PURPOSE:To report the causes of childhood-onset uveitis in a tertiary pediatric ophthalmology hospital in Egypt.METHODS:Retrospective study of the medical records of all uveitis patients following up at a tertiary pediatric ophthalmology hospital in Egypt from January 2017 to December 2020.RESULTS:The present study included 388 patients. The most common anatomical category was intermediate uveitis (30.4%), and around half of these children had pars planitis. This was followed by panuveitis (25.5%), posterior uveitis (23.5%), and anterior uveitis (20.6%), in decreasing frequency. Juvenile idiopathic arthritis, toxoplasmosis, and Vogt-Koyanagi-Harada syndrome were the most common causes of anterior uveitis, posterior uveitis, and panuveitis respectively. Cataract (40.5%), glaucoma (33.8%), and cystoid macular edema (31.6%) were the most frequent ocular complications.CONCLUSION:The present report provides the relative prevalence of the different anatomical types of uveitis, as well as their main causes in a cohort of Egyptian patients with childhood-onset uveitis.

Purpose:To compare between two accelerated corneal cross-linking (A-CXL) protocols in the management of keratoconus (KC) as regard to the extent of corneal treatment.Methods:This retrospective, comparative study included patients having mild to moderate, progressive KC. The study population was divided into two groups; group 1 enrolled 103 eyes of 62 patients who received pulsed light A-CXL (pl-CXL) at a power of 30 mW/cm2 with an irradiation time of 4 minutes, while group 2 comprised 87 eyes of 51 patients who received continuous light A-CXL (cl-CXL) at a power of 12 mW/cm2 with an irradiation time of 10 minutes. Recordings of the central and peripheral demarcation line depths (DD), and the maximum (DDmax) and minimum (DDmin) DD, using anterior segment optical coherence tomography, were compared between the two studied groups one month after the treatment protocol. Treatment stability was also evaluated pre and postoperatively (one year following surgery) by comparing the refractive and keratometric outcomes in both groups.Results:The differences between the preoperative corneal thickness (minimum and central) and the epithelial thickness measurements between both groups were not statistically significant. Although group 1 had slightly larger central DD (223.4 ± 62.3 um), DDmax (240.4 ± 61.8 um), and DDmin (201 ± 54 um) than those of group 2 (221.8 ± 37 um, 229.1 ± 38.4 um, and 212 ± 37.2 um, respectively), the differences between both groups' measurements were not statistically significant. Also, the two groups showed statistically insignificant differences regarding the subjective refraction and the average and maximum keratometry pre and postoperatively, denoting visual, refractive, and keratometric stability in both groups.Conclusion:Longer duration cl-CXL seems to be as effective as pl-CXL regarding both postoperative stability and the extent of corneal tissue penetration by the ultraviolet treatment.

Introduction: This study aimed to discover and document the potential of visual and ocular sequelae of computer vision syndrome (CVS) among medical students. Methods: This cross-sectional case-control study was conducted on medical students (n=4030) of five universities in Egypt. All students completed a specially designed and validated CVS questionnaire survey (CVS-F3). Students with ≥5 CVS symptoms constituted a risk group (n=352), while students with 1-4 CVS symptoms constituted a low-symptoms group (n=3067). Students from the control and risk groups were examined using objective methods, such as visual acuity, subjective refraction, dry eye disease tests, and anterior segment and fundus examinations. Students who complained of visual blur underwent multifocal electroretinography mfERG examinations (mfERG group). Results: The CVS-F3 indicated that 84.8% of students had complaints that might be related to CVS, however, our ophthalmic examination group revealed only a 56% CVS prevalence rate. The most common single screen type used by 70.4% of students was the smartphone, and the most common complaint was headache (50.2%). Multivariate logistic regression analysis revealed that CVS was significantly associated with increased screen-hours, including >2 screen-hours daily (odds ratio [OR], 2.48; P<0.0001), >2 screen-hours at night (OR, 1.79; P=0.003), and ≥3 screen-years (OR, 1.69; P=0.006). In the mfERG group, 37% demonstrated reduced amplitudes of mfERG rings and quadrants, indicating reduced foveal responses. Conclusion: CVS-questionnaires overestimate the true CVS prevalence and sequelae, which could be accurately detected by objective ophthalmic examination. Smartphones primarily caused CVS among students, with CVS severity increasing in correlation with shorter eye-to-screen distance and frequent use. Contact lens wearing doubled the risk of CVS development and augmented its severity. CVS might affect macular integrity with screen-induced foveal dysfunction. Clinical Trials Registration: PACTR201811618954630.

Purpose To assess the visual, ocular, extraocular, and multifocal electroretinography (mfERG) outcomes of computer vision syndrome (CVS) among medical students. Methods This study was designed as a cross-sectional case-control study that included 733 medical students. All students completed a specially designed and validated CVS questionnaire survey (CVS-F3). Students from the control (No-CVS) and CVS groups underwent comprehensive ophthalmic examinations including the mfERG examinations. Our main outcome measures included uncorrected and corrected distance visual acuity (UDVA and CDVA, resp.) measurements, subjective and cycloplegic refractions, slit-lamp examination, intraocular pressure measurement, pupillary reflexes tests, ocular movements' tests, dry eye disease tests, and fundus and mfERG examinations. Results The CVS-F3 identified that 87.9% of students had complaints that might be related to CVS. We documented a 76% prevalence rate in students undergoing an ophthalmologic exam. The most common ocular and extraocular complaints included visual blur and headache (40.9% and 46.8%, resp.). Statistical logistic and linear regression analyses showed that refractive errors, prolonged screen-hours, close eye-screen distance, improper gaze angle, poor screen-resolution, and screen-glare were risk factors for developing CVS and influencing its severity. In the mfERG subgroup, 42.5% demonstrated reduced amplitudes of mfERG rings and quadrants, indicating reduced foveal responses. Conclusion Surveys cannot yield an accurate CVS prevalence. However, they help to identify subjects at risk who should be comprehensively assessed to confirm or exclude CVS diagnosis. Smartphone misuse primarily caused CVS among users. Our mfERG findings might be a sign of potential CVS visual sequelae; however, future studies are warranted. Clinicians need to understand these sequelae to appropriately identify and treat CVS.

Abstract Aim of the Work To compare visual acuity, refractive and topographic outcome between small incision lenticule extraction (SMILE) and wavefront-guided femtosecond laser-assisted in situ keratomileusis (WFG FS-LASIK) in patients with myopic astigmatism. Patients and methods This prospective, non-randomized, comparative clinical study included 60 eyes of 30 patients with simple or compound myopic astigmatism presenting for refractive error correction. Femtosecond assisted LASIK group included 30 eyes and SMILE group included 30 eyes. The following tests were done for all patients preoperatively and at 3 months postoperatively: full ophthalmological examination, manifest refraction, UDVA, CDVA, corneal topography using combined schimflug and placcido disc imaging namely Pentacam. (Oculus Inc.) and wavefront analysis using ATLAS 9000 (Carl Zeiss Meditec) Main Outcome Measures: Uncorrected distance visual acuity (UDVA), corrected disctance visual acuity (CDVA), manifest refraction, Efficacy, safety, predictability, corneal higher order aberrations. Results At 3 months, the mean manifest refractive spherical equivalent (MRSE) in SMILE group was -0.33 ± 0.34 D and the mean MRSE in FS- LASIK group was 0.23 ± 0.35 D and there was a statistically significant difference between both groups (P < 0.05). mean postoperative cylinder was -0.56 ± 0.28 D in SMILE group and -0.53 ± 0.38D in FS-LASIK with statistically significant difference ( P = 0.254 ) 93% and 93% of eyes in the SMILE and FS-LASIK groups were within ± 0.5 D; 96.67% and 100% of eyes in the SMILE and FS-LASIK groups, respectively, were within ± 1 D. There were 86.66% of treated eyes in the SMILE group, and 93.33% treated eyes in the FS-LASIK group that had 20/25 or better UDVA. Regarding safety, the CDVA in the SMILE group, 20 eyes (66.67%) showed no change, 8 eyes (27%) gained 1 line, 2 eyes (7%) lost 1 line, and no eyes lost more than 1 line. whereas in the FS-LASIK group, 27 eyes (90%) exhibited no change, 2 eyes (6.66%) gained 1 line, 1 eye (3.33%) lost 1 line, and no eyes lost more than 1 line and There was no statistically significant difference between both groups (P = 0. 554 ). Regarding corneal asphericity, both procedures increased Q-value with no statistically significant difference between both groups (P = 0. 052). Regarding corneal higher order aberrations, both procedures significantly increased total corneal aberrations but there was no statistically significant difference in the change in RMS of total corneal higher order aberration (P = 0.434) .but SMILE increased RMS of coma aberration significantly more than FS-LASIK (P = 0. 029). Conclusion both SMILE and FS-LASIK procedures have shown excellent efficacy, safety, and predictability for the correction of myopia and myopic astigmatism. SMILE was closer to emmetropia regarding sphere and spherical equivalent, However, astigmatic undercorrection was noted after both surgeries with increased astigmatism. Both procedures increased the total corneal higher order aberrations with no statistically significant difference between both groups. A higher vertical coma was found in SMILE than WFG FS-LASIK.

The objective of this study is to compare the endothelial safety of femtosecond laser (FSL) energy at two different dissection depths in FSL-assisted deep anterior lamellar keratoplasty (FSDALK) for keratoconus. This prospective double-armed interventional study included 25 eyes from 21 patients with advanced keratoconus who underwent FSDALK (big bubble technique) at a trephination depth of 110 µm in group I (11 eyes) and 80 µm in group II (14 eyes)—all of which were anterior to the Descemet’s membrane (DM). Visual acuity measurement, anterior and posterior segment examination, corneal tomography, and specular microscopy were performed preoperatively and at 3, 6, and 12 months, postoperatively. Endothelial cell density, coefficient of variation, percentage of cell hexagonality, and pachymetry were used to evaluate endothelial safety. No statistically significant difference in any of the endothelial safety parameters was found between the two groups. The mean 12-month postoperative endothelial cell loss rate was 17.46% and 12.91% in group I and II, respectively (P = 0.345). Most of the endothelial cell loss occurred during the first 3 months after surgery. Group II showed statistically greater improvement in the mean keratometry values at all follow-up visits. The endothelial safety profiles of lamellar FSL cuts at 110 µm and 80 µm anterior to the DM are comparable. Cuts as deep as 80 µm anterior to the DM can be safely applied without causing significant injury to the endothelium. Further studies are needed to compare the endothelial safety profiles of different FSL platforms available in the market. Trial registration PACTR201901615323963. Registered 24 November 2018—retrospectively registered.

PURPOSE:To compare the efficacy of implanting a single Keraring segment according to a novel Q-value-based nomogram (QN) to that of segment implantation according to the manufacturer's standard nomogram (SN), for keratoconus treatment.METHODS:This was a prospective, randomized controlled trial of 104 patients (104 eyes) with Amsler-Krumeich grade 1 or 2 keratoconus, and type 1 or 2 cone asymmetry determined according to manufacturer's classification. They were randomly distributed into two groups: group A patients (n = 52) underwent Keraring implantation according to the SN, and group B patients (n = 52) underwent implantation of a single (210° arc-length) Keraring segment according to the QN. Both treatments were combined with accelerated transepithelial cross-linking, and follow-up was 6 months. Main outcome measures were preoperative and postoperative visual acuity, subjective refraction and corneal topography.RESULTS:At postoperative month 6, group B exhibited statistically significantly higher values of mean uncorrected distance visual acuity (UDVA), sphere, K2, K-average, K-max and Q-anterior (p = 0.02, 0.01, 0.002, 0.001, 0.0001 and 0.03, respectively) compared to that of group A. However, group A exhibited better refractive cylindrical improvements (p = 0.04). In group A, we documented spontaneous extrusion of one Keraring segment.CONCLUSION:Single 210° arc-length segment implantation using our objective QN was more efficacious for keratoconus treatment than using the subjective SN. The nomograms were comparable when the Q-anterior value was >-1.00; however, the QN was superior to the SN when the Q-anterior value was ≤-1.00. The QN yielded greater postoperative UDVA and smoother corneal remodelling than did the SN for treatment of grade 1 and 2 keratoconic eyes.

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Context The use of small incision lenticule extraction (SMILE) for compound myopic astigmatism has been subject to experimentation in the recent years. Furthermore, examination of corneal alterations has revealed conflicting conclusions, which could be attributable to demographic variation. Aims The aim of this study was to measure visual and keratometric efficacy of SMILE and correlate spherical equivalent (SE) decrements to keratometric alterations. Settings and design This was a prospective nonrandomized study. Thirty eyes of 15 patients were included in the study. Preoperative assessment included oculus Pentacam analysis. Patients were followed-up for up to 3 months, after which tomography was repeated. Statistical analysis used Descriptive statistics, t test, and linear regression analysis were carried out. Results There was a statistically significant improvement in postoperative uncorrected distance visual acuity and SE and a statistically significant change in Q value (P<0.001). The mean residual SE postoperatively was −0.14 D. A highly statistically significant negative correlation existed between SE difference and mean K difference with r=−0.980 and P value less than 0.001, and a highly statistically significant positive correlation existed between SE difference and Q value difference, with r=0.787 and P value less than 0.001. Conclusion SMILE is a safe and effective technique to correct cases with myopic astigmatism with an SE of up to −10 D, and a predictable positive correlation could be established between decrements in SE and decrements in anterior corneal steepening.

PURPOSE:To compare the safety and efficacy of standard 30 min epithelium-off cross-linking (CXL) versus photorefractive keratectomy (PRK) combined with accelerated epithelium-off cross-linking (AXL) for the treatment of progressive keratoconus (CXL-Plus).METHODS:This study was a prospective multicentre comparative clinical study. A total of 125 eyes of 75 patients with grade 1 keratoconus and documented progression were divided into two groups. Group A included 58 eyes treated with standard CXL. Group B included 67 eyes treated with combined PRK and AXL. The recorded data included UDVA, CDVA, subjective and objective refraction, keratometry and pachymetry using corneal topographies preoperatively and postoperatively at 3, 6, 12 and 24 months of follow-up.RESULTS:In group A, at 24 months of UDVA and CDVA were improved from 1.12 ± 0.38 and 0.58 ± 0.42 to 0.66 ± 0.20 and 0.20 ± 0.12 (LogMAR±SD). The spherical equivalent was reduced from 4.03 ± 1.18 to 1.78 ± 1.04 D. The cylinder reduction was 0.32 ± 0.19 D. In group B, at 24 months of UDVA and CDVA were improved from 1.26 ± 0.52 and 0.68 ± 0.36 to 0.58 ± 0.28 and 0.20 ± 0.16 (LogMAR ± SD). The spherical equivalent was reduced from 4.23 ± 0.95 to 1.92 ± 0.74 D. The cylinder reduction was ±1.76 D.CONCLUSION:Surprisingly, standard CXL showed close results to CXL-Plus at the 24th follow-up month. Standard CXL acted as a stabilizing procedure associated with a late myopic component reduction. CXL-Plus acted as a refractive and stabilizing procedure with an early effect on both the myopic and the astigmatic component but no later improvements. Standard CXL seems to be more powerful than AXL in its long-term effect. Therefore, in the future, we want to test the combination of PRK with standard CXL.

Aim The aim was to compare visual and central macular thickness (CMT) improvement and complications of adjunct intravitreal aflibercept (IAI) (2 mg) 0.05 ml followed by argon laser photocoagulation with adjunct intravitreal triamcinolone 4 mg/0.1 ml followed by argon laser photocoagulation in treating diabetic macular edema. Patients and methods A total of 30 eyes of 26 patients with type II diabetes having visual loss owing to clinically significant macular oedema (CSME) and confirmed by fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) were included. Patients were randomly assigned into two groups: group 1 was treated by IAI (0.05 ml) 2 mg/4 weeks (2q4) for a total of five doses, and group 2 by intravitreal triamcinolone acetonide 4 mg/0.1 ml. Best corrected visual acuity (BCVA) and clinical examination were done monthly. OCT was done at 2, 4, and 5 months. At 5 months, and CMT allowing, FFA was done and laser photocoagulation was performed on distinct leakers. OCT and FFA were done at 6 months, and results were compared between the two groups. Results At 6 months, there was a statistically significant improvement (P<0.05) of CMT in the IAI group compared with IVTA group (P=0.04 and 0.469, respectively). The IVTA group showed an ill-sustained effect, where four cases required reinjection. BCVA for the IAI group continued to improve throughout the study period, with statistically significant values until the end point (P=0.033). IVTA group showed statistically significant improvement in BCVA at the 2-month and 4-month visits, but insignificant changes thereafter (P=0.76 at 6 months). These changes were similar to CMT. Overall, five (33%) eyes in the IVTA group had an increase in intraocular pressure (IOP), with the highest at 12th week, and were treated by topical timolol 0.5% bid. Moreover, one patient had a visually significant posterior subcapsular cataract, and phacoemulsification with intraocular lens (IOL) implantation was performed after the study. One case in each group developed self-limited vitreous hemorrhage, which resolved spontaneously. Conclusion IAI/laser provides superior and more sustained anatomical CMT and BCVA results with fewer complications compared with the intravitreal triamcinolone/laser.

Purpose: To evaluate the effectiveness and safety of combined epithelium-off cross-linking (CXL) with photorefractive keratectomy (CXL Plus) for correction of the myopic and astigmatic components of keratoconus. Methods: Seventy-nine eyes of 46 patients who underwent CXL Plus were enrolled in this retrospective, multicenter, noncomparative clinical study. Uncorrected distance visual acuity, corrected distance visual acuity, refraction, keratometry, and pachymetry measurements were recorded preoperatively and at 3, 6, 12, and 18 months during follow-up. Results: The mean (±SD) preoperative uncorrected distance visual acuity and corrected distance visual acuity were 1.00 ± 0.22 logarithm of the minimum angle of resolution (logMAR) and 0.62 ± 0.38 logMAR, respectively, and improved to 0.71 ± 0.36 logMAR and 0.32 ± 0.18 logMAR postoperatively. The mean k value, mean corneal thickness at the thinnest location, and mean myopic and astigmatic components decreased from 46.58 ± 0.97 D, 473 ± 29 μm, 3.65 ± 1.72 D, and 1.83 ± 0.69 D preoperatively to 43.79 ± 1.17 D, 431 ± 38 μm, 1.02 ± 0.78 D, and 1.15 ± 0.26 D, respectively, during follow-up. Eleven eyes had delayed epithelial healing, 2 had stromal opacities, 1 had primary herpes simplex keratitis, and 5 showed progression of keratoconus. Conclusions: CXL Plus improved the refractive status of keratoconus during 18 months of follow-up, despite its potential early postoperative complications of delayed epithelial healing and corneal haze. CXL Plus reduced the myopic component more than the astigmatic component of keratoconus. However, the safety and stability of the procedure were offset by longer-term postoperative complications and a high rate of postoperative progression of keratoconus.

Background: The accurate measurement of the horizontal corneal white-to-white (WTW) diameter is essential and has multiple applications in the field of ophthalmology whether medical or surgical. There are many means of measuring the horizontal white-to-white, which includes the Pentacam, the IOL Master and Manual Calipers. Both the Pentacam and Manual Calipers measure the external white-to-white diameter, whereas the IOL Master measures the internal white-to-white diameter. Objective: The aim of this study is to measure the accuracy of the Pentacam white-to-white camera in measuring the horizontal corneal WTW diameter in comparison to the Manual Calipers, which is considered to be the basic standard. Patients and Methods: The study was a cross sectional one, conducted at Maghrabi Eye Hospital, Cairo, Egypt. It was conducted in accordance with the ethical standards stated by the Ethical Committee of Ain Shams University. Informed consent was obtained from each participant following the explanation of the academic nature of the study. Results: Our study compared the accuracy of the Pentacam HR to the Manual Calipers and found a strong correlation between both methods regarding all parameters. A difference of 0.44 ± 0.17 mm was found between the manual calipers and the Pentacam (HVID Automated) measurements and a lesser difference of 0.24 ± 0.27 mm when comparing the manual calipers with the Pentacam manual digital calipers. On the other hand, the difference between the 2 methods of the Pentacam measurement used was 0.19 ± 0.13 mm. All of which, showed a highly significant correlation. Conclusion: The Pentacam gives larger WTW measurements than the manual calipers as it relies on the gray scale analysis of the HVID in the iris image display.

PURPOSE:To analyze the visual and refractive outcomes of combined accelerated cross-linking with femtosecond laser intracorneal ring segment implantation for the treatment of pediatric keratoconus. MATERIALS AND METHODS:This retrospective multicenter noncomparative clinical study included 63 eyes of 37 patients (age, 9-17 years) who underwent between August and September 2016 combined cross-linking with intracorneal ring segment implantation for keratoconus. Preoperative and postoperative (6, 12, and 18 months) uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), subjective refractions, keratometry (K), and pachymetry measurements were compared. RESULTS:The postoperative spherical equivalent refraction was within ±1 D, ±2 D, and ±3 D in 19 (30.2%), 27 (42.9%), and 37 (58.8%) eyes, respectively. Only 27 eyes achieved the attempted preoperative spherical equivalent refraction. The mean spherical equivalent refraction significantly improved from -6.01 ± 2.97 to -3.13 ± 2.78 D postoperatively (P < 0.0001). The mean K average reading significantly decreased from 48.75 ± 4.25 to 46.65 ± 3.89 D postoperatively (P < 0.0001). The mean postoperative myopic, astigmatic, and spherical equivalent corrections were -2.17 ± 2.19, -1.52 ± 2.03, and -2.93 ± 2.35 D, respectively. The mean UDVA and CDVA showed significant improvements (0.89 ± 0.33 to 0.40 ± 0.28, P < 0.0001; 0.35 ± 0.31 to 0.25 ± 0.24, P = 0.004; respectively) at 18 months postoperatively. Keratoconus progression, segment migration, and segment extrusion were seen in four (6.4%), one (1.6%), and three (4.7%) eyes, respectively, probably contributing to the lower mean postoperative CDVA. CONCLUSION:Cross-linking plus is only partially effective for pediatric keratoconus. Despite some improvements in vision and keratometry measures, it resulted in complications such as keratoconus progression, segment extrusion, and segment migration that affected the vision in some patients. These findings suggest an assessment of standard epithelium-off collagen cross-linking as a sole procedure to treat pediatric keratoconus in future studies.

PURPOSE:To describe the effect of prolonging the standard suction duration during laser-assisted in-situ keratomileusis (LASIK) and its effect on flap thickness and hinge length using sub-Bowman keratomileusis (SBK) microkeratome.METHODS:Fifty-six eyes (28 patients) were included and divided into 2 groups; Group-A: eyes with flatter corneas (36 eyes, 18 patients) and mean keratometric readings ranging from 40.13 to 43.71 diopters (D). Group-B: eyes with steeper corneas (20 eyes, 10 patients) with mean keratometric readings ranging from 43.85 to 46.72 D. One-Use-Plus SBK microkeratome was used for flap creation. For right eyes, flap was created immediately once suction was built up. In left eyes, the surgeon waited for 10 s after suction was built up before flap creation. Flap hinge length and flap thickness were measured using surgical caliper and ultrasonic pachymetry, respectively.RESULTS:Statistically significant differences were observed in corneal flap hinge size between right eyes versus left eyes, with a mean of 3.98 ± 0.48 vs. 3.78 ± 0.55 mm (p < 0.001). Mean flap thickness in both eyes did not prove to be statistically significantly different with either surgical technique (90.2 ± 1.68 vs. 90.07 ± 1.44 μm, p = 0.8). Sub-group analysis of Group-A vs. Group-B revealed hinge sizes that were significantly larger in steeper corneas (p < 0.01 and p < 0.05, respectively). However, flap thickness in both groups was unaffected by surgical procedure (p = 0.5).CONCLUSIONS:Increasing suction duration increases flap hinge length and stabilizes the flap, especially in steeper corneas.

Aims The aim of the study was to evaluate the refractive, topometric and aberrometric changes in corneas with keratoconus treated with femtosecond laser intracorneal ring segment (ICRS) implantation following a proposed modified nomogram. Settings and design This is a retrospective, consecutive case series. Materials and methods ICRS implantation using the new proposed nomogram was performed in 10 eyes of seven patients with type 1 and type 2 keratoconus. Corneal tunnels were created using femtosecond laser, and KeraRings were inserted in all eyes. All cases were followed up every 3 months for 6 months using the Pentacam Phoenix system. Statistical analysis All analyses were performed with SPSS for windows 2007. Results None of our patients developed complications related to ring placement, such as migration, extrusion or infection. In this limited case series an improvement was seen in uncorrected visual acuity (P 0≤ 0.05), best spectacle corrected visual acuity (P ≤ 0.001) and refraction at 6 months (P < 0.001). Keratometric readings improved (P < 0.001), with flattening of the cornea. Corneal aberrations showed significant reduction when analysed by Zernike (P < 0.001) and Fourier analysis ( P ≤ 0.001). Corneal asphericity (Q value) also showed improvement (P < 0.05). Conclusion Femtolaser ICRS implantation using the proposed modified nomogram showed promising results in improving refraction, visual acuity, corneal topography and aberrations in patients with keratoconus.

Aim The aim of the present study was to compare the differences in visual outcomes, higher-order aberrations and corneal asphericity, as measured by Q values, in patients undergoing laser in-situ keratomileusis using wavefront-guided variable-spot size VISX CustomVue and wavefront-optimized small-spot size WaveLight Allegretto platforms. Type of study This study was designed as a randomized, prospective, single-blinded, double-armed, fellow-eye comparative study. Patients and methods A total of 100 eyes of 50 patients undergoing customized laser in-situ keratomileusis for compound myopic astigmatism were enrolled and randomly divided into two groups. Each patient underwent full ophthalmological examination; aberrometry was performed on either eye by using VISX CustomVue aberrometer and Allegretto WaveLight aberrometer. Each patient had one eye examined using the Allegretto Wave eye Q system (small-spot scanning), and the fellow eye by using VISX Star CustomVue S4 system (variable-spot scanning). All patients were given postoperative steroids, antibiotic drops and artificial tears. First day postoperative visit was scheduled to check for flap stability, and to exclude complications. Clinical examination and best corrected visual acuity, corneal imaging and aberrometry were scheduled at 1 month and 1 year later. Results Final best corrected visual acuity showed insignificant difference between the two groups (P = 0.712). The final differences between the groups were insignificant in all other parameters. Conclusion The two ablation profiles are highly comparable in treating compound myopic astigmatism.