At 5 years, both mean UDVA and CDVA improved significantly (P < .0001) from a preoperative value of 0.91 ± 0.36 to 0.46 ± 0.32 logMAR and 0.40 ± 0.27 to 0.22 ± 0.20 logMAR, respectively. Spherical equivalent, refractive cylinder, and all topography values significantly decreased postoperatively (P < .0001). No regression was observed in any visual or topographic parameter during the entire follow-up. Regarding the subgroup analysis, both younger and older patients demonstrated similar and stable results from the preoperative to the 5-year visit, except for minimum pachymetry value change over time. Conclusions: Ferrara-type ICRS implantation significantly improved visual acuity, refractive error, and topographic values; the improvement was stable throughout a 5-year follow-up period. This study confirms that ICRS implantation surgery for keratoconus is a stable procedure in a long-term follow-up, regardless of the preoperative patient's age.

Purpose: To evaluate the long-term efficacy and safety of iris-fixated foldable phakic intraocular lenses (pIOLs) for the management of myopia and astigmatism after 6-year follow-up. Setting: Ophthalmology Department, Hospital Braga, Portugal. Design: Retrospective cohort study. Methods: Patients included underwent iris-fixated foldable Artiflex pIOL implantation between January 2010 and December 2013. Follow-up evaluations were performed 6 months postoperatively and every 12 months until 72 months. Preoperative and follow-up data on uncorrected and corrected distance visual acuity (CDVA), manifest refraction, endothelial cell density (ECD), and anterior chamber depth (ACD) were analyzed. Results: A total of 177 eyes of 98 patients with a mean age of 32.33 ± 7.13 years were analyzed. There was a statistically significant improvement in CDVA from 0.09 ± 0.02 logMAR preoperatively to 0.04 ± 0.02 logMAR (P < .0001) at 6 years postoperatively. The spherical equivalent demonstrated a statistically significant improvement from −9.50 ± 2.93 diopters (D) to −0.41 ± 0.45 D at 6 years. At 72 months, the efficacy and safety indexes were 0.94 and 1.15, respectively. A mean loss of 31.77 cells/mm² (1.19%) was observed each year until the sixth year. The overall mean ECD loss after correction for the physiological loss was 3.02% after 6 years. No correlations were observed between the mean ECD loss and the preoperative ACD. Conclusions: The Artiflex pIOL was a safe, effective, and a stable option to correct myopia. A mean ECD loss of 3.02% was observed over 6 years. No pIOL was explanted due to corneal decompensation.

PURPOSE: To evaluate the outcomes after topography-guided ablation treatment (T-CAT) for the correction of myopia and myopic astigmatism with photorefractive keratectomy (PRK). METHODS: This was a retrospective, non-comparative case series study of 25 patients (40 eyes) with low to moderate myopia with or without astigmatism who underwent topography-guided custom PRK with the Wave-Light EX500 excimer laser platform (Alcon Laboratories, Inc., Fort Worth, TX). The customized treatment plan was based on Topolyzer Vario topography system (Alcon Laboratories, Inc.) data. The patients were observed for 6 months after the procedure. RESULTS: The surgery significantly reduced the manifest refractive spherical equivalent (MRSE), sphere, and cylinder ( P < .05) at 6 months of follow-up. Compared with the preoperative corrected distance visual acuity (CDVA), 8 (20%) and 10 (25%) of 40 eyes gained one or more lines of postoperative uncorrected distance visual acuity at 3 and 6 months, respectively. Only 1 eye presented loss of one line of CDVA at 6 months postoperatively, which was due to delayed epithelial healing. Ten patients (15 eyes) reported symptoms related to dry eye and the vision of 21 patients (17 eyes) fluctuated during the first month. CONCLUSIONS: The T-CAT custom PRK procedure provided good early outcomes for treating patients with low to moderate myopia with or without astigmatism. [ J Refract Surg. 2018;34(8):541–546.]

Purpose: To evaluate visual, refractive, and corneal topography outcomes in eyes with keratoconus that have undergone exchange/adjustment surgery with a new intrastromal corneal ring segment (ICRS) combination after unsuccessful visual and/or refractive outcomes after primary ICRS surgery. Methods: A retrospective nonrandomized case series was conducted including consecutive eyes of patients with keratoconus that underwent ICRS adjustment after an unsuccessful visual outcome. Patients were divided into 2 groups: group 1 was made up of patients with Intacs ICRSs that were exchanged for the Ferrara ICRS type, and group 2 consisted of patients who maintained the same ICRS type after undergoing ICRS adjustment surgery (change of the arc length or thickness). Uncorrected distance visual acuity, best-corrected distance visual acuity (CDVA), keratometry, asphericity, higher-order aberrations, and corneal regularity indexes (ISV and IHD) (Pentacam HR; OCULUS) were assessed preoperatively and 12 months after each procedure. Results: Twenty-six eyes from 26 patients were included, 8 eyes in group 1 and 18 eyes in group 2. The eyes in both groups improved their CDVA values after ICRS exchange, in group 1 from 0.27 ± 0.11 preoperatively to 0.54 ± 0.17 postoperatively (P = 0.001), and in group 2 from 0.34 ± 0.22 to 0.61 ± 0.15 (P < 0.0001). In both groups, there was also a significant improvement in the refractive cylinder, topographic cylinder, and coma after ICRS adjustment (P < 0.05). Conclusions: ICRS implantation has been shown to be a reversible and adjustable surgical procedure for keratoconus treatment. Good outcomes can be obtained after ICRSs are exchanged.