Jibran Mohamed-Noriega

Corneal Melting after Collagen Cross-Linking for Keratoconus in a Thin Cornea of a Diabetic Patient Treated with Topical Nepafenac: A Case Report with a Literature Review

Purpose: To report the case of a 50-year-old woman with diabetes that presented with corneal melting and perforation 6 weeks after collagen cross-linking (CxL) for keratoconus (KC) and postoperative use of nepafenac eye drops, a nonsteroidal anti-inflammatory drug (NSAID). Methods: This is a case report of a patient with diabetes, KC and a thin cornea that had undergone left eye corneal CxL at a different hospital followed by postoperative use of nepafenac eye drops for 6 weeks. Results: The patient presented for the first time to our clinic with left corneal melting, perforation and iris prolapse 6 weeks after corneal CxL and topical nepafenac use. She was treated with a left eye tectonic penetrating keratoplasty, extracapsular cataract extraction, intraocular lens implantation and pupilloplasty. Conclusions: The corneal melting and perforation in this patient was associated with multiple risk factors: (1) nepafenac eye drop use, (2) CxL in a cornea thinner than 400 µm and (3) diabetes. The recommended corneal thickness limits should be respected. Topical NSAIDs should be used with caution if used as postoperative treatment after corneal CxL and in patients with diabetes, epithelial defect or delayed healing, because of the possible increased risk for corneal melting when multiple risk factors are observed.

Olfactomedin-like 3 (OLFML3) gene expression in baboon and human ocular tissues: cornea, lens, uvea, and retina

Olfactomedin‐like is a family of polyfunctional polymeric glycoproteins. This family has at least four members. One member of this family is OLFML3, which is preferentially expressed in placenta but is also detected in other adult tissues including the liver and heart. However, its orthologous rat gene is expressed in the iris, sclera, trabecular meshwork, retina, and optic nerve.

Expression of growth hormone gene in the baboon eye

&NA; The human growth hormone (GH) locus is comprised by two GH (GH1 and GH2) genes and three chorionic somatomammotropin (CSH1, CSH2 and CSH‐L) genes. While GH1 is expressed in the pituitary gland, the rest are expressed in the placenta. However, GH1 is also expressed in several extrapituitary tissues, including the eye. So to understand the role of this hormone in the eye we used the baboon (Papio hamadryas), that like humans has a multigenic GH locus; we set up to investigate the expression and regulation of GH locus in adult and fetal baboon ocular tissues. We searched in baboon ocular tissues the expression of GH1, GH2, CSH1/2, Pit1 (pituitary transcription factor 1), GHR (growth hormone receptor), GHRH (growth hormone releasing hormone), GHRHR (growth hormone releasing hormone receptor), SST (somatostatin), SSTR1 (somatostatin receptor 1), SSTR2 (somatostatin receptor 2), SSTR3 (somatostatin receptor 3), SSTR4 (somatostatin receptor 4), and SSTR5 (somatostatin receptor 5) mRNA transcripts and derived proteins, by qPCR and immunofluorescence assays, respectively. The transcripts found were characterized by cDNA cloning and sequencing, having found only the one belonging to GH1 gene, mainly in the retina/choroid tissues. Through immunofluorescence assays the presence of GH1 and GHR proteins was confirmed in several retinal cell layers. Among the possible neuroendocrine regulators that may control local GH1 expression are GHRH and SST, since their mRNAs and proteins were found mainly in the retina/choroid tissues, as well as their corresponding receptors (GHRH and SSTR1‐SSTR5). None of the ocular tissues express Pit1, so gene expression of GH1 in baboon eye could be independent of Pit1. We conclude that to understand the regulation of GH in the human eye, the baboon offers a very good experimental model. HighlightsThis is the first report of the presence of GH in the baboon eye.The GH transcript isolated from the baboon eye confirms a new expression site for this hormone.GH and GHR proteins were present not only in retinal ganglion cells (RGC) but also in the entire retina.GH and its GHR were both seen localized in the cytoplasm as well as in the nucleus by immunohistochemistry.GH may trigger both autocrine and paracrine specific action in different retinal cell lines in the baboon.

Olfactomedin-like 2 A and B (OLFML2A and OLFML2B) expression profile in primates (human and baboon)

BackgroundThe olfactomedin-like domain (OLFML) is present in at least four families of proteins, including OLFML2A and OLFML2B, which are expressed in adult rat retina cells. However, no expression of their orthologous has ever been reported in human and baboon.ObjectiveThe aim of this study was to investigate the expression of OLFML2A and OLFML2B in ocular tissues of baboons (Papio hamadryas) and humans, as a key to elucidate OLFML function in eye physiology.MethodsOLFML2A and OLFML2B cDNA detection in ocular tissues of these species was performed by RT-PCR. The amplicons were cloned and sequenced, phylogenetically analyzed and their proteins products were confirmed by immunofluorescence assays.ResultsOLFML2A and OLFML2B transcripts were found in human cornea, lens and retina and in baboon cornea, lens, iris and retina. The baboon OLFML2A and OLFML2B ORF sequences have 96% similarity with their human’s orthologous. OLFML2A and OLFML2B evolution fits the hypothesis of purifying selection. Phylogenetic analysis shows clear orthology in OLFML2A genes, while OLFML2B orthology is not clear.ConclusionsExpression of OLFML2A and OLFML2B in human and baboon ocular tissues, including their high similarity, make the baboon a powerful model to deduce the physiological and/or metabolic function of these proteins in the eye.

A Case of Bilateral Pigment Dispersion Syndrome Following Many Years of Uninterrupted Treatment With Atropine 1% for Bilateral Congenital Cataracts

Purpose: Describe an unusual case of bilateral pigment dispersion syndrome (PDS) following years of uninterrupted treatment with atropine 1% for bilateral congenital cataracts, speculate on potential mechanisms leading to this condition. Design: This is a case report. Case: A 45-year-old white patient on long-term treatment with atropine 1% ointment since his infancy for bilateral congenital cataracts developed PDS with secondary ocular hypertension. Results: The patient showed all the hallmarks of PDS with secondary ocular hypertension. An anterior segment Swept-Source optical coherence tomography was obtained to review the iris profile. The patient showed good pressure response to topical prostaglandin therapy. Conclusions: This is the second case report of PDS in a patient with chronic use of topical atropine. The proposed mechanisms for pigment dispersion are discussed and the possibility raised of dispersion being a potential side effect of the drug.