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Aim The aim of the study was to report on the ocular response analyzer and posterior segment optical coherence tomography findings in refractive surgery candidates. Patients and methods The study was conducted on 100 eyes of 50 (37 females) patients seeking refractive surgery at a private eye center in Alexandria, Egypt. Following detailed history taking, all study participants were subjected to a thorough ophthalmic examination including assessment of uncorrected and best-corrected visual acuity, manifest and cycloplegic refraction, slit-lamp examination, measurement of intraocular pressure (IOP) using Goldmann applanation tonometry, and fundus examination using a high plus auxiliary lens. Optical coherence tomography and corneal biomechanical properties were then studied using the Reichert ocular response analyzer. Results The mean±SD age of the study patients was 25.27±4.9 years and of contact lens wear (24% of study patients) was 2.5±0.9 years. The mean±SD of the manifest refractive error was −5.6±5.2 D sphere and −1.6±1.2 D cylinder and of the best-corrected visual acuity was 0.9±0.2. The mean±SD of the IOPg, IOPcc, corneal hysteresis and cornea resistance factor were 14.9±3.8, 16.5±3.4, 9.3±1.9, and 9.4±2 mmHg, of the Peripapillary Retinal Nerve Fibre Layer (pRNFL) thickness were 68.9±20.5 μ nasal, 113.3±20.7 μ superior, 77.7±16 μ temporal, and 119.3±21.5 μ inferior and of the central macula thickness was 270.8±22.9 μ. Conclusions The corneal biomechanical properties and the macular nerve fiber layer thickness are not correlated with the refractive error of the eye, whereas the peripapillary nerve fiber layer thickness correlates with the refractive error and the visual acuity. Screening of the corneal biomechanical properties and the nerve fiber layers is recommended for refractive surgery candidates. [ABSTRACT FROM AUTHOR]

Background Intracorneal ring segment (ICRS) implantation in combination with corneal collagen cross-linking (CXL) has shown promising results in improving the visual acuity and reducing refractive errors, but long-term results are lacking. Aim To evaluate the long-term outcomes (>5 years) of simultaneous CXL and femtosecond laser-assisted intracorneal stromal ring segment implantation for management of keratoconus. Design This was a noncomparative, noncontrolled retrospective single-center study. Patients and methods The study included 50 eyes of 37 patients with keratoconus who underwent simultaneous CXL and ICRS implantation and were followed up for at least 5 years regarding visual acuity, refraction, and corneal imaging. Results Best-corrected visual acuity showed statistically significant improvement, with mean changed from 1.07±0.41 to 0.40±0.30 LogMAR. The results showed significant improvement also after 5 years. The spherical equivalent also was significantly improved from a mean of −4.61±4.37 D to a mean of −1.41±−1.49 D. Keratometric readings also showed improvement of both K1 and K2. The mean K1 improved from a mean of 49.6±6.76–47.78±6.17 D, and the mean K2 improved from 55.04±7.34 to 52.67±7.38. The results were stable, with no statistically significant change after 5 years. Conclusions Simultaneous CXL and femtosecond laser-assisted ICRS is effective and stable for both visual outcome and refraction in patients with keratoconus. [ABSTRACT FROM AUTHOR]

Background Accelerated photoactivated chromophore for keratitis–corneal collagen cross-linking (PACK-CXL) was investigated to be effective in the treatment of fungal keratitis in many studies. High-fluence CXL was used effectively in the treatment of progressive keratoconus but not tested in PACK-CXL for fungal infection. Aim To evaluate the antifungal efficacy of high-fluence CXL in the treatment of induced fusarium corneal ulcer in rabbits. Design This is an experimental interventional study. Patients and methods This is an experimental interventional study conducted on 16 eyes of eight rabbits for which fusarium corneal infection was induced by intrastromal corneal injection. The rabbits were divided into two groups: group A received no treatment and was left as a control group. Group B received a single high-fluence PACK-CXL session. All rabbits were followed up for 6 days and then the eyes were enucleated. Culture was performed for seven corneas and histopathology for the remaining cornea. Results There was statistically significant deterioration in group A (P=0.003), while a statistically significant clinical improvement was seen in group B (P<0.001). The median colony-forming units was more in group A (4×104) than in group B (2×102). Histopathological examination also revealed less inflammatory signs in high-fluence PACK-CXL-treated group. Conclusions High-fluence PACK-CXL total ultraviolet A fluence of 7.2 J/cm2 is effective in the treatment of mycotic keratitis. [ABSTRACT FROM AUTHOR]

Background New approaches have been created to raise the chances of achieving big bubble (BB) in deep anterior lamellar keratoplasty (DALK); however, the BB formation is still uncertain in all cases. Other factors likely contribute to the success of bubble formation. Aim To evaluate the effect of preoperative curvature of the cornea on the success of BB formation in DALK for keratoconus. Design A prospective, comparative, nonrandomized study. Patients and methods The study was performed on 50 keratoconus patients. We compared the data of 25 patients who had successful type-1 bubble formation versus another 25 patients in whom the bubble formation failed. Both groups were compared regarding the keratometric readings recorded from the preoperative pentacam. Results The analysis showed statistically significant lower K1, K2, and Km values in the group where BB has been successfully achieved. We also found that lower K1 value was the only significant studied factor after the multivariate analysis. Conclusion Keratoconus patients with preoperative flatter corneas have slightly higher chances for successful BB formation during DALK surgery. [ABSTRACT FROM AUTHOR]

Background The corneal cross-linking procedure has been proven to be an effective method to treat and stabilize keratoconus progression, but early vision rehabilitation is still needed in patients. Aim The aim was to compare the results of the combined CXL and intrastromal corneal ring segment implantation procedure to that of the cross-linking-alone procedure in terms of visual acuity, refraction, and some corneal topographic parameters in keratoconic patients. Design This was a prospective, comparative, and interventional study. Patients and methods This study was carried out on 44 keratoconic patients (60 eyes) of both sexes who ranged from 18 to 36 years. Thirty eyes were subjected to the CXL-alone procedure and 30 eyes were subjected to the combined procedure. Measurements were performed in all patients preoperatively and at 3, 6 months, and 1 year postoperatively including unaided visual acuity, best-corrected visual acuity, refractive, and topographic outcomes. Results Through the entire study period, both procedures were safe and effective in treating and stabilizing keratoconus progression. Furthermore, the combined group showed additional improvements over the CXL group for the following: UDVA at 3 months (P=0.0028), best-corrected visual acuity at 1 year (P=0.011), refractive and keratometric astigmatism at all follow-up visits and corneal asphericity at 3 months (P=0.013) and 6 months (P=0.0221) of follow-up. No severe intraoperative or postoperative complications were observed during the entire study period in either group. Conclusions The combined procedure is safe and effective for earlier improvement of visual and refractive outcomes in addition to the corneal stabilizing effect. [ABSTRACT FROM AUTHOR]