Activated retinitis pigmentosa peripheral lymphocytes adhere to and alter cultured human retinal pigment epithelial cells.

Interleukin-2 receptor (IL-2R) is an activation molecule that, when expressed on peripheral blood lymphocyte (PBL) membranes, indicates the secretion of IL-2 and initiation of an immune system activation cascade. Comparing the average of IL-2R expression in 34 patients with retinitis pigmentosa (RP) syndrome (561 +/- 282 cells/mm3; mean +/- standard deviation) with 35 age-matched normal subjects (194 +/- 39 cells/mm3), it was found that those with RP had greater numbers of IL-2R-positive cells (P less than 0.001). The increased amounts of IL-2R on PBL of 29 RP and the homotypic self-aggregation of RP PBL by phase and scanning electron microscopy led to the study of the interaction of RP PBL with cultured human postmortem retinal pigment epithelial cells (RPE). A direct correlation was found between the amount of IL-2R expression and the numbers of RP lymphocytes adhering to RPE monolayers. However, the adherence effect was not unique to RP syndrome but appeared to be a nonspecific result of lymphocyte activation. Greater adherence to RPE than normal also was observed in PBL from disease control subjects with elevated IL-2R values and in PBL stimulated by the mitogen, concanavalin A (Con-A). In addition, RPE monolayers were destroyed by Con-A-stimulated PBL that showed 95-98% IL-2R expression. Similar, but less serious effects, occurring in RPE cells after 1 wk's cocultivation with RP PBL, suggested that activated RP lymphocytes can be cytotoxic to RPE during prolonged contact. Because macrophage-like cells and class II major histocompatibility complex expression have been found in RP-affected retinas, immune-mediated cytopathologic effects may contribute to retinal degeneration in RP.

Lack of positive effect of intravitreal bevacizumab in central serous chorioretinopathy: meta-analysis and review.

PURPOSE: To review and evaluate the effects of intravitreal bevacizumab injection (IVB) in centralserous chorioretinopathy (CSC) by meta-analysis. PATIENTS AND METHODS: Clinical controlled studies that evaluated the effect of IVB in CSC were identified through systematic searches of Embase, PubMed, and the Cochrane Central Register of Controlled Trials. Data on the best-corrected visual acuity (BCVA) in logMAR and central macular thickness (CMT) in µm at baseline and 6 months after IVB were extracted and compared with those treated by simple observation. RESULTS: Four clinical controlled studies were included in the meta-analysis. The IVB injection group achieved better BCVA at a follow-up of 6 months. However, the analysis showed that there were no significant differences of BCVA at 6 months after injection between IVB group and the observation group (-0.02 logMAR, 95% CI -0.14 to 0.11, P=0.80). The analysis of the reduction in CMT revealed that the difference between groups was not statistically significant (-8.37 µm, 95% CI -97.26 to 80.52, P=0.85). No report assessed severe complications or side effects of IVB in patients with CSC. CONCLUSIONS: Meta-analysis failed to verify the positive effect of IVB in CSC based on the epidemiological literature published to date.

Comparison of the topographic ablation zone after photorefractive keratectomy for myopia using two different excimer lasers.

PURPOSE: To compare the topographic features of eyes treated with photorefractive keratectomy (PRK) for myopia using two different excimer lasers. METHODS: A total of 65 eyes in 39 patients treated with PRK (6.0-mm optical zone) using Technolas 217C and VISX S4 excimer lasers were evaluated retrospectively to determine the size of the topographic ablation zone. RESULTS: The zones ablated using the VISX S4 had shorter diameters in both axes (-0.89+/-0.73, -1.59+/-0.49 mm; both P=0.00), whereas those ablated using the Technolas 217C had a longer diameter in the major axis (0.96+/-0.63 mm; P=0.00) and a shorter diameter in the minor axis (-0.39+/-0.59 mm; P=0.00). The theoretical ablated zone was a circle with a diameter of 6.0 mm. The Technolas 217C group tended to have oval cuts in comparison with the VISX S4 group, and the difference between the programmed (6.0 mm) and topographic diameters was significant in both groups. CONCLUSIONS: There was a difference between the programmed and postoperative topographic diameters of the ablation zone. The postoperative ablation zone differed in shape and size according to the type of excimer laser.

Blood pressure changes after intravitreal bevacizumab in patients grouped by ocular pathology.

PURPOSE: We evaluated the effects of intravitreal injection of bevacizumab (Avastin; Novartis, Basel, Switzerland) on blood pressure (BP) in the context of ocular vascular pathology. METHODS: This study retrospectively examined 135 consecutive patients treated with intravitreal injections of 1.25 mg bevacizumab for retinal vascular disease; there were 61 cases of diabetic retinopathy, 30 of retinal vein occlusion, 35 of choroidal neo-vascularization (CNV), and 9 of other retinal vascular diseases. BP was measured before injection and at 30 min, 1 day, 1 week, 3 weeks, and thereafter monthly over a 6-month period. RESULTS: In the CNV group, 30-min post-injection systolic values were significantly higher than baseline, and systolic and diastolic values after 1 day, 1 week, and 3 weeks were significantly lower than before injection. No other pressure measurement differed significantly from baseline values in the other groups. DISCUSSION: Intravitreal bevacizumab injection is safe in terms of its effect on BP, regardless of ocular pathology.

Altered membrane fatty acids of cultured human retinal pigment epithelium persistently infected with rubella virus may affect secondary cellular function.

Persistent infection with rubella virus (RV) can alter secondary functions of host cells. Previously we had documented defective phagocytosis of latex beads by cultured human retinal pigment epithelial cells (RPE), persistently infected with M-33 RV (RPE/RV). Here, examining possible mechanisms for altered function, we reported significant differences between the total esterified fatty acids (FA) of RPE and RPE/RV membranes, measured by gas liquid chromatography. RPE/RV contained an increased proportion of saturated FA, particularly palmitic acid, with a presence of unusual chromatographic FA peaks co-eluting with odd-numbered long-chain carbon atom FA not normally found in human cells. Apical membrane microvilli, structures essential to phagocytic activity of RPE and RPE/RV, observed by scanning and transmission electron microscopy, were similar in number and appearance between uninfected RPE and RPE/RV cells before and after latex bead addition. However, RPE/RV microvilli, possibly reflecting altered membrane FA composition, engaged latex beads less effectively than uninfected RPE microvilli. In addition, microvilli remained abnormally distributed on RPE/RV cell surfaces at 48 h after latex addition. Thus, RV persistent infection may affect the cellular membrane fluidity and functional activity of human cells with increased saturated FA proportions and altered FA components of membrane phospholipids. These changes may participate in the defective phagocytosis of RPE/RV.

Phagocytosis of latex beads is defective in cultured human retinal pigment epithelial cells with persistent rubella virus infection.

Phagocytosis, a secondary function of retinal pigment epithelial (RPE) cells essential to sight, was significantly decreased, when measured with latex beads, during persistent rubella virus (RV) infection of human cultured RPE cells. A target for RV in vivo, RPE cells infected with RV (RPE/RV) ingested fewer fluorescent microspheres (26%) than did uninfected RPE cells (68%) (P < 0.001), as measured by flow cytometry. In RPE/RV cells, with characteristic RPE monolayer appearance and normal growth during subculturing over 6 months, persistent RV infection was shown by specific RV antigen immunofluorescence, by the presence of the RV genome in RPE/RV cell messenger RNA, and by recovery of cell-free RV after cocultivation with Vero cells. The adhesion of latex beads to apical cell surfaces of RPE/RV and uninfected RPE cells appeared similar, as imaged by scanning electron microscopy. Cytoskeletal actin, a component of phagocytosis in RPE, appeared altered in 60 to 75% of RPE/RV cells by antiactin immunofluorescence staining, as previously described in other RV-infected cells, but its role in the disturbed phagocytosis of latex beads was not determined. Persistently RV-infected human RPE is an additional example of RV-associated secondary cellular dysfunction in the absence of cytopathic effects.