Pinnita Prabhasawat

Amniotic membrane transplantation for acute chemical or thermal burns

PURPOSE To determine whether preserved human amniotic membrane (AM) can be used to treat ocular burns in the acute stage. DESIGN Prospective, noncomparative, interventional case series. PARTICIPANTS Thirteen eyes from 11 patients with acute burns, 10 eyes with chemical burns and 3 with thermal burns of grades II-III (7 eyes) and grade IV (6 eyes), treated at 7 different facilities. METHODS Patients received amniotic membrane transplantation (AMT) within 2 weeks after the injury. MAIN OUTCOME MEASURES Integrity of ocular surface epithelium and visual acuity during 9 months of follow-up. RESULTS Ten patients were male and one patient was female; most were young (38.2 +/- 10.6 years). For a follow-up of 8.8 + 4.7 months, 11 of 13 eyes (84.63%) showed epithelialization within 2 to 5 weeks (23.7 +/- 9.8 days), and final visual acuity improved > or = 6 lines (6 eyes), 4 to 5 lines (2 eyes), and 1 to 3 lines (2 eyes); only one eye experienced a symblepharon. Eyes with burns of grade II to III showed more visual improvement (7.3 +/- 3 lines) than those with burns of grade IV (2.3 +/- 3.0 lines; P < 0.05, unpaired t test). In the group with grade II or III burns, none had limbal stem cell deficiency. All eyes in the group with grade IV burns did experience limbal stem cell deficiency. CONCLUSIONS Amniotic membrane transplantation is effective in promoting re-epithelialization and reducing inflammation, thus preventing scarring sequelae in the late stage. In mild to moderate burns, AMT alone rapidly restores both corneal and conjunctival surfaces. In severe burns, however, it restores the conjunctival ocular surface without debilitating symblepharon and reduces limbal stromal inflammation, but does not prevent limbal stem cell deficiency, which requires further limbal stem cell transplantation. These results underscore the importance of immediate intervention in the acute stage of eyes with severely damaged ocular surface. Further prospective randomized studies including a control group are required to determine the effectiveness of AMT in acute chemical and thermal burns of the eye.

Amniotic membrane grafts for nontraumatic corneal perforations, descemetoceles, and deep ulcers☆

PURPOSE To describe the clinical outcome of amniotic membrane transplantation (AMT) for nontraumatic corneal perforations, descemetoceles, and deep ulcers. DESIGN Retrospective, noncomparative, interventional case series. PARTICIPANTS Thirty-four eyes of 33 consecutive patients operated on for nontraumatic corneal perforations or descemetoceles at four academic departments of ophthalmology. Associated autoimmune disorders included rheumatoid arthritis (n = 6), Stevens-Johnson syndrome (n = 3), ocular cicatricial pemphigoid (n = 2), systemic lupus erythematosus (n = 1), and one eye with Moorens ulcer, as well as neurotrophic, or exposure keratopathy (n = 10), postinfectious nonhealing ulcers (n = 6), and postsurgery (n = 5). INTERVENTION Three or four layers of amniotic membrane (AM) were applied over the ulcer bed and anchored with 10-0 nylon interrupted or running sutures. A large AM piece was used as a patch to cover the entire corneal surface. MAIN OUTCOME MEASURES Formation of anterior chamber depth, epithelialization of the AM grafts, and stability of the corneal stromal thickness. RESULTS The mean follow-up period was 8.1 +/- 5.7 (ranging from 2-23) months. A successful result was observed in 28 of 34 eyes (82.3%). Of the successful cases, 23 eyes needed one AMT procedure, whereas 5 eyes needed two procedures to achieve a successful result. In five eyes, a subsequent definitive surgical procedure such as penetrating keratoplasty or lid surgery was needed. Failure was observed in six eyes with rheumatoid arthritis, neurotrophic keratopathy, or graft melting. CONCLUSIONS AMT is an effective method for managing nontraumatic corneal perforations and descemetoceles. It can serve as either a permanent therapy or as a temporizing measure until the inflammation has subsided and a definitive reconstructive procedure can be performed. This treatment option is also beneficial in those countries where corneal tissue availability is limited.

Frequent association of delayed tear clearance in ocular irritation

AIM To explore the pathogenic role of delayed tear clearance. METHODS By comparing 10 patients with punctal obstruction and 20 asymptomatic normals, delayed tear clearance was diagnosed in 70 patients without apparent punctal obstruction using fluorescein clearance test. RESULTS The majority were older (71.4 (SD 1.2) years) and women (66%). Frequent complaints included redness, itching, mucus discharge, and crusting, which tended to be worse upon awakening. Common associated problems were medicamentosa (13%), drug induced pseudo pemphigoid, ocular hypertension (27%), and glaucoma (7%). Topical non-preserved 1% methylprednisolone resulted in subjective (83%) and objective (80%) improvement and resolution of delayed tear clearance (87%). CONCLUSION These results indicate strong association of delayed tear clearance with intrinsically and extrinsically generated ocular surface inflammation. The presence of delayed tear clearance may set up a vicious cycle to aggravate the existing inflammation. Future prospective studies are needed to delineate the pathogenic role of delayed tear clearance in various ocular surface disorders.

Single and multilayer amniotic membrane transplantation for persistent corneal epithelial defect with and without stromal thinning and perforation

AIMS To evaluate the efficacy of amniotic membrane transplantation (AMT) in persistent corneal epithelial defect with or without stromal thinning and corneal perforation. METHODS 28 patients (28 eyes) with persistent corneal epithelial defect unresponsive to medical treatment were given preserved human amniotic membrane transplants. The patients were divided into three groups: group A, persistent corneal epithelial defect 10 eyes; group B, epithelial defect with stromal thinning 13 eyes; and group C, corneal perforation five eyes. AMT was performed using one layer in group A and multilayers in group B and C. The causes of persistent epithelial defect were neurotrophic keratopathy (24 eyes), limbal deficiency (six eyes), exposure keratopathy (four eyes), and Moorens ulcer (one eye). RESULTS Success was noted in 82.1% (23/28 eyes) in all groups, with 80% (8/10 eyes), 84.6% (11/13 eyes), and 80% (4/5 eyes) in groups A, B, and C respectively, with a mean follow up of 10.9 months (1–30 months). The mean epithelialisation time after AMT was 2.1 weeks. The healing times of groups B and C are also significantly shorter than group A (p=0.017 and 0.018, respectively). Corneal stromal thickness was significantly increased in all cases in groups B and C (p=0.006). Those with corneal perforation in group C were completely healed by multilayer AMT. There was no difference in the epithelialisation time between successful cases treated by a single operation (17 eyes) or repeated operation (six eyes). Vision improved in 18.9% (8/28 eyes) and worsened as a result of cataract formation in 2.3% (1/28 eyes). Failure was noted in 17.9% (5/28 eyes), because of corneal infection (two eyes), neurotrophic keratopathy with and without limbal deficiency (two eyes), and intractable corneal perforation (one eye). No patient developed major immediate postoperative complications or graft rejection. CONCLUSION Amniotic membrane can successfully treat refractory corneal epithelial defect by promoting epithelial healing and thus prevent corneal perforation. It can be used as a treatment for corneal perforation by restoring corneal stromal thickness so that emergency penetrating keratoplasty can be avoided.

Amniotic membrane transplantation for reconstruction after excision of large ocular surface neoplasias

Aim: To evaluate the clinical outcome of patients in whom ocular surface reconstruction was performed using amniotic membrane transplantation (AMT) after the excision of large (>20 mm square) ocular surface neoplasias (OSN). Methods: A non-comparative interventional case series. In 16 eyes of 16 patients, excision of large OSN including conjunctival intraepithelial neoplasia (CIN), primary acquired melanosis, and malignant melanoma was followed by adjunctive cryotherapy and suturing of a single layer of amniotic membrane (AM) with the basement membrane side facing up to the healthy bordering tissue. Epithelial healing, complications, and tumour recurrences were analysed. Results: During a mean follow up of 23.7 (SD 11, range 11–43) months, ocular surface healing was rapid and complete in all cases. One complication of pyogenic granuloma was noted. Tumour recurrence occurred in one out of 10 CIN cases (10%), no recurrences were observed in the patients with melanotic lesions. Conclusions: AMT in lieu of conjunctival or mucosal autograft is an effective substrate for reconstructing the ocular surface following excision of large OSN. AMT is effective in managing large OSN by avoiding the complications that may be associated with conventional removal, specifically in cases where the limbal architecture is destroyed by surgical resection or adjuvant therapies.

Amniotic membrane transplantation after the primary surgical management of band keratopathy.

Purpose. To determine the safety and efficacy of amniotic membrane transplantation to restore and maintain a stable corneal epithelium and reduce ocular surface pain after surgical removal of band keratopathy arising from ocular causes. Methods. Fifteen patients (16 eyes) from two centers with band keratopathy secondary to ocular causes underwent amniotic membrane transplantation as a graft after surgical removal of calcific deposits with or without the use of ethylenediaminetetraacetic acid. In a prospective, consecutive, uncontrolled case series, the rate of corneal epithelialization and resultant surface stability were recorded over a mean follow-up period of 14.6 months. Results. Pain from ocular surface instability was the presenting complaint in 14 of 15 (93.3%) patients and resolved in all cases after the procedure even for those who experienced a recurrence of the calcific deposit. Fifteen of 16 eyes (93.7%) achieved epithelialization with a mean time to epithelial healing of 15.2 days. The only eye that failed to heal was subsequently diagnosed with total limbal stem cell deficiency. Visual acuity improved in five of nine (44%) sighted eyes and remained unchanged in four of nine (56%). No patient experienced any major surgical or medical complication after the procedure. Conclusion. Amniotic membrane transplantation represents a safe and effective method to restore a stable corneal epithelium in eyes after primary surgical removal of band keratopathy arising from ocular causes.

Topical 0.002% Mitomycin C for the Treatment of Conjunctival-corneal Intraepithelial Neoplasia and Squamous Cell Carcinoma

PURPOSE To demonstrate the efficacy of topical 0.002% mitomycin C (MMC) as an adjunctive and alternative treatment in primary and recurrent conjunctival-corneal intraepithelial neoplasia (CCIN) and squamous cell carcinoma (SCC). METHODS The medical records of 7 patients with histopathologically confirmed CCIN and conjunctival SCC were retrospectively reviewed. All cases were treated with topical 0.002% MMC 4 times daily. The tumor size pre- and post-treatment, clinical response, and ocular complications were evaluated. RESULTS The mean age of the patients was 56 +/- 13.4 years. The most common presenting symptom was foreign body sensation (57.1%) with a mean duration of 2.3 +/- 3.8 months. Six patients had pathologically proven CCIN (85.7%) and 1 had SCC (14.3%). Before MMC treatment, 6 eyes (85.7%) had recurrences after surgical excision. The tumor-free period ranged from 2 to 19 months. Two patients had multiple recurrences. MMC 0.002% 4 times daily was applied for a period of 5.4 +/- 4.4 weeks (range, 2-14). All had complete tumor regression as observed clinically and confirmed by impression cytology. Side effects of MMC therapy included ocular irritation, mild conjunctival hyperemia, and punctate keratopathy. There were no serious complications detected. The mean follow-up time was 30.7 +/- 15 months (range, 2-52) with no evidence of clinical recurrence in any case. CONCLUSIONS Topical 0.002% MMC showed a favorable outcome as an adjunctive and alternative treatment of CCIN and SCC with regression of primary and recurrent tumors.

Performance profile of sodium hyaluronate in patients with lipid tear deficiency: randomised, double‐blind, controlled, exploratory study

Aim: To assess the short-term efficacy of hypotonic 0.18% sodium hyaluronate in patients with evaporative tear-sufficient dry eye due to lipid tear deficiency (LTD). Methods: This was a randomised, double-blind, controlled, exploratory study. A total of 10 patients with dry eye due to LTD were treated as follows: one drop of hypotonic 0.18% sodium hyaluronate in one eye and one drop of isotonic 0.3% hydroxypropyl-methylcellulose (HPMC)/0.1% dextran in the other eye. Non-invasive tear film break-up time (NIBUT) evaluated by using a tear scope with grid pattern and subjective ocular symptoms of dry eye were assessed at 15, 30, 60 and 90 min after instillation. Results: Both sodium hyaluronate and HPMC/dextran caused a significant (p<0.05) improvement in NIBUT and symptoms. Mean (SD) NIBUT in the sodium hyaluronate group was 3.2 (1.0), 6.4 (2.8), 5.5 (1.9), 5.3 (1.3) and 3.9 (1.7) s at 0, 15, 30, 60 and 90 min, respectively, compared with 3.6 (1.9), 5.5 (3.2), 5.0 (1.5), 4.4 (2.2) and 3.5 (1.2) s in the HPMC/dextran group. However, increase in NIBUT was significantly (p<0.05) greater and longer in the sodium hyaluronate group than in the HPMC/dextran group. Conclusion: Treatment with sodium hyaluronate and HPMC/dextran eye drops is useful for treating patients with dry eye due to LTD. However, sodium hyaluronate caused a significantly (p<0.05) greater increase in NIBUT values than HPMC/dextran in such patients.

A randomized double-masked study of 0.05% cyclosporine ophthalmic emulsion in the treatment of meibomian gland dysfunction.

Purpose: To compare the efficacy of topical cyclosporine [0.05% cyclosporine A (CsA)] and preservative-free artificial tears in the treatment of meibomian gland dysfunction (MGD). Methods: A 3-month prospective, randomized, double-masked, parallel-group controlled trial enrolled 70 patients with symptomatic MGD and unstable tear film [tear breakup time (TBUT) <8 seconds]. Patients were randomized to topical CsA (0.05%; group A) and 0.5% carboxymethylcellulose (control; group B) instilled twice daily for 3 months. Ocular Surface Disease Index (OSDI), lid margin inflammation, meibomian gland expression, conjunctival injection, corneal and interpalpebral dye staining, noninvasive tear breakup time (NIBUT) using the Tearscope Plus and invasive fluorescein tear breakup time (FBUT), and Schirmer I test were performed. Results: At the 3-month evaluation, mean OSDI, NIBUT and FBUT, lid margin inflammation, meibomian gland expressibility, and tarsal injection showed significant improvement from baseline in group A (P < 0.01, P < 0.01, P < 0.001, P < 0.05, and P < 0.001, respectively). In group B, only the OSDI improved significantly from baseline at 3 months (P = 0.003). TBUTs (NIBUT and FBUT) were significantly longer in group A at all visits, and the mean change of TBUTs from baseline was also significantly greater in group A at 3 months (P < 0.001). Conclusions: Topical CsA 0.05% twice daily may be helpful in the treatment of MGD mainly by improving tear film stability.

Efficacy of cultivated corneal epithelial stem cells for ocular surface reconstruction

Purpose To investigate the clinical outcomes of cultivated corneal limbal epithelial transplantation (CLET) using human amniotic membrane for corneal limbal stem-cell deficiency. Methods Prospective, noncomparative case series. Eighteen patients (19 eyes) with severe ocular surface diseases were chosen to undergo CLET using human amniotic membrane. Twelve eyes received auto-CLET, and seven eyes received allo-CLET. Clinical outcomes of corneal surface epithelialization, conjunctivalization, inflammation, visual acuity, graft status, and complications were observed. Results Corneal epithelium cultivated on amniotic membrane (two to four layers) was positive for molecular markers p63, ABCG2, CK3, and CK12. The mean patient age was 44.7 ± 15.2 years. A successful clinical outcome, defined as corneal epithelialization without central conjunctivalization or severe inflammation, was obtained in 14 (73.7%) of 19 eyes (mean follow-up 26.1 ± 13.5 months; range 6–47). A histopathologic success, defined as absence of goblet cells at the central cornea, was achieved in 12 (63.2%) eyes. Clinical failures occurred in five (26.3%) of 19 eyes, and histopathologic failures occurred in seven (36.8%) of 19 eyes. Survival analysis at 1 year showed that the clinical success rate was 77.9% and the pathological success rate was 72.3%. Fourteen of 19 (73.7%) eyes had visual acuity improvements after CLET. Six cases underwent penetrating keratoplasty; five of these grafts remained clear after 20.4 ± 6.9 months (range, 12–31) of follow-up. Complications included infectious keratitis (three cases) and recurrent symblepharon (one case). All complicated cases had lid abnormalities. Factors affecting the final clinical outcomes were lid abnormalities, abnormal corneal stromal beds, and complications. Conclusion CLET can successfully restore ocular surface damage in most cases with corneal limbal stem cell deficiency.