Rbpms can reliably be used as an RGC marker for quantitative evaluation in rat models of RGC degeneration, regardless of the nature and the location of the primary site of the injury and the extent of neurodegeneration.

The initial location and subsequent direction of worsening of VFD were associated with different systemic and ocular factors.

Intraocular pressure (IOP) elevation is considered as a major risk factor causing the progression of vision deterioration in glaucoma. Although it is known that the IOP level changes widely throughout the day and night, how the dark or light phase IOP elevation contributes to retinal ganglion cell (RGC) degeneration is still largely unclear. To examine the profile of IOP, modified laser photocoagulation was applied to the trabecular meshwork of Brown Norway rats and both light and dark phase IOPs were monitored approximately 1–2 times a week. The relationship between IOP elevation and RGC degeneration was investigated while RGC body loss was analyzed with Rbpms immunolabeling on retinal wholemount and axonal injury in the optic nerve was semi-quantified. The baseline awake dark and light IOPs were 30.4 ± 2.7 and 20.2 ± 2.1 mmHg respectively. The average dark IOP was increased to 38.2 ± 3.2 mmHg for five weeks after the laser treatment on 270° trabecular meshwork. However, there was no significant loss of RGC body and axonal injury. After laser treatment on 330° trabecular meshwork, the dark and light IOPs were significantly increased to 43.8 ± 4.6 and 23 ± 3.7 mmHg respectively for 5 weeks. The cumulative dark and light IOP elevations were 277 ± 86 and 113 ± 50 mmHg days respectively while the cumulative total (light and dark) IOP elevation was 213 ± 114 mmHg days. After 5 weeks, regional RGC body loss of 29.5 ± 15.5% and moderate axonal injury were observed. Axonal injury and loss of RGC body had a high correlation with the cumulative total IOP elevation (R2 = 0.60 and 0.65 respectively). There was an association between the cumulative dark IOP elevation and RGC body loss (R2 = 0.37) and axonal injury (R2 = 0.51) whereas the associations between neuronal damages and the cumulative light IOP elevation were weak (for RGC body loss, R2 = 0.01; for axonal injury, R2 = 0.26). Simple linear regression model analysis showed statistical significance for the relationships between the total cumulative IOP elevation and RGC body loss (P = 0.009), and axonal injury (P = 0.016). To examine the role of light and dark IOP elevation in RGC body loss and axonal injury, analyses for the association between different light/dark IOP factors and percentage of RGC body loss/axonal injury grading were performed and only the association between the cumulative dark IOP elevation and axonal injury showed statistical significance (P = 0.033). The findings demonstrated that the cumulative total (light and dark) IOP elevation is a risk factor to RGC degeneration in a rat model of experimental glaucoma using modified partial laser photocoagulation at 330° trabecular meshwork. Further investigations are required to understand the role of longer term light and dark phase IOP elevation contributing to the progression of degeneration in different compartments of RGCs.

Nell2 is a neuron-specific protein containing six epidermal growth factor-like domains. We have identified Nell2 as a retinal ganglion cell (RGC)-expressed gene by comparing mRNA profiles of control and RGC-deficient rat retinas. The aim of this study was to analyze Nell2 expression in wild-type and optic nerve axotomized retinas and evaluate its potential role in RGCs. Nell2-positive in situ and immunohistochemical signals were localized to irregularly shaped cells in the ganglion cell layer (GCL) and colocalized with retrogradely-labeled RGCs. No Nell2-positive cells were detected in 2 weeks optic nerve transected (ONT) retinas characterized with approximately 90% RGC loss. RT-PCR analysis showed a dramatic decrease in the Nell2 mRNA level after ONT compared to the controls. Immunoblot analysis of the Nell2 expression in the retina revealed the presence of two proteins with approximate MW of 140 and 90 kDa representing glycosylated and non-glycosylated Nell2, respectively. Both products were almost undetectable in retinal protein extracts two weeks after ONT. Proteome analysis of Nell2-interacting proteins carried out with MALDI-TOF MS (MS) identified microtubule-actin crosslinking factor 1 (Macf1), known to be critical in CNS development. Strong Macf1 expression was observed in the inner plexiform layer and GCL where it was colocalizied with Thy-1 staining. Since Nell2 has been reported to increase neuronal survival of the hippocampus and cerebral cortex, we evaluated the effect of Nell2 overexpression on RGC survival. RGCs in the nasal retina were consistently more efficiently transfected than in other areas (49% vs. 13%; n = 5, p<0.05). In non-transfected or pEGFP-transfected ONT retinas, the loss of RGCs was approximately 90% compared to the untreated control. In the nasal region, Nell2 transfection led to the preservation of approximately 58% more cells damaged by axotomy compared to non-transfected (n = 5, p<0.01) or pEGFP-transfected controls (n = 5, p<0.01).

The present study evaluates the effect of celastrol on the survival of retinal ganglion cells (RGCs) injured by optic nerve crush (ONC). Celastrol, a quinine methide triterpene extracted from the perennial vine Tripterygium wilfordii (Celastraceae), has been identified as a potential neuroprotective candidate in a comprehensive drug screen against various neurodegenerative diseases. Two weeks after ONC, the average density of remaining RGCs in retinas of animals treated with daily intraperitoneal (i.p.) injections of celastrol (1 mg/kg) was approximately 1332 cells/mm2, or 40.8% of that of the Celastrol/Control group. In retinas of the Vehicle/ONC group about 381 RGCs/mm2 were counted, which is 9.6% of the total number of RGCs in the DMSO/Control group. This corresponds to approximately a 250% increase in RGC survival mediated by celastrol treatment compared to control. Furthermore, the average RGC number in retinas of ONC animals treated with a single intravitreal injection of 1 mg/kg or 5 mg/kg of celastrol was increased by approximately 80% (760 RGCs/ mm2) and 78% (753 RGCs/mm2), respectively, compared to controls (422 cells/mm2). Injection of 0.2 mg/kg of celastrol had no significant effect on cell survival compared to DMSO-injected controls, with the average number of RGCs being 514 cells/mm2 in celastrol-treated animals versus 422 cells/mm2 in controls. The expression levels of Hsp70, Hsf1, Hsf2, HO-1 and TNF-alpha in the retina were analyzed to evaluate the roles of these proteins in the celastrol-mediated protection of injured RGCs. No statistically significant change in HO-1, Hsf1 and Hsp70 levels was seen in animals with ONC. An approximately 2 fold increase in Hsf2 level was observed in celastrol-treated animals with or without injury. Hsf2 level was also increased 1.8 fold in DMSO-treated animals with ONC injury compared to DMSO-treated animals with no injury suggesting that Hsf2 induction has an injury-induced component. Expression of TNF-alpha in retinas of celastrol-treated uninjured and ONC animals was reduced by approximately 2 and 1.5 fold compared to vehicle treated animals, respectively. The observed results point to the role of TNF-alpha in RGC degeneration following axonal injury, and that suggests mechanisms underlying celastrol’s RGC protective effect is associated with inhibition of TNF-alpha-mediated cell death.

The presence of DH is associated with a greater fast component rate of VF decay. The identification and monitoring of the fast component of VF decay may prove useful in the identification and management of glaucoma patients at high risk of progression.

AIM: To evaluate the therapeutic efficacy, safety and tolerability of newly developed preservative-free (PF) latanoprost generic [TJO-002] and compare it with benzalkonium chloride (BAK)-preserved latanoprost [Xalatan®] in patients with primary open angle glaucoma (POAG) and ocular hypertension (OHT). METHODS: Included patients were aged ≥19y with POAG/OHT. After a washout period, patients with IOP 21-35 mm Hg at 9 a.m. were enrolled. After a full ophthalmic and glaucoma examination, 144 patients with POAG and OHT participated in this study. Subjects were randomly assigned either PF latanoprost (74 eyes) or BAK-preserved latanoprost (70 eyes). All subjects were examined at 4, 8, and 12wk after first administration. At each follow-up visit, IOP was measured at 9 a.m. and 5 p.m. and compliance was assessed. Throughout the study, all adverse events were recorded and monitored by the masked investigators who measured IOP. RESULTS: Both groups showed a statistically significant decrease of average diurnal IOP at 12wk compared to baseline (-7.21±3.10 mm Hg in the PF latanoprost group and -7.02±3.17 mm Hg in the BAK latanoprost group, both P<0.0001). There was no statistically significant diurnal IOP variation between the groups. In terms of tolerability, pruritus, burning/stinging, and sticky eye sensation, severity was significantly lower in the PF latanoprost group than in the BAK latanoprost group (P<0.05). CONCLUSION: PF latanoprost has at least similar efficacy in terms of IOP reduction and better tolerability compared with BAK latanoprost.

Purpose:To evaluate rotational stability of Toric Implantable Collamer Lens (ICL) implantation to correct myopic astigmatism. Methods: We estimated the degree of Toric ICL rotation together with change in visual acuity and astigmatism in 118 eyes of 66 patients who underwent Toric ICL implantation and had a long-term mean follow-up period of 37 months. Results: After Toric ICL implantation, 107 (91%) out of 118 eyes showed uncorrected visual acuity of 0.8 or better. The mean postoperative astigmatism decreased to -0.64 ± 0.61 D from a mean preoperative astigmatism of -2.96 ± 1.13 D. The mean axis change of Toric ICL was 2.4 ± 3.8 degrees during follow-up period. Two (1.7%) out of 118 eyes showed the axis change of more than 10 degrees. These two eyes had a decrease in visual acuity, rotational axis change of 18 degrees and 30 degrees, respectively, and increases in astigmatism of 1.50 D and 1.00 D, respectively. The remaining 116 eyes (98.3%) showed excellent rotational stability without visual acuity decreasing Toric ICL rotation during the follow-up period. Conclusions: Toric ICL implantation to correct high myopia with astigmatism rarely has axis rotation and maintains excellent rotational stability for long-term follow-up.