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.

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.

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.

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.

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].

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.

Changes in corneal thickness and corneal endothelial cell density after phacoemulsification cataract surgery: a double-blind randomized trial.

BACKGROUND: Age-related cataract is a leading cause of visual impairment, considered a global health burden, it is responsible for over 47% of blindness worldwide. Surgical intervention is usually the treatment of choice and phacoemulsification cataract surgery with implantation of an intraocular lens is the most common procedure, which may have several complications. OBJECTIVES: To determine the effects of phacoemulsification surgery on corneal endothelial cell density and corneal thickness in patients undergoing cataract surgery. METHODS: The present study was conducted on patients diagnosed with immature senile cataract requiring surgical intervention from November 2013 to 2014 in Khatam al Anbia Hospital (a tertiary ophthalmology center). Physical examination included best-corrected visual acuity using the Snellen chart, refraction, slit-lamp bio-microscopy for anterior chamber evaluation, keratometry, Goldman tonometry, gonioscopy, and dilated indirect ophthalmoscopy, pachymetry, specular microscopy and biometry. Surgery was performed by similar method and technique in all patients. The change in the corneal endothelial cell count or density and central corneal thickness (CCT) number were compared preoperatively and one day, one week, one month, and three months post-operatively. RESULTS: A total of 92 eyes of 85 patients (43 females and 42 males with mean age of 62.1±12.2 years) were studied. Patients' visual acuity improved (log MAR: 1±0.5 preoperatively to 0.45±0.34 post-operatively) (p=0.001). There was 11.4% endothelial cell loss (ECL) and significant decrease in ECC (from 2,791.15±99.86 to 2,472.87±472.14) (p=0.04). The central corneal thickness increased significantly (from 530.47±2.60 to 540.91±36.07). Diabetic patients (12.9%) had a statistically significant higher ECL rate after phacoemulsification (14.6% versus 8.7% respectively, p=0.002). CONCLUSION: Phacoemulsification resulted in significant corneal endothelial damage, which is particularly important in patients with a borderline reservoir of endothelial cell, such as diabetic patients, which highlights the necessity of refining the current surgical methods and instruments to minimize the endothelial damage. TRIAL REGISTRATION: The trial was registered in the Thai clinical trial registry (http://www.clinicaltrials.in.th) with the ID: TCTR20171122001. FUNDING: The study was supported by a research grant of Mashhad University of Medical Sciences.

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.

The role of amniotic membrane extract eye drop (AMEED) in in vivo cultivation of limbal stem cells.

BACKGROUND: Limbal stem cell transplantation (LSCT) is the definitive treatment for total limbal stem cell deficiency (LSCD). This study evaluates the anatomical and visual outcomes of a surgical technique supplemented by amniotic membrane extract eye drop (AMEED) for in vivo cultivation of limbal stem cells (LSCs). METHODS: One small limbal block (2 × 1 mm) harvested from the contralateral healthy eye was transferred to the diseased eye, which had been already covered by cryopreserved amniotic membrane (N = 20). The patients were categorized into case and control groups. AMEED was administered postoperatively only for patients in the case group (N = 14). Sequential penetrating keratoplasty (PKP) was performed in 4 eyes of the case group for optical clarity. Visual acuity, epithelial healing, corneal clarity and regression of conjunctivalization/vascularization were evaluated after surgery. The corneal buttons of post-PKP eyes were evaluated for LSC markers. RESULTS: In the case group, the mean corrected distance visual acuity (CDVA) was 20/400 before surgery, which improved to 20/40 and 20/50 at the last follow-up in eyes with and without PKP, respectively. Epithelial defects healed in all eyes of the case group during 2 weeks after surgery. Corneal conjunctivalization/vascularization regressed dramatically in all patients of the case group 2-3 months after surgery. In PKP cases, all transplanted corneas were clear at the last follow-up. LSC markers were expressed on the surface of all trephined corneal buttons. All eyes in the control group developed persistent epithelial defect. CONCLUSION: This study suggests that amniotic membrane extract may be helpful for in vivo cultivation of limbal stem cells.

Midterm outcomes of penetrating keratoplasty after cultivated oral mucosal epithelial transplantation in chemical burn.

PURPOSE: To evaluate the midterm outcomes of penetrating keratoplasty (PKP) after cultivated oral mucosal epithelial transplantation (COMET) in patients with bilateral total limbal stem cell deficiency (LSCD) due to chemical burn. METHODS: In this prospective interventional nonrandomized case series, optical PKP was performed in patients with severe stromal opacity after successful COMET. Main outcome measures were stability of the ocular surface, visual acuity improvement and corneal graft survival. RESULTS: Fourteen eyes of 14 patients with successful COMET were included. Time interval between PKP and COMET was 7.6 ± 1.3 months (6-9 months). Mean follow-up period was 28.2 ± 8 months (14-40 months, median 30 months). Epithelial healing was complete after 7 days in all eyes. Thirteen eyes had stable ocular surface without epithelial defect at final examination. The corneal surface had been covered by a transparent epithelium without significant neovascularization. Persistent epithelial defect developed in one eye 3 months after PKP which was considered as graft failure. Best-corrected visual acuity increased from 2.67 ± 0.08 LogMAR preoperatively to 0.64 ± 0.27 LogMAR after PKP (P < 0.001). Endothelial rejection occurred in four patients and was successfully managed by systemic and topical corticosteroids. Overall and rejection-free graft survival rates were 92.9 and 69.2%, respectively. CONCLUSION: PKP after COMET is a successful procedure which can be used to restore visual function in cases with bilateral total LSCD associated with severe stromal opacity due to chemical burns.

Stromal cell derived factor-1, CXCR4 and CXCR7 gene transcripts in pterygia.

PURPOSE: Pterygium is a pathologic process with angiogenic and tumor cell like characteristics. Chemokine and chemokine receptors may contribute to the formation and growth of pterygia. The aim of this study was to assess the expression of stromal cell derived factor (SDF)-1, as an angiogenic chemokine, and its receptors, CXCR4 and CXCR7, gene transcripts in pterygia. METHODS: RNA was extracted from tissue samples of 33 patients with primary pterygium and 35 volunteers with conjunctiva as the control group. Then the mRNA expression of SDF-1, CXCR4, and CXCR7 was assessed through quantitative Real Time PCR method using appropriate primers. RESULTS: SDF-1 and both receptors transcripts had significantly higher expression in pterygia samples compared to the control group (P < 0.05). The ratio of CXCR7 transcript expression to CXCR4 was 26.4 in patients while it was 11 in controls. CONCLUSION: As SDF-1 and its receptors, CXCR4 and CXCR7, were up-regulated in pterygia, SDF-1/CXCR4/CXCR7 axis may contribute to pterygium formation which can be possibly restrained by down-regulating this signaling pathway.

Surgical outcome of conjunctival rotational autograft-mitomycin C (MMC) versus free conjunctival autograft-MMC for pterygium removal: A randomized clinical trial.

BACKGROUND: Pterygium is a common degenerative eye disease. Despite various surgical methods to treat pterygium, recurrence is the main complication. The main issue is finding a surgical method with the lowest recurrence. OBJECTIVE: to compare the complications, recurrence rate and the cosmetic effects of two surgical techniques, namely conjunctival rotation autograft (CRA) and conjunctival autograft (CA), in treating pterygium. METHODS: This randomized clinical trial was conducted at Khalili Hospital in Shiraz, Iran, from January to August 2015. Forty-five eyes from 45 patients were studied. The patients were randomly divided into two groups using the blocking method. The patients of one group were operated on by the CRA technique, while the other group was operated on by the CA method. The patients were checked for the recurrence of pterygium, and other complications at the end of the first, third, and sixth month. Finally, the data were analyzed using SPSS version 21. RESULTS: The mean age of the patients was 42.5 years. The recurrence of pterygium was not observed in any of the patients 6 months after the surgery. Following 6 months after the operation, graft retraction occurred during the first week for one patient (4.5%) in the CA group, and five patients (21.7%) in the CRA group. The prevalence rate of graft injection among the patients of the CA and CRA groups 6 months after the operation was 9.1% and 65.2%, respectively. There was a significant correlation between injection intensity and the dissatisfaction of the patients with the operation's outcome (p=0.017). CONCLUSION: CRA with mitomycin is considered as an effective method to reduce the recurrence of pterygium after operation. This technique can be used as an acceptable method for pterygium operation, especially for patients with insufficient conjunctiva. CLINICAL TRIAL REGISTRATION: The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT2016092119581N2. FUNDING: The study was financially supported by Shiraz University of Medical Sciences (SUMS) (grants No. 8901).

The Relationship between Anterior Chamber Depth, Axial Length and Intraocular Lens Power among Candidates for Cataract Surgery.

INTRODUCTION: Basic anatomical parameters in ophthalmology are variable in different countries according to ethnic groups, genetics and some environmental factors. The aim of this study was to determine the relationship between axial length (AL), anterior chamber depth (ACD) and intraocular lens power (IOL) in a referral center from eastern Iran among patients who had cataract surgery, in comparison to studies from other regions of the world. METHODS: In a cross-sectional retrospective study from 2011 to 2013, the records of 698 cataract patients referring to Khatam Al Anbia general hospital in Mashhad, Iran were evaluated. We divided patients, based on their AL and ACD, into three separate groups and compared their results. The SPSS software was used for data analysis. The Chi-Square test and the Independent-samples t-test were used to compare qualitative and quantitative data between two groups, respectively. The Kendall and the Pearson product-moment correlation tests were used to assess the relationship between AL and ACD. The linear Regression model was used to obtain a mathematical model to estimate ACD, using AL, age and sex. RESULTS: Among individuals who had normal AL (between 22-24.5mm), there was a positive correlation between AL and ACD (p<0.001, r=0.17), however, among individuals with short (AL<22mm) or long sightedness (AL>24.5mm), no significant correlation was detected. We also found that older people have shorter AL (p=0.001 and r=-0.287). Men have an average longer AL (23.7±2.4mm vs. 22.9±2.1mm; p<0.001) and deeper ACD compared to women (2.93±0.45mm vs. 2.82±0.42mm, p=0.002). CONCLUSION: Our findings were mostly similar to previous literature from other regions of the world and although some anatomical variations may exist regarding ophthalmic anatomy, factors like race and geographical area have little effect on the relationship between ACD, AL and IOL power calculation, furthermore our results support the use of third and fourth generation formulas for IOL power calculation.

Changes in corneal topography and biomechanical properties after collagen cross linking for keratoconus: 1-year results.

PURPOSE: To evaluate changes in corneal topography and biomechanical properties after collagen cross-linking (CXL) for progressive keratoconus. PATIENTS AND METHODS: Collagen cross-linking was performed on 97 eyes. We assessed uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA). Corneal topography indices were evaluated using placido disc topography, scanning slit anterior topography (Orbscan II), and rotating Scheimpflug topography (Pentacam). Specular microscopy and corneal biomechanics were evaluated. RESULTS: A 1-year-follow-up results revealed that UCVA improved from 0.31 to 0.45 and BCVA changed from 0.78 to 0.84 (P < 0.001). The mean of average keratometry value decreased from 49.62 to 47.95 D (P < 0.001). Astigmatism decreased from 4.84 to 4.24 D (P < 0.001). Apex corneal thickness decreased from 458.11 to 444.46 µm. Corneal volume decreased from 56.66 to 55.97 mm(3) (P < 0.001). Posterior best fit sphere increased from 55.50 to 46.03 mm (P = 0.025). Posterior elevation increased from 99.2 to 112.22 µm (P < 0.001). Average progressive index increased from 2.26 to 2.56 (P < 0.001). A nonsignificant decrease was observed in mean endothelial count from 2996 to 2928 cell/mm(2) (P = 0.190). Endothelial coefficient of variation (CV) increased nonsignificantly from 18.26 to 20.29 (P = 0.112). Corneal hysteresis changed from 8.18 to 8.36 (P = 0.552) and corneal resistance factor increased from 6.98 to 7.21 (P = 0.202), so these changes were not significant. CONCLUSION: Visual acuity and K values improved after CXL. In spite of the nonsignificant increase in endothelial cell count and increase in the CV, CLX seems to be a safe treatment for keratoconus. Further studies with larger sample sizes and longer follow-up periods are recommended.

Bacterial keratitis in a tertiary eye centre in Iran: a retrospective study.

PURPOSE: To report the characteristics and laboratory findings of 182 patients with bacterial keratitis diagnosed at Farabi Eye Hospital in Tehran, Iran. MATERIALS AND METHODS: In this retrospective study, data were collected on demographics, risk factors, location, size and depth of the ulcer, height of the hypopyon, uncorrected visual acuity, results of smear and culture tests, and antibiotic sensitivity of cultured bacteria. RESULTS: There were 110 (60.4%) males and 72 (39.6%) females with an average age of 56.0 ± 2.3 years. Ocular trauma (17.6%) and positive history of corneal surgery (14.3%) were major risk factors. The mean age of contact lens users was 22.5 ± 7.7 years. Sixty patients (33%) used topical antibiotics, 21 (11.5%) patients utilized topical steroid, and 26 (14.3%) cases used both topical antibiotic and steroid at presentation. Culture results were, 81 (44.5%) cases were Gram-positive, 63 (34.6%) were Gram-negative, 10 (5.5%) were mixed bacteria and in 28 (15.4%) cases had detected growth. The isolated bacterial species from the corneal ulcers were less resistant to ceftazidime (6%) and amikacin (6%). The majority of patients were treated with medical therapy; however, 81 cases (44.5%) received at least one surgical procedure. CONCLUSION: Among the patients with bacterial corneal ulcers, trauma was the most common risk factor. Over-the-counter antibiotic and steroid were commonly used in the majority of patients. The most common bacteria isolated were Gram-positives, and they were less resistant to ceftazidime and amikacin. Penetrating keratoplasty was the most common surgical procedure in patient who required surgery.

Ultraviolet A/riboflavin collagen cross-linking for treatment of moderate bacterial corneal ulcers.

PURPOSE: To evaluate the therapeutic effect of UV-A/riboflavin collagen cross-linking (CXL) on moderate bacterial corneal ulcers. METHODS: Thirty-two patients with moderate bacterial keratitis were selected. All patients were treated according to the standard medical treatment protocol. The patients were randomly allocated to 2 groups: case and control groups of 16 patients each using a numerical randomization table. The case group received CXL treatment. In the CLX group, corneal epithelium was removed and 0.1% riboflavin drops were applied. Then the corneas were irradiated with UV-A (365 nm) with an irradiance of 3 mW/cm for 30 minutes. The grade of ulcers, size of epithelial defects, and area of infiltrates were recorded on days 1, 7, and 14 of treatment. RESULTS: There was no statistically significant difference between the groups 1 day after the treatment. The mean treatment duration was 17.2 ± 4.1 days in the CXL group and 24.7 ± 5.5 days in the control group. The epithelial defects were smaller in the CXL group at 7 days (P = 0.001) and 14 days (P = 0.001) after the beginning of treatment. The area of infiltrates in CXL group was smaller than the control group at both 7 days (P = 0.001) and 14 days (P < 0.001) after the start of treatment. CONCLUSIONS: Our results support the beneficial effect of CXL in patients with moderate bacterial keratitis. In addition to accelerating epithelialization, this method shortens the course of treatment and may minimize or remove the need for surgery or other serious sequelae, such as corneal perforation.