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.

Delayed Re-epithelialization After Epithelium-Off Crosslinking: Predictors and Impact on Keratoconus Progression

Purpose: To investigate the demographic and corneal factors associated with the occurrence of delayed reepithelialization (DRE) after epithelium-off crosslinking (epi-off CXL).Design:Retrospective case series.Methods:A chart review was performed to identify patients treated with epi-off CXL. DRE was defined as a corneal epithelial defect detected by fluorescein staining that persisted for more than 10 days. Slit-lamp examination, anterior segment optical coherence tomography, corneal topography, and corneal in vivo confocal microscopy (IVCM) were always performed preoperatively and at each follow-up visit (1, 3, 6, 12 months). A generalized estimating equation was used to assess the baseline factors associated with DRE.Results:Data from 153 eyes were analyzed. The mean age of patients was 24.9 ± 8.5 years, and 47 (30.7%) were women. The average reepithelization time was 4.7 ± 1.8 days. Six eyes (3.9%) experienced DRE. In the multivariate model, both the age of the patient (OR = 1.30; p = 0.02) and the corneal steepest meridian (OR = 0.44, p = 0.047) were associated with DRE. Baseline nerve count was also associated with DRE (0.87, p = 0.03). Male gender was associated with a slower early nerve regrowth (1–6 months) (p = 0.048), but not with the occurrence of DRE (p = 0.27). Preoperative central corneal thickness was not related to DRE (p = 0.16). DRE was not associated with keratoconus progression after epi-off CXL (p = 0.520).Conclusions:The association between DRE and age may reflect the age-related decrease in the corneal healing response. Also, low baseline corneal nerve count is associated with DRE. Gender seems to affect reinnervation measured by IVCM but not the reepithelization time. DRE does not seem to affect the efficacy of epi-off CXL.

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

Hypopyon after Primary Cryopreserved Amniotic Membrane Transplantation for Sterile Corneal Ulceration: A Case Report and Review of the Literature

Purpose. To report the acute development of hypopyon after primary cryopreserved amniotic membrane transplantation (AMT) for persistent corneal epithelial defect and sterile ulceration. Case Presentation. A selected case report of a 71-year-old male who underwent primary cryopreserved AMT for the management of long-standing corneal epithelial defects and stroma thinning. The patient developed 2 mm sterile hypopyon within 48 hours after AMT for corneal surface reconstruction. He responded well to the intensified routine postoperative topical treatment of steroid and antibiotic eye drops with the hypopyon resolving completely one week later. Five weeks after surgery, the corneal surface was smooth and epithelialized with no anterior chamber reaction or recurrence of hypopyon. Discussion. Hypopyon may develop as a rare complication of primary cryopreserved AMT for sterile corneal defects. It may be attributed to immunologic or hypersensitivity reaction and should be differentiated from active ocular infection as it resolves spontaneously with the routine postoperative topical treatment of steroid and antibiotic drops.

Comparison of the Effect of Removing Bandage Contact Lens on the Days 3 and 5 Following Photorefractive Keratectomy

AIM: To compare the outcomes of removing bandage contact lens (BCL) on days 3and 5 after photorefractive keratectomy (PRK).Methods: One hundred patients underwent PRK (totally 200 eyes) were enrolled in the present study. The subjects were assigned to two groups. BCL removal was performed in group 1 on the day 3 after PRK from the right eye, but the removal in the group 2 was performed 5 days after the surgery from the left eye. Then, data obtained from both groups were compared. To evaluate complications, the subjects underwent slit-lamp examination in all visits.Results: Filamentary keratitis (FK) was observed in one eye in both groups. The frequency of haze was higherin group 1; however, it was not significant between two group. Using mixed model analysis, significant differences were observed in the rate of complications as well as pain and eye discomfort scores between the groups (P <0.05). No major complication was reported.Conclusion: Majority of post PRK corneal epithelial defect is healed on day 3. However, keeping BCL for 5 days postoperatively, instead of the three days produces slightly lower rate of total complication.

Role of nicergoline in corneal wound healing in diabetic rats

Background To investigate the effect of nicergoline on the rate of complete corneal ulcer reepithelialization (CCUR) in diabetic rats with diabetic keratopathy. Methods Forty-eight streptozotocin-induced diabetic rats were randomly divided into two groups. The experimental group (n = 24) received nicergoline (10 mg.kg− 1.day− 1), while the control group (n = 24) received a placebo. A corneal epithelial defect was induced using a corneal diamond burr, and defect area was compared at time points of 0, 12, 24, 48 and 72 h after the injury using image analysis software. The probability of CCUR within 72 h was assessed using the Kaplan–Meier survival analysis log-rank test. Results When compared, 4 of the 24 rats (17%) in the placebo group and 12 of the 24 rats (50%) in the nicergoline group were found to have CCUR within 72 h (log-rank = 0.027). Cox regression analysis found no effect of the covariates blood glucose (P = 0.601) or weight (P = 0.322) on the corneal reepithelialization (survival) curve. Conclusions Nicergoline increased wound healing rates relative to placebo and may therefore be investigated as a treatment option in diabetic keratopathy.

Subconjunctival Injection of Transdifferentiated Oral Mucosal Epithelial Cells for Limbal Stem Cell Deficiency in Rats

Rat limbal niche cells (LNCs) have been proven to induce transdifferentiation of oral mucosal epithelial cells (OMECs) into corneal epithelial-like cells termed transdifferentiated oral mucosal epithelial cells (T-OMECs). This investigation aimed to evaluate the effect of subconjunctival T-OMEC injections on alkali-induced limbal stem cell deficiency (LSCD) in rats. LNCs were cocultured with OMECs in the Transwell system to obtain T-OMECs, with NIH-3T3 cells serving as a control. Subconjunctival injection of single T-OMEC or OMEC suspension was performed immediately after corneal alkali injury. T-OMECs were prelabeled with the fluorescent dye CM-DiI in vitro and tracked in vivo. Corneal epithelial defect, opacity, and neovascularization were quantitatively analyzed. The degree of corneal epithelial defect (from day 1 onward), opacity (from day 5 onward), and neovascularization (from day 2 onward) was significantly less in the T-OMEC group than in the OMEC group. Cytokeratin 12 (CK12), pigment epithelium–derived factor, and soluble fms-like tyrosine kinase-1 were expressed at a higher rate following T-OMEC injection. Some CM-DiI-labeled cells were found to be coexpressed with CK12, Pax6, and ΔNp63α in the corneal epithelium after subconjunctival injection. Subconjunctival injection of T-OMECs prevents conjunctival invasion and maintains a normal corneal phenotype, which might be a novel strategy in the treatment of LSCD:

Role of Nicergoline in Corneal Wound Healing in Diabetic Rats

Background: To investigate the effect of nicergoline on the rate of complete corneal ulcer reepithelialization (CCUR) in diabetic rats with diabetic keratopathy.Methods: Forty-eight streptozotocin-induced diabetic rats were randomly divided into two groups. The experimental group (n=24) received nicergoline (10 mg.kg-1.day-1), while the control group (n=24) received a placebo. A corneal epithelial defect was induced using a corneal diamond burr, and defect area was compared at timepoints of 0, 12, 24, 48 and 72 hours after the injury using image analysis software. The probability of CCUR within 72 hours was assessed using the Kaplan–Meier survival analysis log-rank test. Results: When compared, 4 of the 24 rats (17%) in the placebo group and 12 of the 24 rats (50%) in the nicergoline group were found to have CCUR within 72 hours (log-rank = 0.027). Cox regression analysis found no effect of the covariates blood glucose (P=0.601) or weight (P=0.322) on the corneal reepithelialization (survival) curve. Conclusions: Nicergoline increased wound healing rates relative to placebo and may therefore be investigated as a treatment option in diabetic keratopathy.