Formaldehyde is frequently used in occupational environments (Folia Morphol 2016; 75, 4: 518-526)

PurposeTo determine the incidence of interface fluid syndrome (IFS) secondary to steroid-induced elevation of intraocular pressure (IOP) following laser in situ keratomileusis (LASIK) in myopic Egyptian patients.MethodsThis retrospective case series study was conducted at El-Gowhara Private Eye Center. The medical records of 1,807 patients (3,489 eyes), who underwent LASIK to correct myopia from April 2012 to December 2015 were included. The patients were operated on and reviewed by one surgeon (AAG) for IFS after LASIK associated with elevation of IOP (as compared to preoperative values).ResultsThis paper reports the incidence of 2.9% (54 patients) (102 eyes) of IFS induced by increased IOP after LASIK in Egyptian patients. The medical records of 1,807 patients (3,489 eyes) with mean age ± standard deviation (SD) 26.4±2.7 years, who presented with mean myopia ± SD −4.50±1.3 D, mean astigmatism ± SD −1.43±0.8, mean IOP ± SD 15.2±1.2 mmHg, and mean central corneal thickness ± SD 549±25.6 μm, were included. The preoperative anterior and posterior segments, corneal topography, and Schirmer’s test were unremarkable.ConclusionLimiting topical steroids and routinely measuring the IOP post-LASIK are necessary steps to prevent IFS, especially in case of myopia. A high index of suspicion is required to make a diagnosis. High-resolution optical coherence tomography is helpful to confirm the diagnosis.

PurposeTo evaluate refractive outcomes of two management approaches after suction loss during the small-incision lenticule extraction (SMILE) technique.Patients and methodsThis retrospective and comparative study was conducted at the El-Gowhara Private Eye Center. It included 26 consecutive eyes of patients who experienced suction loss during the SMILE technique. Patients were divided into two groups by the technical difficulties in redocking: in group A (12 eyes) suction loss occurred after the posterior lenticular cut and the creation of side-cuts, then suction was reapplied, and the procedure was completed; in group B (14 eyes) suction loss occurred after the posterior lenticular cut and the creation of side-cuts, then the procedure was postponed for 24 hours and completed with the same parameters. Manifest refraction outcomes were measured and compared 6 months postoperatively.ResultsThis study included 26 eyes with suction loss during the SMILE technique: five patients with suction loss in both eyes, nine patients with suction loss in the right eye and seven patients with suction loss in the left eye. The incidence of suction loss in this study was 2.7%. At the postoperative 6-month follow-up time, there were statistically significant differences in refraction outcomes between the two groups, with a hyperopic shift in group A compared with group B.ConclusionA good refraction outcome can be achieved with appropriate management of suction loss during the SMILE technique, and it is recommended to postpone the treatment if this happens.

Background The study aimed to assess the role of intraoperative mitomycin-C (MMC) application during hyperopic LASIK correction (+ 1.00 D to + 6.00 D) by examining topographic corneal changes and incidence of regression over a one-year follow-up period. Methods This comparative randomized control study included 68 hyperopic patients (136 eyes) divided into two groups; Group A included 34 patients (68 eyes) that had LASIK with the application of 0.02% MMC for 10 s on the stromal bed after excimer laser treatment, and group B included 34 patients (68 eyes) that had LASIK without MMC application. Uncorrected distance visual acuity (UDVA), refraction, keratometry and topography were recorded at 1st week and 1st, 3rd, 6th, and 12th months postoperation. Predictability and treatment efficacy were also recorded at the end of the follow-up period. Results Better predictability was noted in group A than in group B at the 6 month and 12 month follow-up visits, with a mean cycloplegic refraction SE of + 0.5 ± 0.31 D in group A and + 0.67 ± 0.39 D in group B at the 6 month visit, and + 0.63 ± 0.37 D in group A and + 0.89 ± 0.48 D in group B at the 12 month visit. The efficacy of the treatment at the end of the follow up period was better in group A than in group B. Group A showed fewer topographic corneal changes than group B. Conclusions Intraoperative MMC application during hyperopic LASIK achieves better predictability and efficacy and induces fewer topographic changes and lower regression rate of hyperopia during the first postoperative year. Trial registration the Pan African Clinical Trial Registry PACTR201901543722087 , on 29 January 2019.

Background To evaluate predictability, stability, efficacy, and safety of transepithelial photorefractive keratectomy (TPRK) using smart pulse technology (SPT) (SmartSurface procedure) of Schwind Amaris with mitomycin C for correction of post small incision lenticule extraction (SMILE) myopic residual refractive errors. Method This study is a prospective, non-comparative case series conducted at a private eye centre in Ismailia, Egypt, on eyes with post-SMILE myopic residual refractive errors because of undercorrection or suction loss (suction loss occurred after the posterior lenticular cut and the creation of side-cuts; redocking was attempted, and the treatment was completed in the same session with the same parameters) with myopia or myopic astigmatism. The patients were followed up post-SMILE for six months before the SmartSurface procedure, and then they were followed up for one year after that. TPRK were performed using Amaris excimer laser at 500 kHz. The main outcomes included refractive predictability, stability, efficacy, safety and any reported complications. Results This study included 68 eyes of 40 patients out of 1920 total eyes (3.5%) with post-SMILE technique myopic residual refractive errors. The average duration between the SMILE surgery and TPRK was 6.7 ± 0.4 months (range 6 to 8 months). The mean refractive spherical equivalent (SE) was within ± 0.50 D of plano correction in 100% of the eyes at 12 months post-TPRK. Astigmatism of < 0.50 D was achieved in 100% of the eyes. The mean of the residual SE error showed statistically significant improvement from preoperative − 1.42 ± 0.52 D to 0.23 ± 0.10 D (P < 0.0001). Uncorrected distance visual acuity (UDVA) (measured by Snellen's chart and averaged in logMAR units) was improved significantly to 0.1 ± 0.07 (P < 0.0001). UDVA was 0.2 logMAR or better in 100% of the eyes, 0.1 logMAR or better in 91.2% of the eyes, and 0.0 logMAR in 20.6% of the eyes. Corrected distance visual acuity (CDVA) remained unchanged in 79.4% of eyes. 14.7% of eyes gained one line of CDVA (Snellen). 5.9% of eyes gained two lines of CDVA (Snellen). Conclusion Transepithelial photorefractive keratectomy using smart pulse technology with mitomycin C enhancement after SMILE is a safe, predictable, stable, and effective technique.

Purpose To assess the relationship between the axial length and post-LASIK regression in myopic patients. Methods This is a retrospective case series study conducted at a private eye centre, Ismailia, Egypt. The clinical records of the patients, who experienced LASIK to correct myopia from January 2016 to January 2018, were analysed for myopic regression. The patients were operated on, examined, and followed-up 1 year by one surgeon (AAG). Results This study included 1219 patients (2316 eyes) with myopia. Mean ± SD of pre-operative spherical equivalent (SE) was − 4.3 ± 2.1D, range (− 0.50 to − 10.0D). Mean ± SD age of the patients was 26.4 ± 6.8 years, range (21 to 50 years). Male to female ratio was 30.5 to 69.5%. The cumulative incidence rate of myopic regression according to the medical records of the patients was 25.12% (582 eyes out of total 2316 eyes) along the 2 years of this study (12.6% per year). Of the total patients, 14.94% had pre-operative high myopia, 35.84% had pre-operative moderate myopia, and 49.2% had pre-operative low myopia. Of the patients with myopic regression, 52.6% had pre-operative high myopia, 34% had pre-operative moderate myopia, and 13.4% had pre-operative low myopia. The mean ± SD of the axial length of the patients with myopic regression was 26.6 ± 0.44 mm, range (26.0 to 27.86 mm), while the mean ± SD of the axial length of other patients with stable refraction was 24.38 ± 0.73 mm, range (22.9 to 25.9 mm) (t test statistic = 69.3; P value < 0.001). Conclusions Pre-operative high axial length increases the risk of myopic regression after LASIK.

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Aim To evaluate the contributions of anterior corneal and ocular residual astigmatism to autorefraction astigmatism in adult myopic and myopic astigmatic subjects and how these compensate each other. Subjects and Methods This retrospective study was completed in private eye centre, Ismailia, Egypt, between September 2017 and November 2019. The study included eyes with myopia (0.5 to 10.0D) or myopic astigmatism (0 to 8.5D). The refractive errors, including autorefraction astigmatism, were measured after using 1% cyclopentolate with autorefractometer (Topcon, Tokyo Optical Co., Ltd., Japan). Corneal topography (Sirius; CSO, Florence, Italy) was used to measure anterior corneal astigmatism. Ocular residual astigmatism was measured by vectorial subtraction of the anterior corneal astigmatism from autorefraction astigmatism determined to the corneal plane. Results This study included 1158 eyes (right 582 and left 576) with myopia or myopic astigmatism of 582 participants (206 males with 406 eyes and 376 females with 752 eyes). The mean±SD age of the total participants was 26±5.7 years, range (21 to 50 years). The mean±SD of spherical error was −3.2±1.9D, range (−0.5 to −10.0D). The mean±SD of autorefraction astigmatism was 1.13±1.1D; range (0.5 to 8.5D). The mean±SD of anterior corneal astigmatism was 1.22±0.8D; range (0.03 to 5.6D). The mean±SD of ocular residual astigmatism was 0.6±0.5D; range (0 to 4.8D). Of the total eyes, 75.4% had significant autorefraction astigmatism, 82.5% had significant anterior corneal astigmatism, and 16.8% had significant ocular residual astigmatism. Conclusion The percentage of the significant autorefraction astigmatism (>0.5D) was 75.4% which is mainly anterior corneal. In 26.8% of participants, anterior corneal astigmatism is compensated by ocular residual astigmatism.