Amniotic Membrane Transplantation Group Research Articles

A COMPARATIVE STUDY TO EVALUATE THE CLINICAL OUTCOME OF CONJUNCTIVAL LIMBAL AUTOGRAFT AND AMNIOTIC MEMBRANE TRANSPLANT FOR THE TREATMENT OF PRIMARY PTERYGIUM

Aim: The aim of the study was to assess the safety and effectiveness of the conjunctival limbal autograft (CLAG) and amniotic membrane transplantation (AMT). Methods: After a full pre-operative assessment 100 patients with primary pterygium attending the ophthalmology outpatient department of a teaching hospital in Eastern India, fulfilling the inclusion and exclusion criteria were selected for our study. The patients were explained the procedure of the study and possible outcomes. They were divided into two groups. Group A: Where 10-0 nylon was to be used for CLAG after pterygium excision. Group B: Where 10-0 nylon was to be used for AMT after pterygium excision. Results: There was marked improvement in vision postoperatively more in the AMT group than CLAG. In the AMT group: 34% had a visual acuity of LogMAR 0.00, 30% had LogMAR 0.12, 12% had LogMAR 0.18, and 24% had LogMAR 0.30 after the surgery. In the CLAG group: 52% had a visual acuity of LogMAR, 20% had LogMAR 0.12, 22% had LogMAR 0.18, and 6% had LogMAR 0.30 after the surgery. Graft and suture-related complications were more in the CLAG group than in the amniotic membrane (AM) graft group. Conclusion: In the present study, The CLAG group was found to be associated with more discomfort, and more post-operative complications than AMT. AM may provide a basement membrane rich in various growth factors and matrix proteins, which promotes epithelial cell migration, adhesion, and differentiation. It is also believed to have anti-inflammatory and antifibrotic effects and exerts anti-scarring effects through the transforming growth factor-β pathway. AMT may be a superior treatment in primary pterygium due to lower recurrence rate, shorter surgical times, and better visual and cosmetic outcomes.

Comparison of the Intrableb Characteristics of Anterior Segment Optical Coherence Tomography Imaging in Trabeculectomy according to Amniotic Membrane Transplantation

Introduction: The purpose of this study was to compare the characteristics of filtering bleb with anterior segment optical coherence tomography (AS-OCT) according to amniotic membrane transplantation (AMT). Methods: One hundred and sixteen eyes of 103 glaucoma patients who underwent trabeculectomy with (AMT group; 85 eyes) or without AMT (control group; 31 eyes) were included. Intrableb parameters were evaluated with AS-OCT. Surgical success was defined as an intraocular pressure (IOP) ≤18 mm Hg and IOP reduction ≥20% without medication at the time of AS-OCT examination. Logistic regression analyses were performed to determine factors associated with IOP control. Results: In the eyes with successful IOP control, the fluid-filled space area, score, and height were greater for the AMT group than the control group (all ps ps ps ≤ 0.041). Lower bleb wall reflectivity alone was associated with surgical success in the control group (OR = 0.815, p = 0.019). Conclusion: The extent of the fluid-filled space was associated with successful IOP control after trabeculectomy with AMT. Hyporeflective bleb wall was associated with successful IOP control in AMT and control groups.

Therapeutic effect of amniotic membrane-fibrin sealant cement on severe ocular surface alkali burn in rabbits

Objective To prepare a biologically active amniotic membrane powder and explore its preservation conditions, and to evaluate the efficacy of the amniotic membrane (AM)-fibrin sealant (FS) cement made from the amniotic powder on the rabbit severe ocular surface alkali burn model. Methods Experimental research. Fresh AM was air-dried, cooled with liquid nitrogen, ground into amniotic powder and sterilized by radiation. The expression of transformed growth factor, nerve growth factor receptor (NGFR), hepatocyte growth factor (HGF), epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) after preparation and 10, 20 and 30 days after storage at room temperature, 4 ℃ and -20 ℃ was tested and compared with that in the fresh AM. The AM-FS cement containing different concentrations of amniotic powder and no amniotic powder was diluted. Rabbit corneal epithelial cells were cultured for 72 hours. The effects of different concentrations of amniotic powder on epithelial cell growth were observed by light microscopy, and the amniotic powder concentration with the largest absorbance value at 450 nm was selected for subsequent animal experiments. Thirty-two right eyes of 32 rabbits as the severe ocular surface alkali burn model were divided using the random counting method into the AM-FS cement group, fresh AM transplantation group, FS group and antibiotic control group (8 rabbits each group) and given different interventions. After weekly observation of corneal repair, hematoxylin and eosin staining, immunohistochemical staining of monocyte chemotaxis protein 1 (MCP-1)and vascular endothelial growth factor (VEGF) were performed and detected by light microscopy at 28 days. The logFC values of the growth factor or receptor expression difference ratio were corrected by BH; the data were analyzed by t-test and analysis of variance. Results: The expression of TGF in the amniotic membrane powder compared with the fresh amniotic membrane group (logFC=-0.11), and the expression of NGFR (HGF, EGF, bFGF) was higher than that of the fresh amniotic membrane group (logFC=-2.07, 0.72, 0.46, 2.62; P<0.05); the expression of HGF, bFGF and EGF in amniotic membrane powder stored for 10 days and 20 days were no lower than fresh amniotic membrane; at 30 days, the expression of growth factors or receptors except HGF and bFGF were decreased, and HGF, bFGF and EGF were no less than 4 ℃ and -20 ℃.The maximum A value was obtained for 0.25 mg/ml of the amniotic membrane powder after 72 hours of the CEC culture 0.98±0.05. The corneal recovery was better in the AM-FS and fresh amniotic membrane transplant groups, with corneal turbidity scores of 3.75±0.46 and 3.50±0.46, respectively, on 28 days, lower than antibiotics (4.29±0.45) (t=2.480, 3.629; P=0.019, 0.001). The corneal neovascular area in the antibiotic control group was compared with the other three groups (t=4.040, 4.339, 2.820; all P<0.001); the corneal neovascular area in the AM-FS group was (9.88±0.20) and (18.96±0.18) mm2 at 7 and 28 days. The corneal neovascularization area at 7 and 28 days in the fresh AM group [(9.54±0.22) and (18.08±0.96) mm2] was smaller than the AM-FS group (t=3.085, 3.017, P=0.005, 0.005). Despite the tiny statistical difference (0.34, 0.88), there was no clinical difference. Hematoxylin and eosin staining showed corneal structures were intact in the AM-FS and fresh AM groups, the epithelial arrangement became normal, and the corneal healing was superior to the FS and antibiotic control groups. Immunohistochemistry showed that the positive expression of VEGF in the fresh AM group was weaker than that in the remaining three groups. MCP-1 was expressed to a similar extent in the AM-FS and fresh AM groups. Conclusions: The active cytokine had high expression and stable properties at room temperature. The AM-FS cement containing 0.25 mg/ml amniotic powder can promote the repair of corneal epithelium, reduce inflammatory reaction and corneal neovascularization after alkali burning in rabbit eyes.

The Effect of Amniotic Membrane Transplantation on Trabeculectomy in Patients with Pseudoexfoliation Glaucoma.

Purpose The aim is to evaluate the effect of amniotic membrane transplantation (AMT) on trabeculectomy with mitomycin C in patients with pseudoexfoliation glaucoma (PXG). Methods This retrospective cohort study included 85 eyes of PXG who underwent trabeculectomy with or without AMT (52/33 eyes in the AMT/control group). Surgical success was defined by these criteria: (1) intraocular pressure (IOP) ≤18 mmHg and IOP reduction ≥20% and (2) IOP ≤15 mmHg and IOP reduction ≥25%. Criteria A and B defined complete success rates as patients who met these criteria without medication, respectively. Criteria C and D defined qualified success rates as patients who met these criteria with medication, respectively. Cumulative probabilities of success were compared using the Kaplan–Meier survival analysis. Cox proportional hazard models were used to evaluate the influence of AMT on surgical success accounting for confounding variables. Results For the AMT group, compared with the control group, the complete success rates at 12 months for criterion A were 86.5% and 63.6%, respectively (P = 0.017) and for criterion B, 86.4% and 63.6% (P = 0.005). The qualified success rates at 12 months for criterion C were 92.1% and 75.1%, respectively (P = 0.047) and for criterion D, 92.1% and 72.1% (P = 0.021). On multivariable Cox regression analyses, AMT was associated with a lower failure rate on criteria A, B, and D (all P ≤ 0.047). Incidence of avascular bleb was higher in the control group than in the AMT group (7 vs 0 eyes; P = 0.004). Conclusions In patients with PXG, trabeculectomy with AMT was associated with higher success rates and a lower incidence of avascular bleb compared with conventional trabeculectomy. Research Registration. This retrospective cohort study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr/cris/index/index.do, KCT0007228).

Membrane of Plasma Rich in Growth Factors in Primary Pterygium Surgery Compared to Amniotic Membrane Transplantation and Conjunctival Autograft

This prospective and comparative study aimed to compare the use of a conjunctival autograft (CAG), plasma rich in growth factors fibrin membrane (mPRGF) or amniotic membrane transplantation (AMT) in primary pterygium surgery. Patients were assigned for surgery with CAG (group A), mPRGF (group B), or AMT (group C). Pterygium recurrence, Best Corrected Visual Acuity (BCVA), graft size (measured with anterior segment optical coherence tomography (AS-OCT)), and ocular surface symptoms (visual analogue scale (VAS) and ocular surface disease index (OSDI)) were evaluated. Thirteen eyes in group A, 26 in group B, and 10 in group C were evaluated. No changes in BCVA (p > 0.05) were found. Recurrence cases for groups A, B, and C were none, two, and two, respectively, and three cases of pyogenic granulomas in group A. The horizontal/vertical graft size was lower in group B vs group A (p < 0.05) from months 1 to 12. The improvement in VAS frequency for groups A, B, and C was: 35.5%, 86.2%, and 39.1%, respectively. The OSDI scale reduction for groups A, B, and C was: 12.7%, 39.0%, and 84.1%. The use of the three surgical techniques as a graft for primary pterygium surgery was safe and effective, showing similar results. The mPRGF graft represents an autologous novel approach for pterygium surgery.

Amniotic Membrane Transplantation for Persistent Epithelial Defects and Ulceration due to Pseudomonas Keratitis in a Rabbit Model.

PurposeThe use of amniotic membrane has been suggested in the treatment of infectious keratitis for its intrinsic anti-infective properties probably mediated by its anti-inflammatory effects. The aim of this study was to investigate the effect of amniotic membrane transplantation (AMT) along with ciprofloxacin to cure the primary stages of Pseudomonas keratitis.MethodsIn total, 28 rabbits were selected and divided in four groups as follows: group 1 as control, group 2 with amniotic membrane, group 3 with ciprofloxacin, and group 4 with amniotic membrane combined with ciprofloxacin. About 0.05 cc suspension of Pseudomonas aeruginosa, 27853 ATCC was injected into corneal stroma.ResultsThe results showed groups of AMT, AMT + ciprofloxacin, and ciprofloxacin had 0% perforation while the control group had 85.6%. Average infiltration of 5.5 mm was observed in ciprofloxacin group, 5 mm in AMT + ciprofloxacin group, 24 mm in AMT group, and finally 23.75 mm for control. Amniotic membrane showed to be effective in prevention of cornea perforation as well as remission of Pseudomonas keratitis. There was no significant difference between ciprofloxacin groups in comparison with ciprofloxacin + AMT group. However, regarding the anti-inflammatory effect, the process of improvement of inflammation in ciprofloxacin + AMT group was faster.Conclusion Transplantation of amniotic membrane in the primary stages of Pseudomonas keratitis treatment remarkably prevents the disease and it can be used to control its process.

Long-term clinical outcome and satisfaction survey in patients with neurotrophic keratopathy after treatment with cenegermin eye drops or amniotic membrane transplantation

PurposeNeurotrophic keratopathy (NK) is a degenerative corneal disease caused by damage of trigeminal innervation. The purpose of this study is to evaluate the clinical outcomes and patient-reported satisfaction of treatment with amniotic membrane transplantation (AMT) or cenegermin eye drops in patients with NK.MethodsClinical charts of patients with NK treated with AMT (group A) or cenegermin eye drops (group B), with at least 12 months of follow-up, were reviewed for demographics, medical history, corneal healing, and disease recurrence. Patient satisfaction was evaluated by a newly developed questionnaire investigating patient’s appreciation of treatment of NK (2 items) and satisfaction with NK treatment outcomes (5 items).ResultsAt the end of treatment, complete corneal healing was observed in 13/15 (86%) patients in group A and in 23/24 (96%) in group B. At 12 months follow-up, 6/13 patients (46%) in group A and 3/23 patients (13%) in group B showed recurrence of NK (p = 0.037).Survival analysis showed that group B remained recurrence free for a significantly longer period of time than the group A (p = 0.028). Patients in group B showed a significantly higher satisfaction when compared with patients in group A (total score: 65.7 ± 15.7 vs 47.4 ± 12.8, p = 0.003), both in terms of patients’ appreciation of treatment (78.3 ± 15.9 vs 52.2 ± 30, p = 0.020) and satisfaction with treatment outcomes (60.7 ± 21 vs 45.4 ± 13.3, p = 0.037).ConclusionsTreatment of NK with cenegermin was associated with long-term maintenance of corneal integrity and a higher degree of patient satisfaction.

Comparing ProKera With Amniotic Membrane Transplantation: Indications, Outcomes, and Costs.

The aim of this study was to compare the outcomes of ProKera versus amniotic membrane transplantation (AMT) in managing ocular surface disease. This study is a retrospective case series of patients who received either ProKera or sutured AMT for ocular surface disease. Patient demographics, treatment indications, retention time, percentage healed area, changes in visual acuity, and costs to the health care system were analyzed. Fourteen patients were identified and analyzed for each group. The main indications for using ProKera and AMT were similar, including corneal ulcer or epithelial defect due to chemical burns, neurotropic state, or herpes zoster keratitis. The average time to dissolution or removal was 24.8 days in the ProKera group, compared with 50.1 days in the AMT group. The average percentage of healed corneal area was 59% for ProKera and 73% for AMT. There was no significant difference between the initial and the final visual acuity within groups and when comparing both groups. In our expense analysis, ProKera had a total cost of 699.00 Canadian dollars (CAD), whereas the cost of suture AMT was 1561.52 CAD. ProKera priced at 11.85 CAD for each percentage healed surface area and at 21.39 CAD for AMT. ProKera allowed for a faster corneal healing than sutured AMT, although its total healed area was less than the latter. Moreover, ProKera is more cost-effective than AMT, thus reducing financial burden to our health care system.

The Effect of a Novel Strategy in Treating Primary Pterygium: A Prospective Randomized Clinical Study

We sought to compare the efficacy and safety of conjunctival autograft (CAG), amniotic membrane transplantation (AMT) with postoperative interferon alfa-2b (IFN alfa-2b), and modified conjunctival autograft plus amniotic membrane transplantation (mCAG plus AMT) with postoperative IFN alfa-2b for primary pterygium. Randomized controlled clinical trial. Eyes with nasal and primary pterygia were randomized in a 1:1:1 ratio to receive CAG, AMT with IFN alfa-2b, or mCAG plus AMT with IFN alfa-2b. Subjects were followed up for 12months. Primary outcomes included recurrence rate and complications. Secondary outcomes included corneal epithelium status, ocular surface symptom score, and visual acuity change. Eighty-five subjects (30 in the CAG group, 25 in the AMT group, and 30 in the CAG+AMT group) completed the 12-month follow-up. No complication or grade 4 recurrence was found. There was no significant difference among the 3 groups in recurrence grade, corneal epithelium status, and visual acuity change. Compared with mCAG+AMT, CAG has a negative effect (β=-0.62, P= .001), and AMT has a negative effect (β=-2.02, P < .001) on postoperative symptom scores. Compared with AMT, CAG has a positive effect (β= 1.28, P < .001) on postoperative symptom scores. All 3 strategies had good safety and clinical efficacy in the study. Compared with conjunctival autograft, the 2 surgeries using no autograft or limited autograft was less traumatic and gave more flexibility for future ocular surface condition changes.

Comparison of amniotic membrane transplantation with and without cultured limbal epithelium for persistent corneal ulcers

This study compared the clinical outcomes of amniotic membrane transplantation with and without cultured limbal epithelium for persistent corneal ulcers. The study included 30 patients that were assigned to either human amniotic membrane transplantation (AMT) only or a two-step cultured limbal epithelial transplant (CLET) with amniotic membrane carrier. The patients underwent a comprehensive ocular examination, Cochet-Bonnet esthesiometry, impression cytology and anterior segment optical coherence tomography (AS-OCT). Slit-lamp images before and after treatment were analyzed using ImageJ to compare the fibrovascular tissue area. The state of epithelialization was assessed by fluorescein staining on day 30. Mean age of patients was 64 ± 20.39 in the AMT group and 55.17 ± 14.51 in the CLET group (p = 0.16). Visual acuity improved significantly in both groups after treatment, but the improvement was significantly greater in the CLET group (p = 0.022). Impression cytology demonstrated PAS + cells in the corneal epithelium in 9 patients from the CLET group and 10 patients in the AMT group (p = 0.704). Cochet-Bonnet esthesiometry increased significantly after treatment with a similar rate between groups (p = 0.435). Improvement with reduction of the fibrovascular tissue area was achieved in both groups (p < 0.01 and p = 0.001 in the CLET and AMT group, respectively). Independent samples T-test demonstrated a greater reduction in the CLET group (p = 0.028). Kaplan-Meier analysis of epithelialization demonstrated higher success rate in the CLET group (p = 0.006). Persistent corneal ulcers could be associated with partial limbal stem cell deficiency (LSCD). In refractory cases, CLET should be the preferred treatment option with more sustainable results regarding corneal epithelialization and stromal scarring.

Effectiveness and Safety of Trabeculectomy along with Amniotic Membrane Transplantation on Glaucoma: A Systematic Review.

Purpose To determine the effectiveness and safety of trabeculectomy along with amniotic membrane transplantation (AMT) for glaucoma. Methods This systematic review was performed using RevMan 5.3. We searched PubMed, EMBASE, and the Cochrane Library and included studies published until September 2019. The treatment group included patients with AMT and trabeculectomy (group A), and the control group had only trabeculectomy (group B). We only included randomized controlled trials. The outcomes were intraocular pressure (IOP), complete success rate, number of antiglaucoma medications, and complications. Results Five studies, including 174 eyes (87 eyes in the AMT group and 87 eyes in the control group), were eligible in this review. The parameters had no significant difference in heterogeneity between the AMT and control groups preoperatively. In the AMT group, the mean IOP was significantly lower at 3 and 12 months after operation (P < 0.0001 and P = 0.02, respectively), while the number of complete successes in the AMT group was significantly higher at 6 and 12 months (P = 0.02 and P = 0.003, respectively) compared with the control group. Complications, including a flat anterior chamber and hyphema, appeared to be decreased in the AMT group compared to the control group (P = 0.02 and P = 0.02, respectively). No differences were observed in the number of antiglaucoma medications, hypotony, encapsulated bleb, or choroidal detachment. Conclusion Compared with only trabeculectomy, it is more efficient and safer to add AMT to trabeculectomy during glaucoma filtering surgery.

Comparative Study on the Efficacy of Frozen Amniotic Membrane Transplantation and Lamellar Keratoplasty in the Treatment of Mooren Ulcer.

To compare of the clinical efficacy of frozen amniotic membrane transplantation (AMT) and lamellar keratoplasty (LKP) in the treatment of Mooren ulcer. Forty patients (42 eyes) with Mooren's ulcer in our hospital from January 2010 to January 2019 were divided into frozen AMT group (20 eyes) and LKP group (22 eyes). Comparative observation of post-operative best corrected visual acuity (BCVA), corneal epithelial healing time, corneal epithelialization time, ulcer healing, corneal transparency, corneal graft transparency, neovascularization and original disease recurrence were observed. The average BCVA at post-operative 6 and 12 months in LKP group were significantly lower than AMT group (P < 0.05). The ulcer healing rates in LKP group (63.6) were significantly higher than AMT group (30) (P < 0.05). The corneal epithelialization time of LKP group were 9.55 ± 1.26 days. The corneal epithelial healing time of AMT group were 13.50 ± 2.21 days. Nine cases were corneal graft transparency grade 0, and 13 cases were grade I. Three eyes in AMT group were corneal transparency grade 0, 7 were grade I and 10 were grade II. Corneal neovascularization were observed in 3 eyes in AMT group and 4 eyes in LKP group. The original disease recurrence rates in LKP group (50) were significantly higher than AMT group (20) (P < 0.05). Four cases of primary corneal transplantation failure were observed in LKP group. Lamellar keratoplasty group obtained significantly better BCVA during follow-up and faster healing time than the frozen AMT group while frozen AMT group had lower original disease recurrence rates than LKP group.

Reconstruction of the ocular surface by autologous transplantation of rabbit adipose tissue-derived stem cells on amniotic membrane.

BackgroundCorneal disease is the second most common cause of blindness in China. Clinically, treatment options for corneal diseases with limbal stem cell deficiency (LSCD) are limited due to a shortage of organ donors and inevitable immune rejection. This study aims to determine the efficacy of reconstructing the ocular surface using autologous cultivated adipose tissue-derived stem cells (ADSCs) and to develop a new clinical treatment for patients with LSCD.MethodsA rabbit LSCD model was first established. Two weeks later, the animals were divided into three groups, including the sham group, the amniotic membrane transplantation group, and the ADSC combined with amniotic membrane transplantation group, and underwent surgery. The efficacy of reconstructing the ocular surface using ADSCs was evaluated using immunofluorescent staining, confocal microscopy (CM) observation, H&E staining, immunohistochemical staining, and scanning transmission electron microscopy observation one, two and four weeks after surgery.ResultsEvaluations of immunofluorescent staining of the cornea pre- and post-surgery yielded significantly lower scores for the corneas in the ADSCs transplantation group than for those in the sham group (F=−7, P=0.002, <0.05) and the amniotic membrane transplantation group (F=−4.67, P=0.018, <0.05) two weeks after surgery. Four weeks after surgery, the corneas of the ADSC combined with amniotic membrane transplantation group were scored significantly lower than those in the sham group (F=−8, P=0.007, <0.05) and the amniotic membrane transplantation group (F=−5.33, P=0.046, <0.05). The data suggest that the use of ADSCs to treat LSCD showed greater efficacy than the other treatment methods. The growth of ADSCs on the corneal surface was examined using confocal and electron microscopes. K3/K12 expression in the corneal epithelium, which was reconstructed by ADSCs, was negative, as shown by immunohistochemical staining.ConclusionsOcular surface reconstruction can be improved by using ADSCs as seed cells and the amniotic membrane as a carrier, thus providing a new therapeutic strategy for patients with LSCD.

A Comparative Study Between Transplantation of Conjunctival Limbal Autograft with Mitomycin C and Amniotic Membrane Transplantation with Mitomycin C in Recurrent Pterygium

Introduction : Pterygium, a wing‐shaped encroachment of the cornea by the conjunctiva, Conjunctival limbal autograft with stem cell (CLAU) or amniotic membrane transplantation (AMT) has been widely adopted in the management of pterygium.Purpose: To compare the efficacy and the complications of conjunctival limbal autograft (CLAU) with mitomycin C 0.2 % and amniotic membrane transplantation (AMT) with mitomycin C 0.2 % for treatment of recurrent pterygiumSubject and methods:80 eyes of 60 patients clinically diagnosed with recurrent pterygium were divided into two groups , group A included 40 eyes underwent pterygium excision and MMC 0.2% with CLAU , group B included 40 eyes underwent pterygium excision and MMC 0.2% with AMT . Recurrence was defined as fibrovascular tissue extension of more than one mm onto the cornea in the area of previously excised pterygium. Mean follow up period 8±1 month . Recurrence was compared in each group by using ӽ2 testResults:No major postoperative complications occurred during 6-9 months of follow-up . In CLAU group (A)only 5 eyes of recurrence occur(12.5%)after 7 months of follow up . Recurrence occur in 12 eyes (30%)in AMT group (B) after 6 months ( P value =0.043, ӽ2 test).The operated site was look like the normal adjacent site in 77%of the non recurrence group A versus 10% in group BConclusion: CLAU with MMC is more effective than AMT with MMC for treatment of recurrent pterygium and the final cosmetic appearance is more acceptable in CLAU group than AMT group B .

A Retrospective Study to Compare the Recurrence Rate After Treatment of Pterygium by Conjunctival Autograft, Primary Closure, and Amniotic Membrane Transplantation.

BackgroundThis study aimed to investigate the effectiveness of conjunctival autograft compared with primary closure and amniotic membrane transplantation for primary pterygium excision.Material/MethodsData were retrospectively studied from all primary pterygium excisions from January 2002 to December 2017 from the electronic database at the University Eye Hospital, Tübingen.ResultsFrom 521 primary pterygium excisions, 284 (54.5%) were primary closures, 203 (39.0%) were conjunctival autografts, and 34 (6.5%) were amniotic membrane transplants. The mean number of primary pterygium excisions was 33 per year (range, 14–56 per year). The mean patient age was 58±15 years. Younger age was associated with a significantly increased recurrence rate (P=0.002). The mean pterygium recurrence rate in the three study groups at 12 months after surgery was 11.3% (range, 6.4–14.7%). Recurrence occurred 13 patients (6.4%) in the conjunctival autograft group, 41 patients (14.4%) in the primary closure group, and five patients (14.7%) in the amniotic membrane transplantation group. Conjunctival autograft was associated with a significantly lower recurrence rate (P=0.005).ConclusionsA retrospective study at a single center to compare conjunctival autograft with primary closure and amniotic membrane transplantation for primary pterygium excision showed a significantly lower recurrence rate after surgery using a conjunctival autograft.

Scleral Ischemia in Acute Ocular Chemical Injury: Long-Term Impact on Rehabilitation With Limbal Stem Cell Therapy

This study describes the impact of scleral ischemia on globe survival in cases of acute chemical injury and the outcome of limbal stem cell transplant in these eyes. This is a single-center, retrospective case study that reviews outcomes in all patients with acute chemical injury of grades IV and above who presented within 6 weeks from injury. The period of the study is between May 2012 and May 2017. Eyes presenting without scleral ischemia underwent amniotic membrane transplantation (group A), whereas eyes presenting with scleral ischemia underwent tenonplasty with amniotic membrane transplantation (group B). Simple limbal epithelial transplantation (SLET) was performed at 6 months in all consenting patients from both these groups. The primary outcome was defined as globe preservation at 3 months, whereas the secondary outcome was defined as SLET success at 1 year. Twenty-three eyes of the 23 patients were included in our study. Of the 13 eyes in group B, 2 eyes developed phthisis and 2 eyes developed hypotony. None of the 10 eyes in group A developed hypotony or phthisis. The eyes that developed into hypotony and phthisis had presented with more extensive scleral ischemia (>180 degrees). In group B, 5 of 7 patients failed SLET. This was high compared with group A in which 2 of 8 patients failed SLET. The presence and extent of scleral ischemia are important prognostic factors when assessing recovery in eyes with acute chemical injury. The authors recommend that it be added as a poor prognostic indicator in the existing classifications of acute chemical injury.

Amniotic membrane transplantation with or without autologous cultivated limbal stem cell transplantation for the management of partial limbal stem cell deficiency.

PurposeTo compare the outcomes of amniotic membrane transplantation (AMT) vs cultivated limbal stem cell transplantation (LSCT) in eyes with partial limbal stem cell deficiency (LSCD) following chemical burns.MethodsEyes with unilateral partial LSCD (#180° involvement) were randomized in two groups to undergo either pannus resection combined with AMT or pannus resection combined with LSCT in a tertiary eye care hospital. Primary outcome measures were time to corneal epithelialization and absence of conjunctivalization of the cornea. Patients were followed up at 1 week, 1, 3, 6, and 12 months after the surgical procedure.ResultsThere was no difference between mean age (30.85±5.8 vs 28.64±6.4 years, P=0.40) and sex distribution of patients between the two groups at baseline. Mean time to corneal epithelialization was 10.45±5.8 days in the AMT group and 11±3.9 days in the LSCT group (P=0.43). At the end of 1 year, there was no significant difference between the degree of conjunctivalization of cornea, (P=0.06) corneal vascularization, (P=0.08), and clarity (P=0.07) in both groups.ConclusionOur study showed that AMT alone is a useful therapeutic modality in cases with partial LSCD due to ocular chemical injury. Stem cell transplantation may not be required in these cases.

Comparison of free conjunctival autograft versus amniotic membrane transplantation for pterygium surgery

PurposeTo compare the recurrence rate and surgical outcomes of amniotic membrane transplantation (AMT) and free conjunctival autograft (CAT) for pterygium surgery. MethodsIn this prospective study, 60 patients with primary pterygium were randomly assigned to two groups of CAT or AMT and were compared in terms of recurrence rate, mean healing time of corneal epithelial defects, the mean level of inflammation, and complications. ResultsThe mean ± SD age of patients was 48.98 ± 9.8 years (range, 27–71 years). 73.3% were men, and 26.7% were women. The groups did not differ with respect to demographic characteristics (P > 0.05). Patients were followed for an average of 12.6 ± 1.3 months. The recurrence rates were 6.7% and 3.3% in the AMT and CAT groups, respectively (P > 0.05). Comparison of mean inflammation score showed higher inflammation in the AMT group in the first, third, and sixth postoperative month (P < 0.05). Mean healing times of corneal epithelial defects were 2.5 ± 0.572 and 2.67 ± 0.479 days in the CAT and AMT groups, respectively (P = 0.173). ConclusionsNo significant complication was observed during or after both surgical methods. No statistically significant difference was seen in visual acuity changes and epithelial healing in CAT and AMT groups, but more inflammation and recurrence rate were seen in AMT group.

Clinical observation on limbal stem cell transplantation and amniotic membrane transplantation for the treatment of pterygium

Objective To observe the clinical effect of amniotic membrane transplantation and autologous corneal limbal stem cell transplantation in the treatment of primary pterygium. Methods Seventy-five eyes of 68 cases of pterygium were randomly divided into two groups: the stem cell transplantation groups, 38 eyes of 35 cases, underwent pterygium excision combined with autologous limbal stem cell transplantation; amniotic membrane transplantation group, 37 eyes of 33 cases, underwent pterygium excision combined with amniotic membrane transplantation. The postoperative recurrence, corneal wound healing time and complications of two groups were observed. Results The recurrence rate of stem cell transplantation group was 2.6%, the recurrence rate of amniotic membrane transplantation group was 18.9%, and the recurrence rate of stem cell transplantation group was lower than that of amniotic membrane transplantation group. In the stem cell transplantation group, corneal wound healing time was average (3.49±0.50) days, the average time of corneal wound healing time was (5.28±1.37) days. The corneal wound healing time of the stem cell transplantation group was shorter than that of the amniotic membrane transplantation group, the difference was statistically significant (t=7.550, P=0.000). Conclusion The effect of autologous corneal limbal stem cell transplantation for primary pterygium, with shorter healing time, lower recurrence rate and fewer complications, is better than that of amniotic membrane transplantation. Key words: Pterygium; Transplantation; Stem cell; Amniotic membrane

Surgical outcomes of perforated and unperforated corneal descemetocele.

To compare the surgical outcomes of amniotic membrane transplantation (AMT) and penetrating keratoplasty (PK) in perforated and non-perforated corneal descemetocele. In this study, we retrospectively examined 48 eyes of 48 patients operated with AMT, and 32 eyes of 32 patients operated with PK for perforated and non-perforated descemetocele. There were no significant differences between the two groups with regard to age, sex, laterality, follow-up duration, cause of descemetocele, and localization (p>0.05). Thirty-six (75%) eyes in the AMT group and 17 (53.1%) eyes in the PK group were perforated prior to operation (p=0.043). Surgical success was achieved in 35 (73%) of 48 eyes underwent AMT and 28 (87.5%) of 32 eyes underwent PK (p=0.118). Perforation size was the only parameter significantly affecting surgical success (AMT p=0.001, PK p=0.003). The visual acuity was significantly better at the postsurgical period compared to the presurgical period in both groups (p=0.003, p<0.001). It was observed that the postsurgical change in the visual acuity score was significantly greater in the PK group (p=0.001). Penetrating keratoplasty is superior to AMT for achieving ocular surface integrity and enhancing visual acuity. Amniotic membrane transplantation saves time for patients and surgeons when donor cornea supply is limited and it allows PK to be performed at a quiet period when inflammation is suppressed.