Daniel Meller

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.

EX VIVO PRESERVATION AND EXPANSION OF HUMAN LIMBAL EPITHELIAL STEM CELLS ON AMNIOTIC MEMBRANE CULTURES

Background/aim: Amniotic membrane (AM) transplantation effectively expands the remaining limbal epithelial stem cells in patients with partial limbal stem cell deficiency. The authors investigated whether this action could be produced ex vivo. Methods: The outgrowth rate on AM was compared among explants derived from human limbus, peripheral cornea, and central cornea. For outgrowth of human limbal epithelial cells (HLEC), cell cycle kinetics were measured by BrdU labelling for 1 or 7 days, of which the latter was also chased in primary cultures, secondary 3T3 fibroblast cultures, and in athymic Balb/c mice following a brief treatment with a phorbol ester. Epithelial morphology was studied by histology and transmission electron microscopy, and phenotype was defined by immunostaining with monoclonal antibodies to keratins and mucins. Results: Outgrowth rate was 0/22 (0%) and 2/24 (8.3%) for central and peripheral corneal explants, respectively, but was 77/80 (96.2%) for limbal explants (p <0.0001). 24 hour BrdU labelling showed a uniformly low (that is, less than 5%) labelling index in 65% of the limbal explants, but a mixed pattern with areas showing a high (that is, more than 40%) labelling index in 35% of limbal explants, and in all (100%) peripheral corneal explants. Continuous BrdU labelling for 7 days detected a high labelling index in 61.5% of the limbal explants with the remainder still retaining a low labelling index. A number of label retaining cells were noted after 7 day labelling followed by 14 days of chase in primary culture or by 21 days of chase after transplantation to 3T3 fibroblast feeder layers. After exposure to phorbol 12-myristate 13-acetate for 24 hours and 7 day labelling, HLEC transplanted in athymic mice still showed a number of label retaining basal cells after 9 days of chase. HLEC cultured on AM were strongly positive for K14 keratin and MUC4 and slightly positive in suprabasal cells for K3 keratin but negative for K12 keratin, AMEM2, and MUC5AC. After subcutaneous implantation in athymic mice, the resultant epithelium was markedly stratified and the basal epithelial cells were strongly positive for K14 keratin, while the suprabasal epithelial cells were strongly positive for K3 keratin and MUC4, and the entire epithelium was negative for K12 keratin and MUC5A/C. Conclusions: These data support the notion that AM cultures preferentially preserve and expand limbal epithelial stem cells that retain their in vivo properties of slow cycling, label retaining, and undifferentiation. This finding supports the feasibility of ex vivo expansion of limbal epithelial stem cells for treating patients with total limbal stem cell deficiency using a small amount of donor limbal tissue.

Conjunctivochalasis: Literature Review and Possible Pathophysiology

Conjunctivochalasis, defined as a redundant conjunctiva typically located between the globe and the lower eyelid, is not uncommon. However, it is often overlooked, as it may be considered a normal senile change. Conjunctivochalasis can cause a spectrum of symptoms, ranging from aggravation of a dry eye at the mild stage, to disturbance of tear outflow at the moderate stage, and exposure problems at the severe stage. Clinical recognition of its pathogenic role helps differentiate conjunctivochalasis from other diseases that may generate similar symptoms. For symptomatic patients, topical lubricants can be tried, but they are frequently unsuccessful, and surgical excision may be required. To guide future investigation into the clinical significance of conjunctivochalasis, a comprehensive grading system and a hypothetical pathophysiology are proposed. Special attention is given to the relationship of conjunctivochalasis to tear dynamics.

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.

Amniotic membrane transplantation for symptomatic conjunctivochalasis refractory to medical treatments.

Purpose. To determine whether preserved human amniotic membrane can restore the large conjunctival defect created during surgical removal of conjunctivochalasis. Methods. Amniotic membrane transplantation was performed at two facilities in 40 consecutive patients (47 eyes) with symptomatic conjunctivochalasis refractory to conventional treatments. Results. The majority of patients were elderly (73.1 ± 9.7 years) and women (75%). Over a follow-up period of 6.9 ± 4.3 months, 46 (97.8%) eyes recovered smooth, quiet, and stable conjunctival surfaces. Epithelial defects healed in 16.5 ± 7.3 days. Episodic epiphora was resolved in 24 of 30 (83.3%) eyes and improved in five other eyes. Notable relief was also noted for such symptoms as fullness or heaviness (19/19, 100%), sharp pain (6/6, 100%), redness (14/17, 88.2%), tiredness (17/20, 80.9%), itching (11/13, 78.6%), blurry or decreased vision (6/8, 75%), burning (8/13, 61.5%), foreign body sensation (8/13, 61.5%), and crust formation (1/2, 50%). Complications included focal inflammation of the host conjunctiva adjacent to the graft (six eyes), scar formation (five eyes), and suture-induced granuloma (one eye). Conclusion. Amniotic membrane transplantation can be considered as an effective means for conjunctival surface reconstruction during removal of conjunctivochalasis.

GS-101 Antisense Oligonucleotide Eye Drops Inhibit Corneal Neovascularization Interim Results of a Randomized Phase II Trial

PURPOSE Pathologic corneal neovascularization not only reduces corneal transparency and visual acuity, but also is one of the most significant preoperative and postoperative risk factors for graft rejection after corneal transplantation. The aim of this study was to test tolerability and efficacy of gene signal (GS)-101 eye drops, an antisense oligonucleotide against insulin receptor substrate-1, versus placebo on inhibition of progressive corneal neovascularization. DESIGN Randomized, double-blind, multicenter, phase II clinical study. PARTICIPANTS AND CONTROLS Interim analysis on 40 patients with progressive corneal neovascularization resulting from various underlying diseases being nonresponsive to conventional therapy. INTERVENTIONS Four groups of 10 patients were treated for 3 months in this dose-finding study comparing 3 doses of GS-101 (eye drops twice daily; 43, 86, and 172 microg/day total) with placebo (10 patients per group). MAIN OUTCOME MEASURES The primary end point was the area covered by pathologic corneal blood vessels, which was measured morphometrically on digitized slit-lamp pictures using image analysis techniques. RESULTS GS-101 eye drops were well tolerated. All serious and 95% of all other adverse events were categorized by the investigators as unrelated. In 3 patients, there was a potentially related side effect of ocular surface discomfort. At a dose of 86 microg/day (43 microg/drop), GS-101 eye drops produced a significant inhibition and regression of corneal neovascularization (-2.04+/-1.57% of total corneal area; P = 0.0047), whereas the low dose tended to stabilize it (0.07+/-2.94%; P = 0.2088) compared with placebo (0.89+/-2.15%), where corneal neovascularization progressed in all patients. There was no apparent benefit to the higher dose (1.60+/-7.63%). CONCLUSIONS The interim results of this phase II study suggest that GS-101 eye drops at an optimal dose of 86 microg/day are an effective and noninvasive approach specifically to inhibit and regress active corneal angiogenesis, a major risk factor for corneal graft transplantation and graft rejection. Safety concerns were not detected. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

Midterm results of cultivated autologous and allogeneic limbal epithelial transplantation in limbal stem cell deficiency.

BACKGROUND Limbal stem cell deficiency (LSCD) leads to growth of abnormal fibro-vascular pannus tissue onto the corneal surface as well as chronic inflammation and impaired vision. Our aim was to investigate the clinical outcome of ocular surface reconstruction in LSCD using limbal epithelial cells expanded on amniotic membrane (AM). METHODS Forty-four eyes of 38 patients (27 male, 11 female) with total (n = 32) or partial (n = 12) LSCD were treated by transplantation of autologous (n = 30) or allogeneic (n = 14) limbal epithelial cells expanded on intact AM. LSCD was caused by chemical and thermal burns (n = 22), pterygium (n = 9), congenital aniridia (n = 6), tumor excision (n = 2), perforating eye injury, mitomycin C, epidermolysis bullosa, bilateral graft-versus-host disease and chlamydial conjunctivitis (each n = 1). RESULTS Mean follow-up time was 28.5 +/- 14.9 months. The corneal surface could be reconstructed to full stability in 30 (68%), and clear central cornea was achieved in 37 (84%) eyes. Grafting was significantly more successful in eyes treated by autologous than by allogeneic transplantation (76.7 vs. 50%, p < 0.05). The corneal surface could be successfully restored in 10 (83.3%) eyes with partial LSCD and in 20 (63.3%) eyes with total LSCD. Visual acuity (VA) increased significantly in 32 (73%) eyes, was stable in 10 (23%) eyes and decreased in 2 (4%) eyes. Mean VA increased significantly (p < 0.0001), from preoperative 1.7 +/- 0.9 log MAR (20/1,000) to 0.9 +/- 0.7 log-MAR (20/160). VA increased significantly after both autologous (p < 0.0001) and allogeneic transplantation (p < 0.005). CONCLUSIONS In most patients with LSCD, transplantation of limbal epithelium cultivated on intact AM restores the corneal surface and results in significantly increased VA.

Anti-CD20 monoclonal antibody therapy in relapsed MALT lymphoma of the conjunctiva

Abstract:  Low‐grade non‐Hodgkins lymphomas of the conjunctiva may be cured by radiotherapy, but complications are frequent and relapses may occur. Other treatment modalities including resection, cryotherapy, injection of interferon‐α or systemic chemotherapy have been used with varying success. We treated two patients with relapsed extranodal marginal zone lymphoma (ENMZL) of mucosa‐associated lymphoid tissue (MALT) of the conjunctiva with the anti‐CD20 monoclonal antibody rituximab (375 mg/m2 intravenously once weekly for 4 wk) which has previously been shown to be effective in a variety of other B‐cell non‐Hodgkins lymphomas. Treatment was well tolerated and resulted in one partial and one complete remission. With a follow‐up of 32 or 30 months, respectively, further recurrences have not been observed. Rituximab is a highly effective and well‐tolerated treatment of conjunctival MALT lymphoma, which may not only be of value in relapse, but also in cases of contraindication to radiotherapy.

Ex Vivo Preservation and Expansion of Human Limbal Epithelial Stem Cells on Amniotic Membrane for Treating Corneal Diseases with Total Limbal Stem Cell Deficiency

The normal ocular surface is composed of corneal, limbal, and conjunctival epithelial cells, which maintain its integrity. Severe damage to limbal epithelial cells from Stevens-Johnson syndrome (SJS), ocular cicatricial pemphigoid (OCP) and chemical burns may lead to loss of the limbal epithelial cells.1 Such limbal cell deficiencies are some of the greatest challenges facing todays clinician.2–6 During the chronic cicatricial phase, most patients with ocular surface disease—experience numerous problems, including symblepharon, persistent epithelial defects, conjunctivalization, and pathological keratinization. Some of these problems can be managed by antibiotics, corticosteroids and immunosuppressants. However, the pathological keratinization of ordinarily nonkeratinized corneal and conjunctival epithelium is a serious and potentially debilitating problem that is difficult to manage pharmacologically.

Original articleGS-101 Antisense Oligonucleotide Eye Drops Inhibit Corneal Neovascularization: Interim Results of a Randomized Phase II Trial

PURPOSE Pathologic corneal neovascularization not only reduces corneal transparency and visual acuity, but also is one of the most significant preoperative and postoperative risk factors for graft rejection after corneal transplantation. The aim of this study was to test tolerability and efficacy of gene signal (GS)-101 eye drops, an antisense oligonucleotide against insulin receptor substrate-1, versus placebo on inhibition of progressive corneal neovascularization. DESIGN Randomized, double-blind, multicenter, phase II clinical study. PARTICIPANTS AND CONTROLS Interim analysis on 40 patients with progressive corneal neovascularization resulting from various underlying diseases being nonresponsive to conventional therapy. INTERVENTIONS Four groups of 10 patients were treated for 3 months in this dose-finding study comparing 3 doses of GS-101 (eye drops twice daily; 43, 86, and 172 microg/day total) with placebo (10 patients per group). MAIN OUTCOME MEASURES The primary end point was the area covered by pathologic corneal blood vessels, which was measured morphometrically on digitized slit-lamp pictures using image analysis techniques. RESULTS GS-101 eye drops were well tolerated. All serious and 95% of all other adverse events were categorized by the investigators as unrelated. In 3 patients, there was a potentially related side effect of ocular surface discomfort. At a dose of 86 microg/day (43 microg/drop), GS-101 eye drops produced a significant inhibition and regression of corneal neovascularization (-2.04+/-1.57% of total corneal area; P = 0.0047), whereas the low dose tended to stabilize it (0.07+/-2.94%; P = 0.2088) compared with placebo (0.89+/-2.15%), where corneal neovascularization progressed in all patients. There was no apparent benefit to the higher dose (1.60+/-7.63%). CONCLUSIONS The interim results of this phase II study suggest that GS-101 eye drops at an optimal dose of 86 microg/day are an effective and noninvasive approach specifically to inhibit and regress active corneal angiogenesis, a major risk factor for corneal graft transplantation and graft rejection. Safety concerns were not detected. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.