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.

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.

Five Years Pathological Evaluation of Corneal Regrafts: A Study from Southern Iran.

PURPOSE: Corneal regrafts sometimes needed to restore the transparency after graft failure. The aim of the study is five years epidemiologic and histopathological evaluation of corneal regrafts. METHODS: In this cross-sectional study, all corneal regrafts during 5 years (2012-2016) were assessed in the Khalili Ophthalmology Center at Shiraz city. Demographic data including age, area of residence, primary disease, type of graft, cause of regraft, interval between primary and subsequent grafts (IPSG), associated eye diseases or surgeries, and systemic diseases were recorded. Also, microscopic findings of corneas were reviewed. RESULTS: Among a total of 1190 corneal grafts, 76 of them (6.38%) were regrafts. The most common type of grafting was penetrating keratoplasty (PK). The shortest IPSG was observed in fungal keratitis. Main causes of graft failure were endothelial dysfunction, infection, immunologic rejection, technical problems, and recurrence of primary disease, respectively. The most common histopathological finding in failed grafts was severe endothelial cell loss (89.8%). Also, more than half and one-third of cases had Descemet membrane changes and stromal ingrowth, respectively. CONCLUSION: Endothelial cell loss was the major cause of failure in our study. Also, recurrence rate in infective cases, especially fungal keratitis, was very high. Considerable presence of histopathological changes such as doubling of Descemet membrane and retrocorneal fibrous ingrowth need further investigations. Perhaps, modification in techniques of corneal grafting and assessment of donor tissue and recipient bed along with any need for longer medical treatment are the basis for future studies in order to increase graft survival.

Outcomes of photorefractive keratectomy in patients with atypical topography.

BACKGROUND: Photorefractive keratectomy (PRK) is at risk of serious complications such as corneal ectasia, which can reduce corrected distance visual acuity. The rate of complications of PRK is higher in patients with atypical topography. OBJECTIVE: To determine the outcomes of photorefractive keratectomy in patients with atypical topography. METHODS: This cross-sectional study was done in 2015 in Shiraz in Iran. We included 85 eyes in this study. The samples were selected using a simple random sampling method. All patients were under evaluation for uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction, corneal topography, central corneal thickness using pentacam, slit-lamp microscopy, and detailed fondus evaluation. The postoperative examination was done 1-7 years after surgery. Data were analyzed using IBM SPSS 21.0 version. To analyze the data, descriptive statistics (frequency, percentage, mean, and standard deviation), chi-square, and independent samples t-test were used. RESULTS: We studied 85 eyes. Among the patients, 23 (27.1%) were male and 62 (72.9%) were female. Mean age of the participants was 28.25±5.55 years. Mean postoperative refraction was - 0.37±0.55 diopters. Keratoconus or corneal ectasia was not reported in any patient in this study. There was no statistically significant difference between SI index before and after operation (p=0.736). Mean preoperative refraction was -3.84 ± 1.46 diopters in males and -4.20±1.96 diopters in females; thus there was not statistically significant difference (p = 0.435). CONCLUSION: PRK is a safe and efficient photorefractive surgery and is associated with low complication rate in patients with atypical topography.

Correlation Between Intraocular Pressure and Central Corneal Thickness in Persian Children.

INTRODUCTION: This study aimed to determine intraocular pressure (IOP) and central corneal thickness (CCT) measurements in healthy Persian children to find clinical reference values in this ethnicity. Additionally, we examined the possible relationship between these measurements. METHODS: This cross-sectional study included 262 eyes of 131 Persian primary school children between 6 and 13 years of age. All eyes were healthy and had no anterior or posterior segment abnormalities, corneal disease, or evidence of glaucoma. Specular microscopy was used to measure CCT and both noncontact tonometry (NCT) and Goldmann applanation tonometer (GAT) were used to measure IOP. Correlations between IOP measurements were also examined. RESULTS: Mean CCT was 513.47 ± 34.51 µm in the right eye (OD) and 513.93 ± 33.88 µm in the left eye (OS). The CCT was not significantly different between older (10-13 years) and younger (6-9 years) patients. Mean IOP measured with GAT was 13.86 ± 2.13 mmHg OD and 13.72 ± 2.04 mmHg OS and mean IOP measured with NCT was 15.26 ± 2.38 mmHg OD and 15.11 ± 2.18 mmHg OS. The IOP and CCT measured with GAT were weakly correlated (OD: r = 0.141, P = 0.114; OS: r = 0.236, P = 0.007). However, IOP and CCT measured with NCT (OD: r = 0.487, P = 0.000; OS: r = 0.456, P = 0.000) were moderately correlated. Our outcomes demonstrated that for 100 µm increase in CCT, IOP measured with GAT and NCT increased by 0.8 and 3.3 mmHg, respectively, in OD and by 1.4 and 2.9 mmHg in OS. Based on intraclass correlation coefficients, IOP measurements made with GAT and NCT were in fair agreement in OD and in good agreement in OS. CONCLUSION: The IOP and CCT in healthy Persian school children (6-13 years old) were positively correlated. Our findings revealed that corneal thickness is thinner in Persian children than in most other racial groups. FUNDING: This study has been funded by deputy dean in research of School of Medicine and deputy vice chancellor of Shiraz University of Medical Sciences, Shiraz, Iran.

Limbal Stem Cell Transplantation for Gelatinous Drop-like Corneal Dystrophy.

PURPOSE: To report the outcomes of allograft limbal stem cell transplantation for recurrent gelatinous drop-like corneal dystrophy (GDLD). METHODS: In this non-comparative interventional case series, 4 eyes of 3 consecutive patients with recurrent GDLD underwent allograft limbal stem cell transplantation. Two eyes underwent concomitant penetrating keratoplasty while the other two underwent simultaneous superficial keratectomy. Main outcome measures were best spectacle corrected visual acuity, intraocular pressure and corneal clarity. RESULTS: Patient age ranged from 28 to 63 years. Mean follow-up after surgery was 23±10 (median, 22; range, 12-36) months. Mean visual acuity improved from 2.70±0.61 logMAR preoperatively to 1.05±0.06 logMAR at final postoperative visit (P=0.066). Intraocular pressure was normal in all eyes at baseline and remained within normal limits at all postoperative visits. All corneas remained smooth and clear during the follow-up period with no episode of rejection or recurrence. All patients maintained ambulatory vision until final follow-up. CONCLUSION: The present study provides further evidence that limbal stem cell transplantation may be an effective therapeutic alternative in patients with GDLD.

Mycobacterium aurum keratitis: an unusual etiology of a sight-threatening infection.

Atypical fast-growing Mycobacterium species are usually identified after laser-assisted in situ keratomileusis, cosmetic surgeries, and catheter-related, pulmonary or soft tissue infections. We herein present the case of a 56-year-old man with purulent discharge, redness, and foreign body sensation in his left eye. He underwent two surgeries that partially controlled the infection but were not curative. Corneal transplantation was performed, and a biopsy of the excised cornea indicated Mycobacterium aurum infection, which was confirmed by polymerase chain reaction-restriction fragment length polymorphism analysis. This appears to be the first documented case of keratitis attributable to the non-tuberculous mycobateria M. aurum. The intractable extra-ocular progression of the disease in the absence of general signs or symptoms was notable. We suggest considering non-tuberculous mycobacteria among the probable causes of complicated keratitis or keratitis that does not respond to drug treatment, especially in regions where tuberculosis is endemic.

Mycobacterium aurum keratitis: an unusual etiology of a sight-threatening infection

Atypical fast-growing Mycobacterium species are usually identified after laser-assisted in situ keratomileusis, cosmetic surgeries, and catheter-related, pulmonary or soft tissue infections. We herein present the case of a 56-year-old man with purulent discharge, redness, and foreign body sensation in his left eye. He underwent two surgeries that partially controlled the infection but were not curative. Corneal transplantation was performed, and a biopsy of the excised cornea indicated Mycobacterium aurum infection, which was confirmed by polymerase chain reaction-restriction fragment length polymorphism analysis. This appears to be the first documented case of keratitis attributable to the non-tuberculous mycobateria M. aurum. The intractable extra-ocular progression of the disease in the absence of general signs or symptoms was notable. We suggest considering non-tuberculous mycobacteria among the probable causes of complicated keratitis or keratitis that does not respond to drug treatment, especially in regions where tuberculosis is endemic.