Radial keratotomy: background and how to manage these patients nowadays.

In this review, we presented the principles of radial keratotomy (RK), its evolution, enhancement, and complications, and strategies to manage the consequences of RK in the present day. It is essential to understand the RK procedure f, the theoretical background that supported this surgery, the current effect on the cornea, and how to approach patients needing vision improvement. These patients are developing cataracts that need to be handled well, from the IOL calculation to the surgical procedure. Guided keratorefractive surgery is the most accurate procedure to improve these patient's vision and life. Nevertheless, some patients may need other approaches, such as sutures, penetrating keratoplasty, corneal rings, and pinhole implants, depending on the degree of irregularity of the cornea, ablation depth for guided surgery or if the sutures are open.

Comparison of endothelial cell loss in diabetic patients after conventional phacoemulsification and femtosecond laser-assisted cataract surgery.

PURPOSE: This study aims to comparatively evaluate the morphological changes of the cornea after phacoemulsification (PHACO) and femtosecond laser-assisted cataract surgery (FLACS) without intercurrences in patients with type 2 diabetes mellitus. METHODS: A total of 95 diabetic patients with moderate cataracts (N2 + and N3+), 47 undergoing PHACO and 48 undergoing FLACS, were selected randomly for the study. Surgeries were performed by a single surgeon between July 2021 and December 2021. Cumulative dissipated energy (CDE) and total balanced saline solution (BSS) data were obtained at the end of each surgery. Changes in corneal endothelial cell density (ECD) and central corneal thickness (CCT) at three months postoperatively were investigated. RESULTS: After three months, evidence is lacking between groups in the CCT measures; the difference was neither statistically nor clinically relevant. However, for ECD, a significant and clinically significant difference was found; if all patients were treated with laser, the mean ECD would be 423.55 greater (RSE: 86.09; p-value < 0.001; 95% CI: 254.81-592.29) than the ECD potential means of 1656.423 among the conventional group (RSE: 74.90; p-value < 0.001; 95% CI: 1509.62-1803.23). CONCLUSIONS: Diabetic patients under treatment with moderate cataracts may predispose themselves to a more significant loss of endothelial cells after conventional phacoemulsification than femtosecond laser-assisted cataract surgery. TRIAL REGISTRATION: It was registered at The Brazilian Registry of Clinical Trials (ReBEC) with the code RBR-6d8whb5 (UTN code: U1111-1277-6020) on 17/05/2022.

Vision Quality Questionnaire Assessment in Patients After Topography-Guided Photorefractive Keratectomy for Irregular Astigmatism Secondary to Radial Keratotomy.

Aim: To evaluate the vision-related quality of life with the National Eye Institute Refractive Error Quality of Life (NEI-RQL) questionnaire in patients with astigmatism secondary to radial keratotomy surgery who underwent topography-guided photorefractive keratectomy. Methods: Prospective non-randomized clinical trial. This study included 15 patients (30 eyes) aged > 21 years, mean age 55.1 (SD, 3.5) years, 53.3% female, with astigmatism ≤ - 6.00 D resulting from radial keratotomy, which could have been associated with hyperopia ≤ + 6.00 D. Photorefractive keratectomy with topography-guided custom ablation treatment was used in all cases. The patients answered the NEI-RQL questionnaire preoperatively and at 4 and 48 months after topography-guided photorefractive keratectomy. The following data were collected: age, sex and education level, pre-operative refraction data, visual acuity with or without correction, pachymetry, and keratometry. Results: There was a significant difference between pre-and postoperative NEI-RQL scores for the domains clarity of vision, near vision, far vision, diurnal fluctuation, activity limitations, glare, symptoms, correction dependence, appearance, and satisfaction with correction (p < 0.001). Conclusion: Topography-guided photorefractive keratectomy improved vision-related quality of life in patients with a history of irregular astigmatism secondary to radial keratotomy.

Reproducibility of laser in situ keratomileusis flap thickness using a new multifunctional femtosecond laser platform and correlation with clinical preoperative measurements.

PURPOSE: To analyze the reproducibility of laser in situ keratomileusis (LASIK) flap thickness (target 120 µm) using the multifunctional femtosecond laser (Lensx) and correlate postsurgical measurements with preoperative factors. SETTING: Hospital Oftalmológico Visão Laser, Santos, São Paulo, Brazil. DESIGN: Prospective case series. METHODS: Patients with stable refraction for over a year were evaluated. Patients who submitted to refractive surgery with -1.25 to -6.00 diopters (D), with or without astigmatism up to -4.00 D, and corneal curvature of 40.00 to 47.00 D were included. At 100 days postoperatively, an independent examiner performed 4 high-resolution tomographic sections of the cornea for each eye at 45- to 225-degree, 90- to 270-degree, 135- to 315-degree, and 0- to 180-degree meridians. Two masked experienced observers analyzed each section using measuring points located at the center of the cornea (0.0 mm), 2.0 mm to the left and to the right of the center, and 4.0 mm to the left and to the right of the center. RESULTS: The study comprised 33 patients (63 eyes), aged 21 to 50 years. A significant difference from the target flap thickness (120 µm) was found in 2 of 20 measurements; however, the actual difference was approximately 2.2 µm. Interrater reliability was excellent (ICC > 0.75), with an interrater bias close to 0. Clinical measurements were not predictive of the set of 20 postoperative measurements. CONCLUSION: Reproducibility of the multifunctional femtosecond laser was good for LASIK flap creation and no predictive correlation was found with preoperative clinical factors.