Objective: To investigate the role of ICRS in halting keratoconus progression in a large sample of patients. Methods: A retrospective, non-comparative, interventional study based on the review of medical records of patients diagnosed with keratoconus who underwent Ferrara corneal ring segment implantation. A retrospective chart analysis study of 123 operated eyes with follow-up ranging from 3 to 16 years (mean 5.3 ± 3.6 years) was performed. This study was carried out at Ocular Surgery Unit, São Paulo, Brazil. All topographic data were obtained from Pentacam (Oculus, Arlington, USA). The same surgeon performed all surgeries, and the Ferrara ICRS nomogram was used for ICRS selection in all cases. Results: Corrected distance visual acuity, keratometry, and topographic astigmatism improved in most cases, with statistical significance. In 42 eyes (53.8%), there was an increase in K1 or K2, and in 36 (46.2%), there was a reduction or maintenance in K1. Considering a difference higher than 1 D, between 3-month post-surgery and final visit (group 3), 32 eyes (41%) showed an increase, and 46 eyes (59%) ended equal or below this value. Conclusion: The implantation of ICRS showed improvement in visual and keratometric indexes. The majority of patients did not increase more than one diopter in keratometric values after ICRS implantation. ICRS may be effective for slowing disease progression, especially in older patients.

Purpose: To compare clinical outcomes after implantation of TECNIS Synergy (ZFR00V) intraocular lenses (IOLs) in both eyes and implantation of the TECNIS Synergy and TECNIS Eyhance (ICB00) combination in patients undergoing cataract surgery. Setting: Department of Cataract, Hospital Oftalmológico de Brasilia (HOB), Brasília, Brazil. Design: Prospective, interventional, randomized, parallel-group study. Methods: Patients were categorized into 2 groups: Group 1: ZFR00V IOL was implanted in both eyes. Group 2: An ICB00 IOL was implanted in the dominant eye, and a ZFR00V IOL was implanted in the nondominant eye. Results: Visual acuity was similar between the 2 groups (95% CI <0.1 logMAR). A superior visual acuity of ≥ 20/25 (at −2.00 to −2.50 diopters [D]) was achieved in Group 1 (bilateral ZFR00V) than in Group 2 (combination of ZFR00V/ICB00). The binocular defocus curve demonstrated better visual acuity at 40 cm (−2.00 D) and 50 cm (−2.50 D) in Group 1 than in Group 2 (P < .05). Similar contrast sensitivity values were observed between the 2 groups. Patients in Group 1 reported higher satisfaction (completely satisfied) than those in Group 2 (P < .05). However, halos and glare were more pronounced in Group 1 than in Group 2 (P < .05). Conclusions: Both presbyopia-correcting IOL combinations showed similar binocular visual acuity results. Group 1 demonstrated enhanced visual acuity in the defocus curve at 40 cm (−2.00 D) and 50 cm (−2.50 D). Comparable contrast sensitivity outcomes were observed in both groups. Patients were more completely satisfied in Group 1 than in Group 2, despite the higher frequency of postoperative nighttime halos and glare.

The point of centration for refractive surgery is a theme of great importance that generates considerable discussion among specialists and surgeons in the field. Notably, any changes in light can alter the size of the pupil, and the visual axis of the fixation line to the fovea is unique in each patient. A variety of options have been described in the literature with respect to centration in refractive surgery, and the results differ among these methods. No consensus has been established regarding the ideal refractive surgery technique for evaluation of centration in each patient that will yield a satisfactory surgical result.

Purpose: To compare the differences between the apparent and actual chord µ. Methods: In this prospective, comparative, non-randomized, and non-interventional study, imaging examinations using Pentacam and the HD Analyzer were performed in the same room under the same scotopic conditions. The inclusion criteria were patients aged 21-71 years, able to provide informed consent, myopia up to 4D, and anterior topographic astigmatism up to 1D. Patients using contact lenses, those with previous eye diseases or surgeries, corneal opacities, corneal tomographic changes, or suspected keratoconus were excluded. Results: Altogether, 116 eyes of 58 patients were analyzed. The patients’ mean age was 30.69 (±7.85) years. In the correlation analyses, Pearson’s correlation coefficient of 0.647 indicates a moderate positive linear relationship between apparent and actual chord µ. The mean actual and apparent chord µ were 226.21 ± 128.53 and 278.66 ± 123.90 µm, respectively, with a mean difference of 52.45 µm (p=0.01). The analysis of mean pupillary diameter resulted in 5.76 mm using the HD Analyzer and 3.31 mm using the Pentacam. Conclusions: We found a correlation between the two measurement devices, and even though we found considerable differences, both can be used in daily practice. Given their differences, we should respect their peculiarities as well.

Objective: Evaluation of central corneal densitometry changes following Ferrara corneal ring segment implantation in patients with keratoconus, especially the correlation between corneal densitometry and keratometry. Methods: Retrospective, non-comparative, interventional study based on the review of medical records of patients diagnosed with keratoconus who underwent Ferrara corneal ring segment implantation. Pre and post-operative corneal densitometry measurements obtained with Pentacam HR (Oculus, Wetzlar, Germany) were analyzed. The follow-up time was 3 months, and data comparison was made, using specific statistical analysis, with the data of 3 months postoperatively. Results: The study sample consisted of 43 eyes of 36 patients. The mean corrected visual acuity improved from 0.82 LogMAR preoperatively (SD ± 0.33) to 0.19 LogMAR (SD ± 0.13) postoperatively. The mean spherical equivalent varied from −4.63 (SD ± 3.94) preoperatively to −2.16 (SD ± 2.63) postoperatively. Asphericity varied from −0.69 (SD ± 0.32) preoperatively to −0.27 (SD ± 0.31) postoperatively. The mean maximum K was 54.01D (SD ± 3.38) preoperatively and 51.50D (SD ± 2.90) postoperatively. The mean anterior densitometric value was 18.26 (SD ± 2.03) preoperatively and 17.66 (SD ± 1.84) postoperatively. Conclusion: Corneal densitometry is an interesting technology that should be studied in keratoconus patients. Our results suggest that the corneal densitometry in the cornea’s anterior layer reduces after ICRS implantation and correlates with corneal keratometry. Further studies should be performed to increase the knowledge in this field.