Outcome of Amniotic Membrane Transplant in Persistent Corneal Epithelial Defects

Purpose: To determine the outcome of amniotic membrane transplant in patients with ocular surface disease. Study Design: Interventional Case series study Place and Duration of Study: Layton Rahmatullah Benevolent Trust Eye Hospital, Korangi 2½, Karachi, from January, 2019 to July 2019. Methods: Patients with an age range of 20–45 years, either gender and who had persistent corneal epithelial defects as a consequence of keratitis, chemical injuries, bullous keratopathy and Mooren’s ulcers were included. Informed consent was obtained. Preserved amniotic membrane was used in all patients and they were followed at 1 week, 1, 3 and finally at 6 months and results were evaluated in terms of stable, healed and pain-free cornea. Results: Mean age of the patients was 37.94 ± 6.78 years. Majority of the patients (60.0%) were less than 40 years of age. Out of 58 patients, 45 (77.6%) were males and 13 (22.4%) were females. Mean duration of injury was 7.67 ± 2.28 weeks with majority of patients i.e. 62% were with less than 8 weeks of duration. Most common cause of persistent corneal epithelial defect was bacterial keratitis (17.2%) followed by vegetative trauma (13.8%). Successful surgical outcome as healed cornea was observed in 53 (91.4%) patients. Conclusion: Amniotic membrane transplant is an effective treatment for persistent corneal epithelial defects unresponsive to standard medical treatment. This surgical technique is effective in terms of healing and resolving the inflammation and preserving the useful vision. Key Words: Persistant corneal epithelial defect, Amniotic Membrane, Bullous keratopathy.

Efficacy of rhNGF-loaded amniotic membrane transplantation for rabbit corneal epithelial and nerve regeneration

AIM: To evaluate the efficacy of recombinant human nerve growth factor-loaded amniotic membrane (rhNGF-AM) on corneal epithelial and nerve regeneration in rabbit model. METHODS: Freshly prepared human amniotic membrane (AM) were immersed into PBS buffer containing 100 or 500 μg/mL rhNGF for 15, 30, and 60min at 4℃. The in vitro release kinetics of rhNGF was measured with ELISA. For in vivo evaluation, the AM were immersed with 500 μg/mL rhNGF for 30min. Fifty-seven rabbits were selected to establish corneal epithelial defect model. In addition to the 19 rabbits in control group, 38 rabbits received AM transplantation with or without rhNGF after the removal of central epithelium. Corneal epithelial defect area, sub-epithelial nerve fiber density, corneal sensitivity, rhNGF contents in resident AM and corneas were measured after the surgery. RESULTS: rhNGF was sustained release from the AM within 14d in vitro, with the positive correlation with initial immersion concentration. The immersion of AM in 500 μg/mL rhNGF for 30min achieved the most stable release within 14d. After transplantation in rabbit cornea, a high concentration of rhNGF in resident rhNGF-AM and cornea was maintained within 8d. Corneal epithelial healing, nerve fiber regeneration and the recovery of corneal sensitivity were significantly accelerated after the rhNGF-AM transplantation when compared to simple AM transplantation (all P<0.05). CONCLUSION: Simple immersion of AM achieves the sustained release of rhNGF, and promotes corneal epithelial wound healing and nerve regeneration, as well as the recovery of corneal sensitivity in rabbit.

Comparative Clinical Analysis of Polymicrobial and Monomicrobial Bacterial Keratitis

Purpose: We comparatively analyzed the microbiological profiles, predisposing factors, clinical aspects, and treatment outcomes of patients with polymicrobial and monomicrobial bacterial keratitis.Methods: A total of 194 cases of culture-proven bacterial keratitis treated between January 2007 and December 2016 were reviewed. Microbiological profiles, the epidemiology, predisposing factors, clinical characteristics, and treatment outcomes were compared between the polymicrobial group (polymicrobial bacterial keratitis [PBK]; 29 eyes, 62 isolates) and monomicrobial (monomicrobial bacterial keratitis [MBK]; 165 eyes, 165 isolates) group.Results: The most common isolates were Enterobacter (24%) in the PBK group and Staphylococcus (22%) in the MBK group. There were no significant differences between the two groups in previous ocular surface disease, previous ocular surgery, prior topical steroid use, epithelial defect size, and hypopyon. Age ≥60 years (PBK vs. MBK, 31% vs. 51%, p = 0.048), symptom duration (4.7 days vs. 8.0 days, p = 0.009), and contact lens use (34% vs. 18%, p = 0.036) were significantly different between the two groups. Regarding treatment outcomes, epithelial healing time ≥10 days, the final best-corrected visual acuity (BCVA), a need for surgical intervention, and the rate of poor clinical outcome were not significantly different between the two groups. Significant risk factors for a poor clinical outcome in all patients were an initial BCVA <0.1 (Z = 6.33, two-proportion Z-test), an epithelial defect size ≥5 mm2 (Z = 4.56), and previous ocular surface disease (Z = 4.36).Conclusions: Polymicrobial bacterial keratitis, compared to monomicrobial bacterial keratitis, was more significantly associated with younger age, contact lens use, and shorter symptom duration.

Severe Keratitis Caused by Acanthamoeba Genotype T12 in Thailand: A Case Report

Acanthamoeba keratitis is predominantly caused by genotype T4. We report a case of severe keratitis caused by Acanthamoeba in a 39-year-old man who had prior accidental exposure to a corrosive chemical. The patient developed central full thickness ring infiltration and epithelial defect with hypopyon that required keratoplasty. The acanthamoebae isolated from the patient exhibited thermotolerance phenotype with the capability to grow well at ambient temperature and at 42°C. Analysis of a near complete 18S rRNA gene of this isolate revealed a distinct sequence that can be unequivocally assigned to genotype T12, a rare genotype incriminated in corneal infections.

Comparison of the efficacy of lotrafilcon B and comfilcon A silicone hydrogel bandage contact lenses after transepithelial photorefractive keratectomy

Background: At completion of transepithelial photorefractive keratectomy (t-PRK) surgery, the eye is usually fitted with a bandage contact lens to reduce discomfort and promote epithelial healing. This study aimed to compare the outcomes of eyes fitted with lotrafilcon B versus comfilcon A, silicone hydrogel bandage contact lenses after t-PRK for the correction of low to moderate myopia, with or without astigmatism. Methods: In this comparative, prospective study, patients with myopia < -6 D with or without astigmatism (< 1.75 D), who underwent t-PRK between January and June 2018, were randomly allocated to the lotrafilcon B and comfilcon A groups. Preoperative characteristics, including age, sex, eye treated, uncorrected visual acuity (UCVA), best-corrected visual acuity, mesopic pupil size, central corneal thickness, and refractive error were recorded. Postoperatively, pain score, UCVA, and corneal epithelial defect size on days 1, 4, and 7 were compared between the two groups. Results: Twenty-nine eyes were included in each group. Demographic characteristics and preoperative measurements were similar between the two groups. UCVA was significantly improved on day 7 as compared to day 1 in the comfilcon A group (P = 0.03), but remained the same in the lotrafilcon B group (P = 0.70) as on day 1 postoperatively. There was no significant difference in UCVA between the two groups at any follow-up visits (all P > 0.05). The pain score on the first postoperative day was significantly higher in the lotrafilcon B-fitted eyes than in the comfilcon A group (P < 0.001), but was significantly reduced in both groups compared to day 1 (both P < 0.001). The epithelial defect in the comfilcon A group was significantly greater than in the lotrafilcon B group (P < 0.001) at day 1 postoperatively, with significant improvement in both groups (both P < 0.001). Conclusions: Healing responses were better with lotrafilcon B than with comfilcon A bandage contact lenses. The patients had a greater mean pain score with lotrafilcon B than with comfilcon A lenses on the first postoperative day, yet the final outcome was comparable between the two groups. We did not encounter any postoperative complications related to contact lens wear. How to cite this article: Lotfy NM, Alasbali T, Alsharif AM, Al-Gehedan SM, Jastaneiah S, Al-Hazaimeh A, Ali H, Khandekar R. Comparison of the efficacy of lotrafilcon B and comfilcon A silicone hydrogel bandage contact lenses after transepithelial photorefractive keratectomy. Med Hypothesis Discov Innov Ophthalmol. 2021 Summer; 10(2): 1-7. https://doi.org/10.51329/mehdiophthal1420

Pattern of Keratitis: A Study of 500 Cases in Tertiary Hospital of Bangladesh

Background: Keratitis is a potentially serious corneal infection and a major cause of visual impairment worldwide. Most common form of which is infectious variety; pathogens may be bacteria, viruses, fungi and parasites which varies with age and predisposing factors. Topical antimicrobials and cycloplegic agents are the mainstay of treatment. Pattern of causative organisms and drug sensitivity changes from time to time and differs from one to another geographic location. Objective: To assess and evaluate the pattern of diagnosed patient of keratitis presented in a tertiary hospital. Material and methods: This cross-sectional study was conducted on 500 diagnosed patients of keratitis in the department of cornea of National Institute of Ophthalmology & Hospital, a well-known tertiary care hospital with 500 beds for a period of 6 months. Patients were selected based on specific selection criteria. Detail history was taken, and thorough ocular examination was done in every patient. Corneal scrapings were taken for Gram’s stain and 10% potassium hydroxide wet mount preparation. All the relevant data was recorded in a predesigned data collection sheet. Results: The mean age of the study subjects was 38.49 years. Male (43.2%) and female (56.8%) ratio was almost equal. The prevalence was highest among lower economic class (56.8%) as usual, and lowest among affluent class (3.8%) but not sparing them. In terms of regional distribution, majority (42.6%) of the patients came from rural area, whereas 37% from urban non-slum area and 20.8% from urban slum area. The problem was mostly observed among day-laborers (24.8%) with gradually declining trend among students (20.6%), housewives (20%), service holders (14.2%), businessmen (3.2%) and unemployed (2.2%), surprisingly! Presentation of the cases were mostly in between 2nd-3rdweek (55%), while 30% patients were presented within 1st week & 15% after 4 weeks of diagnosis. Among the cases, it was found that 28.8% patients had corneal injury, which were caused by vegetative trauma in 16% cases, 4% dust or sand trauma, 2.8% animal injury, 2.2% stick injury, 1% nail injury and 2.8% patients had history of other injury like stone, wooden materials, flying insects, dirty wire etc. Ocular diseases predispose to corneal ulcer were present in 9% patients. These were chronic dacriocistitis, entropion and trichiasis. 1.2% patients were diabetic, and 1% patients had history of inadvertent use of steroids. On the contrary, there were no specific predisposing factors in 71.2% cases. Among the cases, 96.6% experienced photophobia, 90% had foreign body sensation, 88.4% had reduced vision, 85.4% had eye pain, 78.8% suffered from watering, 73.6% had discharge, 48.8% had burning sensation, 12.2% had decreased corneal sensation and 11.2% patients noticed white spot in cornea in first stage. Slit lamp bio-microscopic examination of the patients shows 90% patients had conjunctival injection, 70% had epithelial defect, 28.6% patients had stromal infiltration, 18.4% patients had hypopyon, 14% patients had feathery pattern, 8.8% patients had suppuration, anterior chamber reaction was present in 4.4% cases and 2.2% patients had satellite lesion. The evaluation of etiology on the basis of clinical appearance reveals 61.4% of cases were presented with viral keratitis, 23.0% fungal corneal ulcer, 11.4% with bacterial corneal ulcer, 2.2% with marginal keratitis, 0.8% with exposure keratitis, 0.8% with filamentary keratitis and 0.4% cases with Acanthamoebic keratitis at the time of presentation. While assessing the depth of keratitis of the study subjects, 73.2% found superficial while 26.8% found deep. Assessment of area of corneal involvement in terms of punctate epithelial defect showed that in 46.8 % cases less than 3mm of cornea was involved, 3 to 6 mm of the cornea involved in 19.6 % cases and in 11.8 % corneal involvement was found in more than 6 mm area. Corneal scraping done in 118 (23.6%) out of 500 patients. Among them, Fungi were found in 11.2% cases, mixed organism in 4%, Bacteria in 5.6% and Acanthamoeba found in o.4% cases while 2.4% remains unidentified. Conclusion: Analysis of the study findings shows diversity in the pattern, presentation, predisposing factors of different form of keratitis which may be helpful as basis of further study on this problem.