Corneal Neurotization for Neurotrophic Keratopathy: Clinical Outcomes and In Vivo Confocal Microscopic and Histopathological Findings

Purpose: To describe the long-term outcomes and in vivo confocal microscopic (IVCM) and histopathological findings after corneal neurotization surgery. / Methods: We included 2 patients who underwent corneal neurotization surgery for severe unilateral neurotrophic keratopathy secondary to cerebellopontine angle meningioma. Corneal sensation was measured using the Cochet–Bonnet esthesiometer (CBE) (0–60 mm). IVCM was performed using the Heidelberg HRT3 Rostock Corneal Module. Histopathological examination was performed on the excised corneoscleral disc of patient 2. / Results: In patient 1, corneal sensation improved from 0 mm preoperatively to 60 mm in all 4 quadrants by 2 years postoperatively and was maintained at 5 years postoperatively with identifiable subbasal and stromal corneal nerves on IVCM. In patient 2, corneal sensation improved from 0 mm preoperatively to 10 mm in 3 quadrants (9 months postoperatively) but returned to 0 mm in all quadrants by 2 years postoperatively. IVCM failed to identify any subbasal and stromal corneal nerves. At 5 years postoperatively, evisceration was performed to ameliorate uncontrolled and persistent ocular pain and poor cosmesis. Histopathological examination of the excised corneoscleral disc confirmed the presence of normal-sized, central corneal stromal nerve fascicles but without direct continuity with the transplanted perilimbal nerve bundles. / Conclusions: Our study elucidates the mechanism of corneal neurotization surgery at a cellular level. Although only 1 patient achieved long-term improvement in corneal sensation postoperatively, the findings on IVCM and histopathological examination suggest that partial regeneration/maintenance of corneal nerves after corneal neurotization surgery is likely attributed to the paracrine neurotrophic support, instead of direct sprouting, from the perilimbal transplanted nerve fascicles

Expression of the SST receptor 2 in uveal melanoma is not a prognostic marker

Introduction: Uveal melanoma (UM) cells and neurohormone-producing cells both originate from the neural crest. Somatostatin receptors subtype 2 (SSTR2) are over-expressed in several tumors, often from neuroendocrine origin, and synthetic antagonists like octreotide and octreotate are being used as diagnostic or therapeutic agents. We investigated the SSTR2 expression in UM, and determined whether this expression was related to prognosis of the disease. Materials and methods: UM cell lines and fresh primary UM samples were tested for SSTR2 expression by autoradiography (AR) using 125I-Tyr3-octreotate. Furthermore, UM cell lines were analyzed for SSTR2 mRNA expression with quantitative real-time RT-PCR. Results: Using AR, cell-surface SSTR2 expression was demonstrated in two UM metastatic cell lines, but no expression was detected in three cell lines derived from primary UM. However, all primary and metastatic UM cell lines showed mRNA expression levels for SSTR2 using quantitative real-time RT-PCR. Only three of 14 primary UM demonstrated moderate SSTR2 expression, and this expression was not significantly associated with tumor-free survival or any tested prognostic factor. Conclusions: Based on the rare and low expression of SSTR2 found in primary UM specimens and in UM cell lines, we conclude that SSTR2 is not widely expressed in UM. Furthermore, SSTR2 expression was not associated with tumor-free survival and prognostic factors. Therefore SSTR2 is not suited as prognostic marker or therapeutic target in UM

Multiple receptor tyrosine kinases are expressed in adult rat retinal ganglion cells as revealed by single-cell degenerate primer polymerase chain reaction

BACKGROUND: To achieve a better understanding of the repertoire of receptor tyrosine kinases (RTKs) in adult retinal ganglion cells (RGCs) we performed polymerase chain reaction (PCR), using degenerate primers directed towards conserved sequences in the tyrosine kinase domain, on cDNA from isolated single RGCs univocally identified by retrograde tracing from the superior colliculi.RESULTS: All the PCR-amplified fragments of the expected sizes were sequenced, and 25% of them contained a tyrosine kinase domain. These were: Axl, Csf-1R, Eph A4, Pdgfrbeta, Ptk7, Ret, Ros, Sky, TrkB, TrkC, Vegfr-2, and Vegfr-3. Non-RTK sequences were Jak1 and 2. Retinal expression of Axl, Csf-1R, Pdgfrbeta, Ret, Sky, TrkB, TrkC, Vegfr-2, and Vegfr-3, as well as Jak1 and 2, was confirmed by PCR on total retina cDNA. Immunodetection of Csf-1R, Pdgfralpha/beta, Ret, Sky, TrkB, and Vegfr-2 on retrogradely traced retinas demonstrated that they were expressed by RGCs. Co-localization of Vegfr-2 and Csf-1R, of Vegfr-2 and TrkB, and of Csf-1R and Ret in retrogradely labelled RGCs was shown. The effect of optic nerve transection on the mRNA level of Pdgfrbeta, Csf-1R, Vegfr-2, Sky, and Axl, and of the Axl ligands Gas6 and ProteinS, was analysed. These analyses show transection-induced changes in Axl and ProteinS mRNA levels.CONCLUSIONS: The repertoire of RTKs expressed by RGCs is more extensive than previously anticipated. Several of the receptors found in this study, including Pdgfrbeta, Csf-1R, Vegfr-2, Sky, and Axl, and their ligands, have not previously been primarily associated with retinal ganglion cells

PAX6 mutation in association with ptosis, cataract, iris hypoplasia, corneal opacification and diabetes: A new variant of familial aniridia?

Background: We report a family with ptosis, cataract, iris hypoplasia and gradual corneal opacification occurring in association with a PAX6 mutation. Design: Case-series. Participants: Fourteen family members - 8 affected, 6 unaffected controls. Methods: All participants underwent ophthalmological assessment, including best-corrected visual acuity, slit-lamp-examination, pachymetry, endothelial cell-count, tonometry and dilated fundoscopy. All subjects underwent anthropometry and assessment of glycaemic status. Genetic analysis of the PAX6 gene was performed. Main Outcome Measures: Presence of ptosis, corneal, iris and lenticular changes, gycaemic and PAX6 status. Results: All eight affected subjects had ptosis with reduced levator function, anterior polar cataracts, and corneal changes of variable severity - two patients had undergone penetrating keratoplasties, with graft histology revealing conjunctival cells on the cornea and severe fibroinflammatory change. Five patients had iris hypoplasia. One patient had aphakic glaucoma and another had hypoplastic optic discs. Four of the six controls had no ocular features of this syndrome, and two had isolated mild ptosis. There was no difference in height or body mass index between cases and family controls (p>0.05), but Haemoglobin A1c was greater in the cases (median [interquartile range] 5.6(0.8) vs 5.1(0.3), p=0.028). Genetic analysis confirmed a pathogenic PAX6 mutation in exon 12 (c1439delC) in all eight patients, but none of the controls. Conclusion: This is the first report of this particular constellation of ocular signs occurring in association with a PAX6 mutation. There was no association with anthropometric features, but affected subjects had worse glycaemia than controls, which may be related to the known role of PAX6 in development of the pancreas. © 2013 Royal Australian and New Zealand College of Ophthalmologists

PAX6 mutation in association with ptosis, cataract, iris hypoplasia, corneal opacification and diabetes: A new variant of familial aniridia?

Background: We report a family with ptosis, cataract, iris hypoplasia and gradual corneal opacification occurring in association with a PAX6 mutation. Design: Case-series. Participants: Fourteen family members - 8 affected, 6 unaffected controls. Methods: All participants underwent ophthalmological assessment, including best-corrected visual acuity, slit-lamp-examination, pachymetry, endothelial cell-count, tonometry and dilated fundoscopy. All subjects underwent anthropometry and assessment of glycaemic status. Genetic analysis of the PAX6 gene was performed. Main Outcome Measures: Presence of ptosis, corneal, iris and lenticular changes, gycaemic and PAX6 status. Results: All eight affected subjects had ptosis with reduced levator function, anterior polar cataracts, and corneal changes of variable severity - two patients had undergone penetrating keratoplasties, with graft histology revealing conjunctival cells on the cornea and severe fibroinflammatory change. Five patients had iris hypoplasia. One patient had aphakic glaucoma and another had hypoplastic optic discs. Four of the six controls had no ocular features of this syndrome, and two had isolated mild ptosis. There was no difference in height or body mass index between cases and family controls (p>0.05), but Haemoglobin A1c was greater in the cases (median [interquartile range] 5.6(0.8) vs 5.1(0.3), p=0.028). Genetic analysis confirmed a pathogenic PAX6 mutation in exon 12 (c1439delC) in all eight patients, but none of the controls. Conclusion: This is the first report of this particular constellation of ocular signs occurring in association with a PAX6 mutation. There was no association with anthropometric features, but affected subjects had worse glycaemia than controls, which may be related to the known role of PAX6 in development of the pancreas. © 2013 Royal Australian and New Zealand College of Ophthalmologists