Presentation, diagnosis and management of limbal stem cell deficiency

The human corneal surface epithelium is continuously repopulated by the limbal stem cells [LSCs]. Limbal Stem Cell Deficiency [LSCD] can lead to corneal opacity and vascularization, with consequent visual impairment or blindness. Many acquired and congenital diseases can lead to LCSD by direct injury to the LSCs, destruction of LSC niche, or both. Based on the severity of the disease, LSCD can present with various symptoms and signs. Although LSCD can be detected clinically, laboratory tests are necessary to confirm the diagnosis and monitor the disease progression. This article concisely reviews the clinical presentation, techniques for diagnosis and management of LSCD

Update on limbal stem cell transplantation

Limbal epithelial stem cells are the primary source of corneal epithelial cell regeneration. Limbal stem cell deficiency [LSCD] can develop in traumatic, immunologic, or genetic diseases that affect the ocular surface. LSCD leads to conjunctivalization, with corneal vascularization and opacification and subsequent loss of vision. Limbal stem cell transplantation is a surgical treatment to address LSCD and restore a corneal epithelial phenotype. Based on the source of cells, limbal transplant can be autologous or allogenic. Many surgical techniques are defined according to the source of the stem cells and the carrier tissues that are used. More recently, ex vivo expanded bioengineered epithelial cells have been used to reconstruct the corneal surface using autologous cells to eliminate the risk of rejection. Before transplantation, a systematic exam of the lids, eyelashes, fornices, and aqueous tears is mandatory and every effort should be made to optimize ocular surface health and control inflammation to enhance the chances of graft survival. Postoperative care is also another major determinant of success. Any factor that destabilizes the ocular surface needs to be addressed. In addition, systemic and topical immunosuppressants are also needed in all allograft recipients. In addition to pre-operative and postoperative care and the surgery itself, the etiology of LSCD also has an impact on the outcome. The prognosis of inflammatory diseases such as Stevens-Johnson syndrome is the worst among disorders causing LSCD

Correlation between retinal nerve fiber layer thickness by optical coherence tomography and perimetric parameters in optic atrophy

To investigate the correlation between retinal nerve fiber layer [RNFL] thickness determined by optical coherence tomography [OCT] and visual field [VF] parameters in patients with optic atrophy. This study was performed on 35 eyes of 28 patients with optic atrophy. RNFL thickness was measured by OCT [Carl Zeiss, Jena, Germany] and automated perimetry was performed using the Humphrey Field Analyzer [Carl Zeiss, Jena, Germany]. The correlation between RNFL thickness and VF parameters was evaluated. Mean global RNFL thickness was 44.9 +/- 27.5] which was significantly correlated with mean deviation score on automated perimetry [r=0.493, P=0.003]; however, no significant correlation was observed between visual field pattern standard deviation and the corresponding quadrantic RNFL thickness. In a similar manner, no significant association was found between visual acuity and RNLF thickness. Mean global RNFL thickness as determined by OCT seems to be correlated with VF defect depth as represented by the mean deviation score on Humphrey VF testing. OCT may be used as an objective diagnostic tool in the evaluation of patients with optic atrophy