Rosiglitazone inhibits TGF-ß 1 induced activation of human Tenon fibroblasts via p38 signal pathway.

PURPOSE: Transdifferentiation of human Tenon fibroblasts to myofibroblasts and subsequent deposition of extracellular matrix is a key step in the scarring after glaucoma filtration surgery. The p38 signaling pathway plays an important role in cell proliferation and differentiation, and its upstream regulators and downstream molecules are widely distributed in the eye. We aimed to investigate the role of p38 in the activation of Tenon fibroblasts and that of the anti-fibrotic mechanism of rosiglitazone in the modulation of the p38 signaling pathway. METHODS: Cultured Tenon fibroblasts were stimulated with transforming growth factor (TGF)-ß1. Activation of p38 was examined by western blot analysis. Rosiglitazone and blocking of the p38 signaling pathway by SB203580 were used to antagonize stimulation by TGF-ß1. Fibroblast motility was examined by wound closure assay; alpha-smooth muscle actin, connective tissue growth factor, and collagen type I were determined by qPCR and western blot. Expression and localization of alpha-smooth muscle actin were determined by immunofluorescence staining. RESULTS: Phosphorylated p38 was upregulated in fibroblasts stimulated with TGF-ß1, and this effect was substantially inhibited by rosiglitazone. Proliferation and migration of fibroblasts were suppressed by rosiglitazone and SB203580. Expression of alpha-smooth muscle actin, connective tissue growth factor, and collagen type I were decreased at the mRNA and protein levels by rosiglitazone and SB203580. However, the inhibitory effect of SB203580 on transcription and protein expression was weaker than that of rosiglitazone. Similar phenomena were found on immunofluorescence microscopy of alpha-smooth muscle actin. CONCLUSIONS: The p38 signaling pathway mediates the TGF-ß1-induced transdifferentiation of human Tenon fibroblasts to myofibroblasts. Rosiglitazone can exert anti-fibrotic activity by interfering with the TGF-ß/p38 signaling pathway and might be useful for modulating scar formation after glaucoma filtration surgery.

Episcleral macular buckling for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole.

AIM: To evaluate anatomical and visual outcomes of episcleral macular buckling (EMB) for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole. METHODS: Five cases of EMB for initial failure of retinal reattachment after internal limiting membrane (ILM) peeling and silicone oil tamponade caused by myopic macular hole were retrospectively reviewed. A silicone sponge sutured directly across the macular region was performed on the silicone oil filled eyes. Silicone oil was removed no sooner than 1 month post-EMB. The duration of follow-up time after removal of silicone oil was more than 3 months. RESULTS: Retinas of five eyes were all reattached at the last follow-up. The postoperative vision ranged from counting fingers to 0.08. CONCLUSION: Anatomical results improved after EBM for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole, which was not evident for visual outcome.

Efficacy and necessity of prophylactic vitrectomy for acute retinal necrosis syndrome.

AIM: To compare the efficacy of prophylactic vitrectomy for acute retinal necrosis syndrome(ARN) with routine treatment in Chinese patients, thereby investigate the necessity of prophylactic vitrectomy for ARN. METHODS: Thirty patients (37 eyes) were retrospectively included in this study. The eyes were divided into 2 groups by treatment, including routine treatment, which consisted of antiviral medication and vitrectomy after retinal detachment (RD) (n=21), and prophylactic vitrectomy, which consisted of antiviral medication and vitrectomy for the prevention of RD performed during the active inflammatory phase (n=16). The extent of necrosis was determined by fundus photographs at the time of presentation (for eyes with mild vitreous opacity) or the drawings in the operation records. Necrosis of the 37 eyes was divided into 3 grades, including peripheral, middle-peripheral and extensive. The follow-up period ranged from 8 to 57 months. Differences in visual acuity and necrosis between groups were identified using independent samples t-test. RESULTS: Necrosis was more extensive in the routine treatment group than in the prophylactic vitrectomy group (P<0.05). In the routine treatment group, conservative treatment improved necrosis and prevented RD in 6 eyes (29%). Seven eyes (33%) obtained anatomical success, but retinal redetachment occurred in 8 eyes (57%). There were also 5 eyes (24%) developed ocular hypotony or atrophy. Ten eyes (48%) achieved equal or increased visual acuity. In the prophylactic vitrectomy group, RD occurred in 2 eyes (13%). Twelve eyes (75%) were completely anatomically successful, and 10 eyes underwent silicone oil removal. Only one eye (6%) became ocular hypotony. Fourteen eyes (88%) achieved equal or increased visual acuity. The prophylactic vitrectomy group achieved better vision trends than the routine treatment group (P<0.05). Eyes with peripheral necrosis had better visual outcomes than those with mid-peripheral (P<0.05) or extensive (P<0.05) necrosis. However, there was no significant difference between eyes with mid-peripheral and extensive necrosis (P=0.3008) CONCLUSION: Prophylactic vitrectomy can prevent RD and improve the prognosis of ARN, making it an option for cases with rapidly progressing necrosis despite antiviral treatment and cases with moderate to extensive necrosis and severe vitreous opacity.

Repeatability and agreement of CCT measurement in myopia using entacam and ultrasound pachymetry.

AIM: To evaluate the repeatability of central corneal thickness (CCT) measurement by entacam, and agreement of CCT measured by Pentacam and ultrasound pachymetry (USP) in Chinese myopia. Thereby investigate the possibility of Pentacam as a substitute for USP in CCT measurement before refractive surgery. The effects of corneal curvature measured by Pentacam on CCT were also evaluated. METHODS: One hundred and forty-eight right eyes of 148 individual with myopia were included in this study. Three successive Pentacam CCT measurements followed by 10 successive ultrasound pachymetry were carried out in the 148 eyes. Mean of CCT taken by each device was calculated for comparison. According to the CCT measured by USP, all the 148 eyes were divided into 3 groups: <520µm, 520-560µm, >560µm. For all eyes and each group the CCT obtained by Pentacam and USP were compared. Anterior corneal curvature of the 148 eyes was also adopted for correlation analysis with CCT obtained by ultrasound pachymetry. In addition, CCT measurement using 60 random selected Scheimpflug images was performed by 3 skilled investigators at different time, and this was repeated for 3 times by a forth investigator to assess repeatability of Pentacam CCT measurement using Scheimpflug images. RESULTS: Intraclass correlation coefficient (ICC) analysis revealed high intraobserver repeatability (ICC=0.994, F=158.60, P<0.001) for CCT measurement by Pentacam. The interobserver (ICC=0.998, F=494.73, P<0.001) and intraobserver (ICC=0.997, F=383.98, P<0.001) repeatability for Pentacam CCT measurements using Scheimpflug images were also excellent. There was high positive correlation between the CCT values measured by Pentacam and ultrasound pachymetry (r=0.963, P<0.001). Bland-altman plots showed that the Pentacam underestimate the CCT by 8.02µm compared with ultrasouond pachymetry. The differences between Pentacam and USP increased as the CCT readings by USP increased (Pentacam vs USP: slope=-0.04, P<0.05). The 95% upper and lower limits of agreement between CCT values obtained from the two devices were +9.33µm and -25.37µm. No significant association could be found between CCT and anterior corneal curvature. CONCLUSION: Inter- and intraobserver variability for CCT measurements by Pentacam was considerably below clinically significant levels. CCT of myopia obtained by Scheimpflug camera, Pentacam, were highly correlated to that by ultrasound pachymetry. However, the values obtained are not directly interchangeable between Pentacam and ultrasound pachymetry as the 95% limits of agreement are relatively wide. Pentacam can be a useful instrument for measuring CCT in candidates to refractive surgery in clinic.

Effect of Bak Foong Pills on the expression of ß-amyloid in rat retina with optic nerve transection.

AIM: To investigate the effect of Bak Foong Pills (BFP) on the expression of ß-amyloid (Aß) in rats retina with optic nerve transection, and its roles and possible mechanisms in protecting optic nerve damage. METHODS: Seventy-two healthy, Sprague-Dawley, adult rats were randomly assigned to three groups: negative control group (control group), optic nerve transection group (model group) and BFP treatment group (BFP group, 100µg/mL) followed by establishing optic nerve transection model. The expression of Aß was measured at 48 hours by Western-blotting. Moreover, the expressions of Bcl-2, Bax and Caspase-3 mRNA were evaluated at 48 hours by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: There were significant differences among the control, model and BFP groups in the expression of Aß (all P<0.01). Aß expression was significantly higher in the model and BFP groups than that in the control group (P<0.01), with a more significant reduction in the BFP group than that in the model group (P<0.01). Moreover, there were also significant differences among the three groups in the expressions of Bcl-2/Bax (Bcl-2: anti-apoptotic; Bax: proapoptotic) and Caspase-3 mRNA (proapoptotic) (all P<0.01). Bcl-2/Bax ratio was significantly lower and Caspase-3 mRNA expression was significantly higher in the model and BFP groups than those in the control group (P<0.01), with a significant growing of Bcl-2/Bax and reduction of Caspase-3 in the BFP group than those in the model group (P<0.01). CONCLUSION: BFP can down-regulate Aß expression in retina and may inhibit apoptosis and protect optic nerve by enhancing Bcl-2/Bax ratio and inhibiting Caspase-3 pathway.

[Treatment of patients with rhegmatogenous retina detachment combined with non-secondary glaucoma].

OBJECTIVE: To discuss the cause of disease, treatment and therapeutic effect in patients with rhegmatogenous retina detachment (RRD) combined with non-secondary glaucoma. METHODS: Clinical data of 28 patients with RRD combined with primary or congenital glaucoma were retrospectively analyzed. RESULTS: Twenty-five out of the 28 patients succeeded with one operation (89.3%). The intraocular pressure of post-operation:on the 1st day was 10 approximately 46 (28.1+/-6.5) mmHg, on the 7th day was (18.9+/-7.2) mmHg, and on the last re-examination day was (17.6+/-6.2) mmHg. Anti-glaucoma operation was performed in 10 patients after the retinal operation. Chroidal hemorrhage was found in 2 patients and 2 chroidal exudations were found after the retinal operation. CONCLUSION: The proportion of primary open angle glaucoma is higher than that of primary angle closure glaucoma, and trauma or surgery before the retinal operation is an important cause in glaucoma patients with RRD. There is no obvious difference in the ratio of surgical success between non-secondary glaucoma with RRD and those RRD patients without glaucoma. Vitreotomy+ silicon oil injection or drainage of subretinal fluid+air injection+cryocoagulation+explants is recommended. Chroid is easily involved. It is important to control the intraocular pressure during and after the surgery. The final visual acuity is rather poor, which may be related to the glaucoma and intraocular pressure.

[Clinical observation on argon green laser in the treatment of diabetic macular edema].

OBJECTIVE: To assess the clinical effect of argon green laser photocoagulation on diabetic macular edema. METHODS: Grid macular photocoagulation with argon green laser (lambda = 514 nm), 100-200 microns spot diameter and 0.1-0.2 s duration, was applied to 23 eyes of diabetic macular edema. Panretinal scatter photocoagulations, if needed, were carried out in the later therapy. The mean of the follow-up period was (9.3 +/- 4.1) months. Changes in macular edema and visual acuity as well were observed. RESULTS: Complete and partial resolution of macular edema occurred in 21 out of the 23 eyes and visual acuity improved or remained unchanged in 19 out of the 23 eyes. CONCLUSION: Grid macular photocoagulation with argon green laser is effective and relatively safe in the treatment of diabetic macular edema.