Role of high resolution optical coherence tomography in diagnosing ocular surface squamous neoplasia with coexisting ocular surface diseases.

PURPOSE: Coexistence of an ocular surface disease can mask the typical features of ocular surface squamous neoplasia (OSSN). The purpose of this study was to evaluate high resolution optical coherence tomography (HR-OCT) as an adjunct in the detection and differentiation of OSSN within coexisting ocular surface pathologies. METHODS: Retrospective study of 16 patients with ocular surface disease and lesions suspicious for OSSN that were evaluated with HR-OCT. HR-OCT images of the lesions were taken to look for evidence of OSSN. Biopsies were performed in all cases, and the HR-OCT findings were compared to the histological results. RESULTS: Of the 16 patients with OSSN and a coexisting ocular surface disease, 12 were found to have OSSN by HR-OCT and all were subsequently confirmed by biopsy. Two patients had OSSN with rosacea, one with pingueculum, two within pterygia, one with Salzmann' nodular degeneration, six with limbal stem cell deficiency (LSCD)/scarring. In all 12 cases HR-OCT images revealed classical findings of hyper-reflective, thickened epithelium and an abrupt transition from normal to abnormal epithelium. OSSN was ruled out by HR-OCT in four cases (2 Salzmann's, 1 mucous membrane pemphigoid, and 1 LSCD). Negative findings were confirmed by biopsy. HR-OCT was used to follow resolution of the OSSN in positive cases, and it detected recurrence in 1 case. CONCLUSIONS: While histopathology is the gold standard in the diagnosis of OSSN, HR-OCT can be used to noninvasively detect the presence of OSSN in patients with coexisting ocular conditions.

Limbal stem cell transplantation: current perspectives.

Regeneration of the corneal surface after an epithelial insult involves division, migration, and maturation of a specialized group of stem cells located in the limbus. Several insults, both intrinsic and extrinsic, can precipitate destruction of the delicate microenvironment of these cells, resulting in limbal stem cell deficiency (LSCD). In such cases, reepithelialization fails and conjunctival epithelium extends across the limbus, leading to vascularization, persistent epithelial defects, and chronic inflammation. In partial LSCD, conjunctival epitheliectomy, coupled with amniotic membrane transplantation, could be sufficient to restore a healthy surface. In more severe cases and in total LSCD, stem cell transplantation is currently the best curative option. Before any attempts are considered to perform a limbal stem cell transplantation procedure, the ocular surface must be optimized by controlling causative factors and comorbid conditions. These factors include adequate eyelid function or exposure, control of the ocular surface inflammatory status, and a well-lubricated ocular surface. In cases of unilateral LSCD, stem cells can be obtained from the contralateral eye. Newer techniques aim at expanding cells in vitro or in vivo in order to decrease the need for large limbal resection that may jeopardize the "healthy" eye. Patients with bilateral disease can be treated using allogeneic tissue in combination with systemic immunosuppressive therapy. Another emerging option for this subset of patients is the use of noncorneal cells such as mucosal grafts. Finally, the use of keratoprosthesis is reserved for patients who are not candidates for any of the aforementioned options, wherein the choice of the type of keratoprosthesis depends on the severity of the disease. In summary, limbal stem cell transplantation improves both vision and quality-of-life in patients with ocular surface disorders associated with LSCD, and overall, the use of autologous tissue offers the best results. Future studies aim at improving cellular expansion and finding different sources of stem cells.

Autologous simple limbal epithelial transplantation for unilateral limbal stem cell deficiency: multicentre results.

PURPOSE: To report outcomes of autologous simple limbal epithelial transplantation (SLET) performed for unilateral limbal stem cell deficiency (LSCD) at multiple centres worldwide. METHODS: In this retrospective, multicentre, interventional case series, records of patients who had undergone autologous SLET for unilateral LSCD, with a minimum of 6 months of follow-up, were reviewed. The primary outcome measure was clinical success, defined as a completely epithelised, avascular corneal surface. Kaplan-Meier survival curves were constructed and survival probability was calculated. A Cox proportional hazards analysis was done to assess association of preoperative characteristics with risk of failure. Secondary outcome measures included the percentage of eyes achieving visual acuity of 20/200 or better, percentage of eyes gaining two or more Snellen lines and complications encountered. RESULTS: 68 eyes of 68 patients underwent autologous SLET, performed across eight centres in three countries. Clinical success was achieved in 57 cases (83.8%). With a median follow-up of 12 months, survival probability exceeded 80%. Presence of symblepharon (HR 5.8) and simultaneous keratoplasty (HR 10.8) were found to be significantly associated with a risk of failure. 44 eyes (64.7%) achieved a visual acuity of 20/200 or better, and 44 eyes (64.7%) gained two or more Snellen lines. Focal recurrences of pannus were noted in 21 eyes (36.8%) with clinical success. CONCLUSION: Autologous SLET is an effective and safe modality for treatment of unilateral LSCD. Clinical success rates and visual acuity improvement are equal to or better than those reported with earlier techniques.

Modified simple limbal epithelial transplantation using cryopreserved amniotic membrane for unilateral limbal stem cell deficiency.

PURPOSE: To report the results of simple limbal epithelial transplantation using a double-layered cryopreserved amniotic membrane graft for the management of unilateral limbal stem cell deficiency. DESIGN: Retrospective case series. METHODS: Four consecutive patients with unilateral partial (2 eyes) and total (2 eyes) limbal stem cell deficiency secondary to ocular surface burns (2 eyes), trauma (1 eye) and conjunctival melanoma treatment (1 eye) underwent modified simple limbal epithelial transplantation at Bascom Palmer Eye Institute. Preoperative and postoperative visual acuity and quality of corneal epithelium were evaluated. RESULTS: The patients were followed up for a mean ± standard deviation of 7.5 ± 1.3 months. The donor eye returned to a healthy state in all patients. All patients had significant improvement in visual acuity and resolution of ocular pain in the affected eye. Regular corneal epithelium and a quiet ocular surface were obtained in all patients by a median of 4 weeks. CONCLUSIONS: Compared with the currently used surgical techniques for management of limbal stem cell deficiency, simple limbal epithelial transplantation seems to be a safe, reproducible, and effective alternative. The use of a double layer allows more protection for the explant without impacting outcomes. Also, the use of cryopreserved amniotic membrane allows surgeons to perform this procedure in the Unites States. More cases with longer follow-up will be needed to assess the outcomes further.

Gamma-irradiated corneas as carriers for the Boston type 1 keratoprosthesis: advantages and outcomes in a surgical mission setting.

PURPOSE: The Boston keratoprosthesis (KPro) is the most commonly used KPro worldwide. There are limited data on the outcomes when irradiated corneas are used as KPro carriers. We report a retrospective analysis of corneal transplantations performed in a regular surgical mission setting in Beirut, Lebanon, using the Boston KPro type 1 and gamma-irradiated carrier corneas, and we describe visual outcomes, complications, and retention percentage. METHODS: We conducted a retrospective analysis of 17 consecutive eyes from 16 patients who underwent Boston KPro type 1 implantation at the Beirut Eye Specialist Hospital between December 2010 and July 2012. Patient medical records were reviewed for preoperative, intraoperative, and postoperative details. RESULTS: Postoperatively, 9 (52.9%), 5 (29.4%), and 2 (11.7%) eyes had a corrected visual acuity of 20/400 or better, 20/100 or better, and 20/40 or better, respectively, at the most recent follow-up visit. A total of 16 eyes (94.1%) improved in corrected visual acuity over the course of follow-up. Overall, 13 eyes (76.4%) developed at least 1 complication after surgery. Retroprosthetic membrane formation was the most common complication, occurring in 10 eyes (58.8%). Neither infectious keratitis nor corneal stromal necrosis was noted during the follow-up period. The retention percentage was 94.1%. CONCLUSIONS: The visual acuity outcomes, incidence of complications, and retention percentage of the KPro using gamma-irradiated carrier corneas are comparable with the outcomes of KPro implantation reported in the literature using fresh grafts as carriers. KPro with irradiated corneal carrier grafts seems to be an effective option to increase the supply of transplantation suitable corneas in remote areas, where fresh corneal grafts may be scarce.

Renal medullary carcinoma in a patient with sickle-cell disease.

BACKGROUND: A 36-year-old black male with sickle-cell disease, asthma, and dyslipidemia presented with shortness of breath, chest pain, lethargy, and recent fever. Physical examination revealed mild respiratory distress. INVESTIGATIONS: Chest X-ray, CT, abdominal ultrasound, and MRI. DIAGNOSIS: Renal medullary carcinoma.