Does collagen cross linking have any effect on retinal circulation in patients with keratoconus? An optical coherence tomography angiography (OCTA) study.

BACKGROUND: We aimed to employ Optical Coherence Tomography Angiography (OCTA) to comprehensively assess changes in the optic nerve head (ONH) and macular perfusion before and after the Corneal Collagen Cross-Linking (CCL) procedure in patients with keratoconus. METHODS: A total of 22 keratoconus patient's candidate for CCL procedures were included based on specific criteria, with meticulous exclusion criteria in place to minimize potential confounders. Participants underwent OCTA assessments of the ONH and macula using the Spectralis OCT (Heidelberg) before CCL, as well as at 1- and 3-months post-CCL. MATLAB software was utilized for image analysis. RESULTS: The mean age of the participants was 20.09 ± 6.11, including 59% male, and the mean intraocular pressure (IOP) before the surgery was 13.59 ± 2.85 mmHg. Peripapillary Retinal nerve fiber layer (ppRNFL) thickness and overall retinal thickness remained stable post-CCL. However, significant alterations were observed in macular vessel density, emphasizing regional variations in vascular response. For macular large vessel density (LVD), both superficial and deep vascular complex (SVC and DVC) demonstrated significant differences between before surgery and the 3 months post-surgery follow-up (p < 0.001 and p = 0.002, respectively). Optic nerve head markers demonstrated relative stability, except for changes in avascular complex density, which was 49.2 ± 2.2% before the surgery and decrease to 47.6 ± 1.7% three months after the operation (P-value = 0.005). CONCLUSION: While CCL appears to maintain the integrity of certain ocular structures, alterations in macular perfusion post-CCL suggest potential effects on retinal blood supply. Long-term monitoring is crucial to understand the implications of these changes, particularly in the context of conditions such as diabetes.

Prevalence and risk factors of keratoconus (including oxidative stress biomarkers) in a cohort study of Shiraz university of medical science employees in Iran.

BACKGROUND: To determine the prevalence of keratoconus in Shiraz University of Medical Sciences Employees and the related risk factors including oxidative stress biomarkers. METHODS: 2546 subjects' mean age ± SD, 40.35 ± 6.70 (46% male) were recruited. All participants underwent objective refraction using auto-refractometer and retinoscopy, followed by subjective refraction, and bio-microscopy. Pentacam imaging was performed for the detected keratoconus patients. The prevalence of keratoconus and frequency of the visual impairment among keratoconus cases were evaluated. Potential risk factors of sex, age, family history of keratoconus, body mass index ≥ 30 kg/m2, serum levels of glucose ≥ 100 mg/d, low-density-lipoprotein-cholesterol (LDL) ≥ 110 mg/dL, high-density-lipoprotein-cholesterol ≤ 40 mg/d, and triglycerides ≥ 150 mg/dL in the blood were evaluated. RESULTS: The prevalence of keratoconus at least in one eye was 0.98% (95% CI: 0.6- 1.4%). The best corrected visual acuity in the keratoconus group was 0.06 ± 0.1 and the rest of the population was 0.01 ± 0.07 logMAR (p < 0.001). The frequency of visual impairment in the keratoconus group was zero. Odds ratios of the family history of keratoconus (21.00, 95% CI: 9.00-48.00, p < 0.001) and LDL ≥ 110 mg/dL (3.00, 95% CI: 1.20-6.40, p = 0.01) were significant. CONCLUSIONS: Keratoconus is rare and is not considered a risk factor for visual impairment. A family history of keratoconus and elevated serum LDL levels are contributing risk factors, suggesting an inflammatory background for the disease. Serum levels of LDL ≥ 110 mg/dL in the blood increased the risk of keratoconus three folds.

Therapeutic Implications of Curcumin in the Treatment of Inflammatory Eye Diseases: A Review.

Curcumin is the main active constituent of the medicinal plant Curcuma longa L., used traditionally as a medicinal spice in several ancient civilizations. Different preclinical and clinical studies support the anti-inflammatory properties of curcumin in various inflammatory diseases. As inflammation has an essential role in the pathophysiology of many ocular diseases, curcumin has been suggested as a promising therapeutic agent with anti-inflammatory properties. Based on the extent of experimental and clinical evidence, curcumin can exert protective effects against the corneal, uveal, retinal, optic nerve, orbital, and lacrimal gland inflammatory disorders. Herein, the available literature on the beneficial effects of curcumin in inflammatory eye diseases is reviewed. The limitations and future directions of these investigations are also discussed.

Vision-related Quality of Life after Bilateral Implantation of Monofocal and Multifocal Intraocular Lenses.

PURPOSE: To evaluate vision-related quality of life in two sets of patients after routine cataract surgery implanting with traditional versus multifocal intraocular lens (IOLs). METHODS: In a cross-sectional prospective study, 58 and 33 candidates for cataract surgery were divided into traditional (Acrysof SN60WF, Alcon Laboratories, Inc) and multifocal IOL (AcrySof IQ PanOptix IOL TFNT00, Alcon Laboratories, Inc.) groups, respectively. The primary outcome was VFQ-25 scores. The secondary outcomes were making comparisons between the two IOL types in the near vision and the driving items. RESULTS: mean patients' age in traditional and multifocal IOL groups was 60.85 ± 7.40 (55% female) and 59.85 ± 8.95 (36% female) years, respectively. The mean VFQ-25 total scores in traditional and multifocal IOL groups before and after surgery were 63.69 ± 4.95 and 72.15 ± 9.66, and 98.08 ± 0.70 and 95.70 ± 1.30, respectively (P = 0.001 & 0.001). The mean scores of night driving in traditional and multifocal IOL groups were 38.79 ± 20.50 and 44.35 ± 21.12 (P = 0.1) before surgery which improved to 97.41 ± 7.68 and 56.45 ± 11.12 after surgery, respectively (P = 0.001). The mean scores of near vision in traditional and multifocal IOL groups were 46.83 ± 10.56 and 50.53 ± 8.58 (P = 0.2) before surgery which improved to 89.94 ± 4.87 and 100.00 ± 0.00 after surgery, respectively (P = 0.001). CONCLUSION: Vision-related quality of life after cataract surgery with either type of traditional or multifocal (PanOptix) IOLs improved to an excellent level. Traditional IOLs provided more satisfaction in nighttime driving while multifocal IOLs provided increased satisfaction in near and intermediate vision.

Agreement of wavefront-based refraction, dry and cycloplegic autorefraction with subjective refraction

Purpose: To evaluate the agreement of dry, and cycloplegic autorefraction and wavefront-based refraction with subjective refraction.Method: 83 subjects aged 19–57 years were included in this cross-sectional study. Refractive status was determined using four methods including subjective refraction, wavefront-based refraction, dry and cycloplegic autorefraction. Refractive data were recorded as sphere, cylinder and spherical equivalent (SE). Power vector components were used to compare the astigmatism obtained using the different methods of refraction.Results: The more negative spherical, cylindrical and SE components were obtained using dry autorefraction, wavefront-based refraction and dry autorefraction, respectively. The less negative spherical, cylindrical and SE components were obtained using cycloplegic autorefraction, subjective refraction and cycloplegic autorefraction, respectively. Considering the spherical component, there was a statistically significant hyperopic shift (0.12 ± 0.29 D, p = 0.001) with cycloplegic autorefraction and a significant myopic shift (−0.17 ± 0.32 D, p < 0.001) with dry autorefraction compared to subjective refraction, while the difference between wavefront-based and subjective refraction was not significant statistically (p = 0.145). The calculated cylindrical component using subjective refraction showed statistically significant difference with dry auto-refraction (p < 0.001), cycloplegic auto-refraction (p = 0.041) and wavefront refraction (p < 0.001). The highest correlation with subjective refraction in sphere, cylinder and SE was observed for cycloplegic auto-refraction (rs = 0.967), dry auto-refraction (rs = 0.983) and cycloplegic auto-refraction (rs = 0.982), respectively.Conclusions: As subjective refraction is gold standard in our study, sphere in cycloplegic auto-refraction and astigmatism in dry auto-refraction showed better agreement and correlation. (AU)

Agreement of wavefront-based refraction, dry and cycloplegic autorefraction with subjective refraction.

PURPOSE: To evaluate the agreement of dry, and cycloplegic autorefraction and wavefront-based refraction with subjective refraction. METHOD: 83 subjects aged 19-57 years were included in this cross-sectional study. Refractive status was determined using four methods including subjective refraction, wavefront-based refraction, dry and cycloplegic autorefraction. Refractive data were recorded as sphere, cylinder and spherical equivalent (SE). Power vector components were used to compare the astigmatism obtained using the different methods of refraction. RESULTS: The more negative spherical, cylindrical and SE components were obtained using dry autorefraction, wavefront-based refraction and dry autorefraction, respectively. The less negative spherical, cylindrical and SE components were obtained using cycloplegic autorefraction, subjective refraction and cycloplegic autorefraction, respectively. Considering the spherical component, there was a statistically significant hyperopic shift (0.12 ±â€¯0.29 D, p = 0.001) with cycloplegic autorefraction and a significant myopic shift (-0.17 ±â€¯0.32 D, p < 0.001) with dry autorefraction compared to subjective refraction, while the difference between wavefront-based and subjective refraction was not significant statistically (p = 0.145). The calculated cylindrical component using subjective refraction showed statistically significant difference with dry auto-refraction (p < 0.001), cycloplegic auto-refraction (p = 0.041) and wavefront refraction (p < 0.001). The highest correlation with subjective refraction in sphere, cylinder and SE was observed for cycloplegic auto-refraction (rs = 0.967), dry auto-refraction (rs = 0.983) and cycloplegic auto-refraction (rs = 0.982), respectively. CONCLUSIONS: As subjective refraction is gold standard in our study, sphere in cycloplegic auto-refraction and astigmatism in dry auto-refraction showed better agreement and correlation.

Glutathione S-Transferase Omega-2 and Transforming Growth Factor-ß1 Polymorphisms in Iranian Glaucoma Patients.

BACKGROUND: To investigate the association of glutathione s-transferase omega 2 (GSTO2) (142N > D) and transforming growth factor-ß1 (TGF-ß1) (869T > C) gene polymorphisms on the pathogenesis of two common types of glaucoma (including primary open-angle glaucoma (POAG) and chronic angle-closure glaucoma (CACG)) in the Iranian population. METHODS: A total of 100 glaucoma patients (60% males and 40% females with an age mean ± SD of 34.66 ± 14.25 years; 56 cases of POAG and 44 cases of CACG) were enrolled in this study. GSTO2 (142N > D) and TGF-ß1 (869T > C) polymorphisms were evaluated by PCR-based methods in patients and controls. RESULTS: At locus GSTO2 (142N > D), the odds of ND genotype with respect to DD and NN genotypes were 1.55 and 2.08 times higher in POAG and CACG patients compared to those of patients in the control group (95% CI1: 0.80-2.98; 95% CI2: 1.00-4.33) which was statistically significant in CACG patients. However, the odds of DD and NN genotypes against the reference genotype in two patients group were not statistically significant as compared to those of patients in the control group. There was a significant association between the ND genotype and male patients (OR = 2.28, 95% CI: 1.06-4.92). The analysis of TGF-ß1 (869T > C) polymorphisms showed no significant difference between the genotypes of TGF-ß1 (869T > C) polymorphisms in patients and control groups; however, the CT genotype of TGF-ß1 significantly differed between female controls and patients (OR = 0.42, 95% CI: 0.18-0.96). CONCLUSION: The presented results revealed that there was a significant association between the ND genotype of GSTO2 and the pathogenesis of glaucoma. Furthermore, this genotype can be considered as a sex-dependent genetic risk factor for the development of glaucoma. In contrast, the CT genotype of TGF-ß1 is suggested to be a protective genetic factor against the pathogenesis of glaucoma.

Comparison of endotracheal intubation, laryngeal mask airway, and I-gel in children undergoing strabismus surgery.

BACKGROUND: Insertion of the advanced airway during induction of general anesthesia can cause undesirable sympathetic stimulation such as increased intraocular pressure (IOP) and hemodynamic parameters. In this study, we compared insertion of three different advanced airway devices; endotracheal tube (ETT), laryngeal mask airway (LMA) and I-gel in terms of IOP, hemodynamic changes and postoperative nausea and vomiting (PONV) following induction of general anesthesia with propofol and remifentanil in children undergoing strabismus surgery. MATERIALS AND METHODS: A total of 90 children (5.68 ± 1.49 years old) were randomly assigned to one of the three groups, ETT, LMA, or I-gel insertion as advanced airway devices IOP and also hemodynamic variables were measured before (T0 and T1) and immediately after (T2) the insertion of these airway devices, although 2 min (T3) and 5 min (T4) after it. PONV was assessed about 2 h after the completion of surgery in the recovery room. RESULTS: The mean arterial pressure (MAP), IOP, and systolic and diastolic blood pressures were significantly different between the three groups immediately (T2), 2 min (T3), and 5 min (T4) after the insertion of airway devices. The heart rate (HR) was significantly different between the three groups in all measurement times except of T0. Within-group comparisons showed that the three groups had significant changes in MAP, IOP, HR, systolic and diastolic pressure before and after airway insertion (T1 and T2). The trend in the LMA and ETT groups was descending-ascending-descending, whereas in the I-gel group, it was quite descending. There was no significant difference among the three groups in terms of PONV. CONCLUSION: As a result, our study showed that, compared with LMA and ETT, the I-gel had less impact on undesirable stress responses and seems to be superior to LMA and ETT in children undergoing strabismus surgery.

Long-term Outcomes of Collagen Crosslinking for Early Keratoconus.

PURPOSE: To evaluate the long-term outcomes of collagen crosslinking in early keratoconus. METHODS: Thirty eyes of twenty patients with early keratoconus were enrolled. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), objective refraction, subjective refraction, corneal topography and pachymetry were assessed before and 3, 6, 12 months and 9 years after performing collagen crosslinking surgery. RESULTS: The patients' mean age was 31.2 ± 5.59 years at nine-year follow-up (range, 25-44 years). The means of preoperative UCVA and BSCVA were 0.57 ± 0.34 and 0.15 ± 0.12 logMAR, respectively, and these values remained stable at the final follow-up (P = 0.990 and P = 0.227, respectively). The mean objective spherical equivalent decreased considerably from -6.00 ± 4.05 D preoperatively to -5.22 ± 3.71 D at the final follow-up (P < 0.05). The mean subjective spherical equivalent was -4.25 ± 2.87 D preoperatively and this value was stable at the last follow-up (P = 0.92). No considerable difference was found between the post- and preoperative mean objective cylinder values (P = 0.34). The mean subjective cylinder value changed significantly from -4.05 ± 1.85 D preoperatively to -3.1 ± 1.42 D at the final follow-up (P < 0.05). The mean central corneal thickness was 496.97 ± 45.95 µm preoperatively and this value was stable at nine-year follow-up (P = 0.183). No significant difference was found between the pre- and postoperative mean maximum and mean minimum corneal curvature values (P = 0.429 and P = 0.248, respectively). There were no significant postoperative complications. CONCLUSION: Corneal crosslinking in early keratoconus seems to be a safe procedure that can effectively stabilize UCVA, BSCVA, subjective SE and CCT, while improving objective spherical equivalent.

Cycloplegic Effects on the Cylindrical Components of the Refraction.

It is important to predict which astigmatic patients require separate refraction for near vision. This study compared cylindrical components changes by cyclopentolate 1% for the low and high amount of astigmatism. The right eyes of 1014 healthy individuals (307 males and 707 females) with cylindrical refractive power more than -0.5 diopter on autorefractometer were selected. Both male and female patients in the age range of 17-45 years were refracted before and after cycloplegia, using 1% cyclopentolate. All volunteers were classified into 2 subgroups including the lower astigmatism group (-2.25 to -0.50) and the higher astigmatic group (-2.50 to over). Alpines' method was used to compare the effect of cycloplegic drop on cylindrical power. The mean age in the lower astigmatism group (29.58; 95% CI: 29.18 to 29.99 years) was not significantly different from the higher astigmatic group (29.85; 95% CI: 29.07 to 30.62) and there were no significant differences in gender between these two groups (P=0.54). Differences between wet and dry refraction in J0 (-0.03; 95% CI:-0.06 to -0.008) and J45 (-0.03; 95% CI:-0.06 to -0.01) were significant only in the higher astigmatic group. Axis changes by the cycloplegic drop in the lower astigmatism group were 3.51 (CI: 3.22 to 3.81) and axis changes by the cycloplegic drop in the higher astigmatism group were 2.21 (CI: 1.73 to 2.49). In patients with a lower amount of astigmatism (-2.25 to -0.50), additional near subjective refraction could be done for precise determination of axis and in patients with a higher amount of astigmatism (-2.50 to over), near subjective refraction might be done for precise determination of power.

Correlation between keratometry and corneal incision before and after phaco surgery.

INTRODUCTION: Cataract is a common cause of vision loss and blindness in humans. After surgical management of cataract, all efforts should be focused on reducing postoperative astigmatism thus providing an excellent vision to patients. AIM: To determine the relationship between corneal incision and refraction changes before and after phacoemulsification surgery in 300 patients undergoing cataract surgery in Khatam hospital in Mashhad, Iran from January 2017 to April 2018. MATERIALS AND METHODS: Three hundred patients (144 women and 156 men) with cataract undergoing phacoemulsification surgery were recruited in this cross-sectional study. Refraction, keratometry and visual acuity measurement were performed before surgery. Then, a steep-based incision in the cornea was made without stitches. A 3.2 mm corneal incision was made at two supratemporal and temporal sites. The patients were followed-up for one and six months, and one year after surgery monitoring their vision and refraction, and performing keratometric measurements. RESULTS: The mean age of the patients was 65.7±9.54 years (age range, 42-84 years). No major complications were observed. The greatest mean of changes in corneal power was in the supratemporal incision (1.28±0.6). Keratometry had a significant relation with the incision (p.

Intracorneal Stromal Ring Can Affect the Biomechanics of Ectatic Cornea.

PURPOSE: The biomechanical properties of ecstatic cornea undergo changes. This study evaluates the biomechanical changes of ecstatic cornea after implantation of two types of intracorneal stromal ring (ICR). METHODS: For doing this prospective cross-sectional study, 32 patients with keratoconus (KCN) were randomly divided into two 16-member groups (group I: MyoRing, group II: KeraRing). The main inclusion criteria were transparent cornea with no scar in the central part, corneal thickness >450 µ in the incision region, keratometry within 48-52 diopters, and progressive course of corneal thinning. Biomechanics of the cornea was evaluated by "ORA" and "Corvis" devices. All of the data were recorded and analyzed before implantation of the rings and 6 months thereafter. RESULTS: The mean ages of patients of groups I and II were 26 ± 6.55 and 33.86 ± 8.5, respectively. The postoperative change of sphere refraction was significant in both groups. However, reduction in the astigmatism was significant only in group I. In addition, the change of flat meridian keratometry (Kf) was significant before and after ring implantation in group I, unlike group II. The changes in CH and CRF parameters (ORA) were not significant in either group before and after the operation. Besides, only HRC parameter (Corvis) decreased significantly in both groups before and after the operation. CONCLUSION: Both MyoRing and KeraRings have positive effects on the biomechanics of cornea at least during the first year after implantation. Comparison of these two types of ICR did not show significant differences in Corvis and ORA parameters.

Corneal Collagen Cross-Linking Using Epithelium Disruptor Instrument in Progressive Keratoconus.

PURPOSE: To compare the effects of accelerated corneal collagen cross-linking (CXL) in progressive keratoconus (KCN) patients via epithelium removal and transepithelial techniques, using Daya Disruptor (Duckworth and Kent, Hertfordshire, UK). METHODS: This study is a double-blinded, randomized clinical trial. Patients with documented bilateral progressive KCN were randomized into two groups: one eye underwent epithelium removal (Group 1), and the fellow eye underwent epithelium disruption (Group 2). The primary outcomes were best corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA), Scheimpflug-extracted keratometric indices, and anterior segment-optical coherence tomography-derived epithelial thickness profiles. These parameters were evaluated before and 12 months after CXL. RESULTS: Sixty-four eyes from 34 patients with progressive KCN (34 eyes in the epithelium-removal group and 30 eyes in the epithelium-disruption group) were included. The mean ± standard deviation (SD) of age was 23.4 ± 3.8 years in the epithelium-removal group and 23.2 ± 3.5 years in the epithelium-disruption group. The mean ± SD of the preoperative spherical equivalent (SE), front maximum keratometry (K-max), back K-max, thickness of thinnest point, and corneal apex thickness were - 2.9 ± 3.0 diopter (D) and - 3.7 ± 3.1 D (P = 0.183), 53.8 ± 5.15 D and 54.4 ± 5.53 D (P = 0.653), -6.63 ± 2.40 D and - 6.68 ± 2.48 D (P = 0.131), 459.2 ± 37.4 µm and 460.8 ± 32.7 µm (P = 0.708), 470.5 ± 37.7 µm and 469.7 ± 33.1 µm (P = 0.679), and 55.4 ± 4.97 µm and 54.6 ± 7.16 µm (P = 0.767) in the epithelium-removal and epithelium-disruption groups, respectively. The mean ± SD changes of the UCVA and BCVA 12 months after CXL were - 0.1 ± 0.11 and - 0.02 ± 0.18 and - 0.04 ± 0.12 and - 0.02 ± 0.14 in the epithelium-removal and epithelium-disruption groups, respectively. No statistically significant improvement was observed in the UCVA and BCVA between the two groups (P = 0.868 and P = 0.937, respectively). The mean ± SD changes of the SE, superior epithelial thickness, corneal apex thickness, and thickness of thinnest point 12 months after CXL were - 0.21 ± 1.1 D and + 0.32 ± 1.6 D (P = 0.0001), -0.08 ± 0.26 µm and + 0.03 ± 0.33 µm (P = 0.028), -23 ± 11 µm and - 2 ± 6 µm (P = 0.0001), and - 25 ± 8 µm and - 3 ± 7 µm (P = 0.0001) in the epithelium-removal and epithelium-disruption groups, respectively. CONCLUSIONS: This study showed that the epithelium-disruption CXL using Daya has a similar potential for halting KCN progression as the epithelium-removal CXL. However, regarding the 12-month changes, the epithelium-disruption CXL is superior to the epithelium-removal CXL in the SE and corneal pachymetry.

Comparison of the effects of 1/10,000 and 1/100,000 concentrations of intracameral epinephrine on corneal endothelium and macular thickness after uncomplicated phacoemulsification.

PURPOSE: To evaluate the changes in the corneal endothelial cell parameters and macular thickness after intraocular application of epinephrine [Formula: see text] and epinephrine[Formula: see text]. METHODS: In this study, 210 eyes from 210 patients with age-related cataracts who underwent uncomplicated surgery were included. For all patients, specular microscopy of the corneal endothelium and macular OCT were performed before surgery and 3 months after the surgery. Patients were divided randomly into three groups: without drug (control group), epinephrine [Formula: see text], and epinephrine[Formula: see text]. Three months after the surgery, specular microscopy of the cornea and macular OCT measurements were performed. Measurements were compared between the three groups. Postoperative measurements were also compared with those measurements obtained before surgery. RESULTS: All the three groups showed a statistically significant decrease in the endothelial cell density after surgery; the reduction in endothelial cell density in the epinephrine [Formula: see text] group was significantly more than those of the other two groups (P value < 0.001). Hexagonality of endothelial cells was significantly reduced in the three groups after the surgery, the epinephrine [Formula: see text] group had more reduction compared with both other groups (P values < 0.001). All the three groups showed a statistically significant increase in the macular thickness after the surgery (P values < 0.001). The mean increase in the macular thickness in the epinephrine [Formula: see text] group was significantly more than those of the other two groups (P values < 0.05). CONCLUSION: Toxicity of the drug to many endothelial cell parameters and macula was reduced with decreasing concentration of epinephrine to [Formula: see text].

Fourier Analysis of Keratometric Data in Epithelium Removal versus Epithelial Disruption Corneal Cross-linking.

PURPOSE: To compare epithelium-removal and epithelium-disruption corneal crosslinking (CXL) methods in Fourier analysis of keratometric data and clinical outcomes. METHODS: In this double masked randomized clinical trial, each eye of 34 patients with bilateral keratoconus was randomly allocated to either the epithelium-removal or epithelium-disruption CXL treatment groups. Ocular examination, refraction, uncorrected and best spectacle-corrected visual acuity (UCVA and BSCVA, respectively) measurements, and Pentacam imaging (keratometry, pachymetry, and Fourier analysis) were performed at baseline and at six-month follow-up period. RESULTS: Patients' mean age was 23.3 ± 3.6 years. The preoperative thickness of the thinnest point was 459.20 ± 37.40 µm and 455.80 ± 32.70 µm in the epithelium-removal and epithelial-disruption CXL groups, respectively (P > 0.05). The corresponding figures were 433.50 ± 33.50 µm and 451.90 ± 39.70 µm, respectively, six months after the treatment (P = 0.0001). Irregularity component of the fourier analysis was 0.030 ± 0.016 µm in the epithelium-removal group and 0.028 ± 0.011 µm in the epithelium-disruption group preoperatively (P > 0.05). This measurement was 0.031 ± 0.016 µm and 0.024 ± 0.009 µm, respectively at month 6 (P = 0.04). The epithelium-disruption CXL group had better results in terms of the thickness of the thinnest point and the irregularity component as compared to the epithelium-removal group. The two study groups were comparable in spherical equivalent, mean keratometry, UCVA, BSCVA, or other Fourier analysis components (spherical R min, spherical eccentricity, central, peripheral regular astigmatism, and maximum decentration) (P > 0.05). CONCLUSION: This study shows that epithelium-disruption CXL is superior to epithelium-removal CXL regarding the short-term changes in pachymetry and corneal irregularity. Other evaluated parameters were comparable between the two techniques.

Corneal Cross-linking as an Adjunct for The Management of Refractory Fungal Keratitis.

PURPOSE: To evaluate the effectiveness of ultraviolet (UV)-A/Riboflavin corneal cross-linking (CXL) for the treatment of the refractory cases of fungal keratitis. METHODS: In this prospective interventional study, 9 patients with the diagnosis of fungal keratitis that were referred to our emergency eye center were included. These patients were resistant to conventional treatment and underwent therapeutic UV-A/Riboflavin CXL. Response to the treatment was considered as good if rapid epithelialization and rapid decrease in stromal infiltration was occurred after PACK-CXL, and poor when the emergency transplantation was necessary to eradicate the infection. RESULTS: Nine patients treated with CXL due to recalcitrant fungal keratitis. Culture of the corneal scrapings showed Aspergillus species in 4 patients, Candida albicans in 1 patient and Fusarium species in the remainder of them. CXL was performed from 1 to 20 days after the presentation of corneal ulcers (Mean: 9.12 ± 4.02; range: 5-20 days). Postoperatively, the mean time to epithelialization was 14.25 ± 2.38 days, and mean time to resolution of stromal infiltration was 22.5 ± 7.29 days, in responsive cases. Four out of 9 eyes showed good response, and five patients showed no response, and corneal transplantation was performed to eradicate the infection. There was no statistically significant difference in mean depth of infiltration and mean size of ulcer between responsive and unresponsive patients (P = 0.86 and 0.08, respectively). CONCLUSION: Although UV-A/Riboflavin CXL is not a definite treatment for all of the fungal keratitis, it seems promising in the management of some refractory cases.

Sensitivity and Specificity of Belin Ambrosio Enhanced Ectasia Display in Early Diagnosis of Keratoconus.

PURPOSE: Early diagnosis of keratoconus disease (KCN) is the first priority in the preoperative evaluations of refractive surgery (RS).The aim of this study was to investigate the correlation between findings of Belin Ambrosio enhanced ectasia display (BAD) software and conventional corneal imaging (Orbscan and topography) in the early diagnosis of KCN. METHODS: For conducting this cross-sectional study, a total of 1000 eyes were selected from 500 patients that underwent the myopic photorefractive keratectomy surgery and were compared in four study groups during the years 2017-2018. In group 1, all topography, Orbscan, and BAD criteria were normal (65.8%).In contrast, in Group 2, at least one of the topography or Orbscan criteria as well as at least one BAD criterion (12.6%) were abnormal. In Group 3, the eyes had normal Orbscan and topography criteria with at least one abnormal BAD criterion (18.5%). Also, in Group 4, the patients had at least one abnormal Orbscan or topography criterion, but all BAD criteria (3.1%) were normal. Thickness of the thinnest point (TP) of cornea was compared in Pentacam and topography. Data analysis was done by SPSS software (version 21). RESULTS: BAD criteria were normal in 78.5% of all eyes with normal topography and Orbscan criteria (specificity). BAD criteria were also abnormal in 80.2% of eyes (sensitivity). There was also no significant difference between TP in Orbscan and Pentacam. CONCLUSIONS: BAD criteria had a relatively acceptable sensitivity and specificity, compared with conventional Orbscan and topography criteria. Thus, BAD criteria can be more effective in the early diagnosis of KCN.

Predictors of Successful Outcome following Intrastromal Corneal Ring Segments Implantation.

Purpose: To assess the preoperative visual, refractive, corneal topo/tomographic, aberrometric and biomechanical parameters as predictive factors of a successful outcome 6 months following intrastromal corneal ring segments implantation. Methods: Sixty-eight keratoconus eyes implanted with Keraring using femtosecond laser technology were assessed. The preoperative assessed parameters included uncorrected and corrected distance visual acuity (UDVA & CDVA), refraction, placido-disk based topography using TMS-4, Scheimplfug tomography using Pentacam HR, corneal biomechanical assessments using Ocular Response Analyzer (ORA) and the wavefront analysis using i-Trace aberrometer. Other variables were type of astigmatism based on orientation of the steep meridian, keratoconus staging based on the Amsler-Krumeich classification and the difference between the axes of refractive astigmatism, topographic astigmatism and comatic aberration based on a difference less or more than 30°. The success criterion was defined based on CDVA, a post-operative CDVA improvement at least two lines were considered as a success and otherwise were recognized as a failure following Keraring implantation. Results: Only UDVA, coincidence of the most elevated points on the front and back corneal surfaces and the difference between UDVA and CDVA showed significant difference between the eyes with successful outcomes and those with unsuccessful results (P < 0.05). Although corneal curvature and astigmatism were higher and corneal thickness was lower in the unsuccessful group, differences were not statistically significant. Conclusion: It is expected that the greater difference between the preoperative uncorrected and corrected distance visual acuity (Δ UDVA-CDVA) and more coincidence of the most elevated points in the two corneal surfaces on the elevation maps increase the rate of successful outcome following the Keraring implantation. Abbreviations: ICRS: intrastromal corneal ring segments; UDVA: uncorrected distance visual acuity; CDVA: corrected distance visual acuity; logMAR: logarithm of minimum angle of resolution; SE: spherical equivalent; IOP: intra-ocular pressure; Km: mean keratometry; CA: corneal astigmatism; WTR: with-the-rule; ATR: against-the-rule; OBL: oblique; SB: symmetric bow-tie; AB: asymmetric bow-tie; IS: inferior steepening; SRAX: skewed radial axis; Q: asphericity (Q-value); CCT: central corneal thickness; CTP: corneal thinnest point; ORA: ocular response analyzer; CH: corneal hysteresis; CRF: corneal resistance factor; HOAs: higher-orders aberrations; RMS: root mean square; SD: standard deviation; CI: confidence interval.

Association Between Advanced Keratoconus and Serum Levels of Zinc, Calcium, Magnesium, Iron, Copper, and Selenium.

PURPOSE: To investigate the possibility of an association between serum levels of zinc (Zn), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), and selenium (Se) and advanced keratoconus (KCN). METHODS: In this study, 50 patients with advanced KCN and 50 control subjects were included. Plasma levels of Zn, Ca, Mg, Fe, Cu, and Se were compared between the groups. RESULTS: Mean ± SD age of the patients in the case and control groups was 29.3 ± 3.5 and 28.9 ± 5.9 years, respectively (P = 0.669). Among serum parameters, there were no statistically significant differences between the 2 groups in serum levels of Ca, Mg, and Fe (P > 0.05), whereas serum levels of Zn and Cu were significantly lower in the case group than the control group [65.92 ± 7.90 vs. 87.36 ± 13.64 µg/dL and 78.48 ± 11.96 vs. 116.34 ± 20.87 µg/dL, respectively (both P < 0.001)] as well as the serum level of Se [79.76 ± 19.16 vs. 87.41 ± 15.91 µg/dL (P = 0.032)]. CONCLUSIONS: The lower serum levels of Zn, Cu, and Se in patients with advanced KCN compared with healthy controls indicate the possible role of antioxidants in the etiopathogenesis of KCN, which points to early treatment of this progressive degenerative disease with supplementation therapy, rather than keratoplasty techniques.

Vision-Related Quality of Life in Iranian Patients With Keratoconus: National Eye Institute Vision Function Questionnaire-25.

BACKGROUND: Use of patient-reported outcomes to evaluate the impact of ocular conditions on quality of life (QoL) is rising. Hence, the aims of this study were to determine the impact of keratoconus on QoL, and assess the National Eye Institute of the United States Vision Function Questionnaire (NEI-VFQ) performance in an Iranian population. METHODS: From November 2016 to June 2017, patients with keratoconus definitive diagnosis for more than one year who were being routinely followed at a cornea clinic were recruited. The NEI-VFQ-25 was administered during a face-to-face interview. Ocular examinations comprised best-corrected visual acuity (BCVA) was logged monocularly and binocularly, anterior segment biomicroscopy, refraction, and corneal topography. Keratoconus severity was graded based on steep keratometric (K) reading values. A group of 30 age- and sex-matched subjects with other ocular diseases (except keratoconus) were selected randomly from the cornea clinic. P<0.05 was considered as significant. RESULTS: The mean age of participants was 28.7±7.6 years. The lowest NEI-VFQ subscale scores were related to ocular pain, general vision, mental health, and role difficulty. Almost all NEI-VFQ scores in patients were statistically significant less than mean score of the control group. Composite and all subscales NEI-VFQ scores were lower significantly among patients with higher disease duration (≥5 years). Among clinical data, patients with BCVA ≥0.5 in the better eye had significantly lower NEI-VFQ composite score. Severe keratoconus patients (steep K reading ≥52) had lower NEI-VFQ scores in mental health and dependency subscales (P<0.05). The overall and subscales Cronbach α was above 0.7. CONCLUSION: Iranian patients with keratoconus had physical, emotional, and social impairment in QoL. The NEI-VFQ-25 might be applicable in further studies.