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Purpose: To assess the effect of preoperative Belin-Ambrósio deviation (BAD-D) index on 2-year visual, refractive, and tomographic outcomes, as well as the efficacy and safety of photorefractive keratectomy (PRK) surgery., Setting: Eye clinic, Mashhad, Iran., Design: Prospective cohort study., Methods: This study included 66 patients (66 eyes) who underwent PRK surgery, with a minimum follow-up period of 2 years. Participants were divided into 2 groups: preoperative BAD-D ≥1.60 (high BAD-D) and preoperative BAD-D <1.60 (low BAD-D). Preoperative and postoperative visual, refractive, and tomographic parameters were evaluated, and the efficacy and safety of the procedure were compared between groups., Results: 66 patients with a mean age of 35.50 ± 8.21 years (range 22 to 55 years) were included. Postoperatively, the mean spherical equivalent (SE) of refractive error was +0.32 ± 0.65 diopters (D) in the high BAD-D group and +0.18 ± 0.66 D in the low BAD-D group ( P = .40). In addition, at 2 years of follow-up, the mean uncorrected distance visual acuity was 0.98 ± 0.07 in the high BAD-D group and 0.97 ± 0.08 in the low BAD-D group ( P = .905). Among the postoperative tomographic parameters, front elevation thickness, maximum Ambrósio relational thickness, astigmatism, and central corneal thickness were significantly different between the 2 groups (all, P < .05). At the 2-year follow-up, the mean Safety Index was 1.02 ± 0.04, and 1.01 ± 0.04 in high and low BAD-D groups, respectively ( P = .37), and the mean Efficacy Index was 0.99 ± 0.07 and 0.98 ± 0.06 in high and low BAD-D groups, respectively ( P = .40)., Conclusions: The preoperative BAD-D index does not predict postoperative visual, refractive, and tomographic outcomes in patients with low-to-moderate myopia. However, in patients with normal preoperative BAD-D values, higher agreement was expected between the attempted and achieved SE., (Copyright © 2024 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

A 24-year-old man was referred for postrefractive surgery evaluation. The patient had a history of uneventful laser in situ keratomileusis (LASIK) in both eyes 3 months previously. According to the surgeon who originally performed the surgery, on slitlamp examination, only microstriae in the left eye was detected on postoperative day 1 and a more conservative follow-up approach was adopted without further immediate intervention. The patient returned only 3 months after surgery, complaining of low vision in the left eye that, according to the patient, had been present since postoperative week 2. The patient was then referred for examination and surgical procedure with a diagnosis of significant postoperative striae. The slitlamp examination revealed a LASIK flap with striae, epithelial filling, and a wrinkled appearance (Figure 1JOURNAL/jcrs/04.03/02158034-202312000-00017/figure1/v/2023-11-20T151558Z/r/image-tiff). There were no signs of infection or inflammation. Originally, the LASIK flap was programmed to be 110 μm. Preoperative manifest refraction in the right eye was -5.25 (20/20) and in the left eye was -5.25 (20/20). Assuming it is a case of late-approach LASIK flap striae, how would you proceed? Would you try to hydrate and lift the flap and just reposition it? Would you avoid lifting and associate phototherapeutic keratectomy (PTK) with excimer laser on top of the flap? Would you consider topo-guided surgery with regularization of the visual axis or even amputation of the flap?, (Copyright © 2023 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Purpose: The aim of this study was to evaluate and compare early corneal biomechanical changes after small-incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK)., Methods: The study comprised 74 patients eligible for refractive surgery, equally allocated to PRK (37 patients) and SMILE (37 patients). Corneal biomechanical properties were recorded and compared between the 2 groups at preoperatively and 3 months after surgery using a dynamic ultra-high-speed Scheimpflug camera equipped with a noncontact tonometer., Results: Both procedures significantly affected corneal biomechanical properties at 3 months after surgery. Patients in the PRK group showed significantly better results for deformation amplitude ratio (DA ratio) ( P = 0.03), maximum inverse radius (InvRadMax) ( P = 0.02), and A2 time ( P = 0.03). The mean changes in DA ratio, HC radius, InvRadMax, and Ambrosio relational thickness were significantly higher in the SMILE group in comparison with those of the PRK group (all, P < 0.05). In both groups, change in CCT was significantly correlated with changes in DA ratio and InvRadMax ( P < 0.05)., Conclusionss: Both SMILE and PRK refractive surgeries significantly altered corneal biomechanical properties but the changes were more prominent after SMILE., Competing Interests: The authors report no conflicts of interest. We warrant that this paper is original and has not been published in another journal., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To compare the efficiency and safety of two bandage contact lenses after photorefractive keratectomy (PRK)., Methods: In this double-blind study, 45 patients (90 eyes) received PRK in both eyes and wore bandage contact lenses (BCLs), PureVision (Bausch & Lomb, Rochester, NY, USA) in one eye and PureVision2 (Bausch & Lomb, Rochester, NY, USA) in the other eye, randomly assigned. The medication regimen after surgery was the same for both eyes. The epithelial defect's size, conjunctival hyperemia and lens centration were graded objectively using slit-lamp biomicroscopy on days 1, 3 and 5 after surgery. Also ocular symptoms of discomfort including tearing, photophobia, foreign body sensation and visual fluctuations were assessed subjectively at each visit., Results: The mean epithelial defect size on the first day after operation was similar in eyes fitted with PureVision (30.08 ± 5.30 mm²) and PureVision2 (30.25 ± 5.72 mm 2 ) lenses. (p = 0.79) Contact lens deposits and bulbar hyperaemia on days 1 and 3 after PRK were similar between the two eyes, but were significantly greater on day 5 for PureVision2 lenses. (p = 0.02; p = 0.04 respectively) There was no difference in contact lens decentration, and discomfort symptoms including pain, tearing, foreign body sensation, photophobia and visual fluctuations between the eyes fitted with PureVision and PureVision2. (p > 0.05) CONCLUSIONS: PureVision and PureVision2 contact lenses are equivalent as bandage lenses in important aspects such as corneal re-epithelialization and subjective comfort., although PureVision2 led to a higher incidence of contact lens deposits and conjunctival hyperemia early post-PRK., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To compare differences in the endothelial cells before and after photorefractive keratectomy (PRK) for myopia with refractive error graded mitomycin C (MMC) application., Methods: In a prospective randomized clinical trial, forty-eight myopic patients referred to Khatam-al-Anbia Eye Hospital, Mashhad, Iran, for PRK. Patients were treated with PRK by a Bausch and Lomb Technolas 217z excimer laser (Bausch and Lomb, Rochester, NY). MMC was applied after PRK 5 s for each diopter of spherical equivalent myopic refractive error corrected. The manifest refraction, visual acuity, MMC treatment length, corneal pachymetry and specular microscopy were evaluated preoperatively and at 1 and 6 months postoperatively., Results: A total of 48 cases (96 eyes, 68.75% female) were treated, with a mean age of 26.70 ± 4.89 years (range, 18-34 years). Postoperative cell density, cell size and polymegathism did not significantly change. On the other hand, standard deviation (SD) of cell size (P = 0.008), pleomorphism (P = 0.003) and coefficient of variation (CV) (P = 0.016) were significantly increased. None of these parameters was related to the length of MMC application. Corneal thickness decreased significantly after the operation but it increased 6 months postoperatively compared with the first month (P < 0.001)., Conclusion: MMC application for PRK in myopia can affect the endothelial cells, but in early follow-ups, it does not affect the cell density or size. Cell size was changed but it was obvious not in mean cell size, but in SD and CV. MMC time below the 30 s was not significant on endothelial cell changes.

Purpose: To evaluate and compare early postoperative pain after photorefractive keratectomy (PRK) and corneal crosslinking (CXL)., Setting: Khatam-al-Anbia Eye Hospital, Mashhad, Iran., Design: Prospective case series., Methods: The PRK group included patients with simple refractive errors whereas the CXL group included patients with clinical keratoconus. The groups were compared regarding the level of pain based on the visual analogue scale (VAS), verbal rating scale (VRS), and Wong-Baker FACES pain rating scale immediately after surgery, 6 hours postoperatively, and 1, 3, and 7 days postoperatively. The epithelial defect size was measured at 6 hours after surgery and 1 day and 3 days after surgery in both groups., Results: The study comprised 68 patients (34 patients in the PRK group and 34 patients in the CXL group). The epithelial defect size was significantly smaller in the CXL group than in the PRK group (P < .001); however, the amount of pain was significantly higher after CXL than after PRK based on VAS and VRS (P = .04 and P = .019, respectively). In the FACES scaling system, the pain score was also higher in the CXL group than in the PRK group. However, the difference was not statistically significant. No intraoperative or postoperative complications were observed during follow-up., Conclusions: The epithelial defect healing rate was statistically significantly faster in the CXL group than in the PRK group. However, the level of pain was greater in the CXL group, suggesting that postsurgical pain might be influenced by other factors than the epithelial defect., (Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the refractive, visual, and aberrometric outcomes between wavefront-guided photorefractive keratectomy (PRK) and aspheric PRK in myopic patients., Setting: Khatam-al-Anbia Eye Hospital, Mashhad, Iran., Design: Prospective randomized clinical trial., Methods: One eye of each patient was randomly assigned to excimer laser wavefront-guided PRK (Zyoptix) and the other eye to excimer laser aspheric PRK (Technolas 217z). The preoperative and 3-month and 6-month postoperative refractive errors, visual acuity, contrast sensitivity, and higher-order aberrations (HOAs) were compared between the groups., Results: Ninety-six eyes (48 patients) were enrolled. At the last postoperative visit, there were no between-group differences in uncorrected distance visual acuity (UDVA) (P = .987) or corrected distance visual acuity (P = .416). The mean spherical equivalent was -0.076 diopter (D) ± 0.029 (SD) in the wavefront-guided group and -0.077 ± 0.075 D in the aspheric PRK group (P = .684). Postoperatively, the mean area under the log of contrast sensitivity function (AULCSF) with and without glare testing improved over preoperative values (both P < .001). There was no statistically significant between-group difference in the AULCSF with glare (P = .903) or without glare (P = .978). Total HOAs increased after PRK in both groups, although aspheric PRK induced fewer HOAs than wavefront-guided PRK (P = .04)., Conclusions: Both PRK methods equally improved postoperative UDVA and contrast sensitivity. The HOAs increased after treatment with both methods; however, aspheric ablation induced statistically fewer HOAs than wavefront-guided ablation., Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned., (Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

The goal of this study was to compare differences in the mean angle kappa and its intercepts before and after photorefractive keratectomy (PRK) for myopia. In a prospective controlled study, myopic patients were treated with aspheric wavefront-guided (personalized) PRK with a Bausch & Lomb Technolas 217z excimer laser. The manifest refraction, visual acuity, and angle kappa were evaluated preoperatively and at 1 and 6 months postoperatively. The same operator performed all angle kappa measurements using Orbscan IIz. A total of 48 cases (96 eyes, 68.75 % female) with a mean age of 26.70 ± 4.89 years (18-34 years) were treated. The preoperative and postoperative mean angle kappa values were not significantly different (4.97 ± 1.24 vs 4.99 ± 1.10 at 6 months). The average horizontal distance (x-intercept) between the visual axis and pupillary axis intersection on the corneal surface measured before surgery (-0.562 ± 0.074 mm) did not significantly differ from the values measured at 1 and 6 months after surgery (-0.559 ± 0.048 and -0.554 ± 0.055 mm, respectively). Similarly, the average vertical distance (y-intercept) values did not differ before and at 1 and 6 months after surgery (0.156 ± 0.225, 0.142 ± 0.040, and 0.149 ± 0.33 mm, respectively). No differences in the angle kappa or its corneal intercepts were observed between pre- and post-PRK. This finding implies that PRK does not change the corneal vertex locations.

Nocardia keratitis occurred in 4 eyes of 3 patients (2 women and 1 man) who had photorefractive keratectomy (PRK) by the same surgeon at the same center. Two eyes of the first 2 patients required lamellar keratectomy to debulk the involved stroma and obtain specimens for microbiological and histopathological evaluation. Light microscopic examination disclosed gram-positive and acid-fast filaments of Nocardia that were confirmed by the microbiological results. Diagnosis of Nocardia keratitis in the third case was not as challenging as in the first 2 cases because of a high index of suspicion. Confocal scans of all cases disclosed hyperreflective and slender, fibril-like structures in the corneal stroma. All eyes responded favorably to topical amikacin and the infection resolved without recurrence. The most probable cause of the outbreak was inadequate attention to sterility during surgery.