The Inhibitory Effect of Connective Tissue Growth Factor Antibody on Postoperative Fibrosis in a Rabbit Model of Trabeculectomy.

Purpose: To compare the efficacy of subconjunctival injection of an anti-connective tissue growth factor antibody (anti-CTGF) versus mitomycin-C (MMC) and placebo in reducing scar formation in a rabbit model of trabeculectomy. Methods: A total of 14 rabbits were included. Nine rabbits underwent trabeculectomy with subconjunctival injections of either anti-CTGF antibody, MMC, or balanced salt solution (BSS), each administered in three eyes, before peritomy. The anti-CTGF group received a repeated dose of the antibody five days after surgery. All nine rabbits were euthanized on day 14; the globes were stained with hematoxylin & eosin, Masson's Trichrome, and immunohistochemistry for detecting alpha-smooth muscle (α-SMA) actin. RNA extraction was performed on five eyes of the remaining rabbits which included one eye without any surgery, one eye 5 hr after trabeculectomy without any injection, one eye five days after trabeculectomy without any injection, and two eyes five days after trabeculectomy with administration of MMC and BSS, respectively. Results: The mean bleb area in the anti-CTGF, MMC, and control groups was 3.8 ± 1.45, 5.9 ± 1.4, and 3.5 ± 1.9 mm2, respectively. Collagenous tissue was found to occupy the bleb area by 13.7%, 13.5%, and 18.5%, respectively. This ratio was significantly higher in the BSS group (P = 0.04). The expression of CTGF mRNA after 5 hr and five days in eyes undergoing trabeculectomy were significantly more pronounced as compared to the unoperated eye. The mean H-SCORE of α-SMA-immune reactive cells calculated as the grade of staining multiplied by the percentage of immune stained cells was 14.6, 10.22, and 140.58 in the anti-CTGF, MMC, and control groups, respectively. While the control eyes had a significantly higher score (Ps < 0.001), the anti-CTGF and MMC groups were comparable (P = 0.87). Conclusion: Based on the results of this animal study, the anti-CTGF antibody injection resulted in a significant reduction in collagenous tissue and myofibroblast cells after trabeculectomy.

The Influence of Near Vision Tasks on Intraocular Pressure in Normal Subjects and Glaucoma Patients.

Purpose: To investigate the effect of static accommodative tasks on intraocular pressure (IOP) of glaucomatous and normal eyes. Methods: Four groups of subjects categorized as primary open-angle glaucoma (POAG), primary angle-closure suspects (PACS), normal age-matched controls, and normal young adults (NYA; age < 40 years) were enrolled. The baseline IOPs were measured after the subjects were looking at a distant target for 15 min. Static accommodation was obtained by execution of near vision tasks (reading at 33 cm in daylight [300 lux] for 60 min). IOPs were measured at 15, 30, 45, and 60 min intervals while accommodating and then measured again after 15 min of relaxing accommodation while looking at a distant target. Results: One-hundred and eighteen eyes of 98 subjects were recruited. The study groups consisted of the following categories: 25 POAG (46 eyes), 24 PACS (47 eyes), 25 matched controls (50 eyes), and 24 NYA (48 eyes). Within all groups, the mean IOP decreased throughout the accommodation period at all time points. Maximum IOP reduction after accommodation was detected at the 30-min time among the POAG subjects, at the 45-min time in the PACS and matched control groups, and at 15 min after the relaxation of accommodation in the NYA group. IOP reduction levels showed no statistically significant difference among POAG, PACS, and the normal matched groups in their response to accommodation. However, NYA had significantly lower IOP and greater IOP reduction after the resting period (relaxation of accommodation). Conclusion: Static accommodative tasks can significantly reduce IOP in normal, POAG, and PACS individuals. Encouraging glaucoma patients to practice periodical near vision tasks could be viewed as an adjunctive measure for glaucoma management.

A new glaucoma drainage implant with the use of Polytetrafluoroethylene (PTFE). A pilot study.

Purpose: To investigate the implantation of Polytetrafluoroethylene (PTFE) as a glaucoma drainage device. Methods: This study has been done in two steps. First, the constructed implants have been used in 4 rabbits and the histopathologic response was evaluated. In the second step, the implants were used in the 6 eyes of 6 patients with end-stage glaucoma with uncontrolled IOP and poor visual acuity. The tube was made of two-layer of PTFE membrane measuring 8 * 6 mm with a thickness of 1.8 mm and a silicone tube. The rabbits and the human eyes underwent surgical implantation of the tube in the anterior chamber. The histopathologic evaluation was done using H&E staining. Visual acuity, intraocular pressure and the number of glaucoma medications were assessed before and after the surgery. Results: In the histopathologic evaluation, subconjunctival polarizing fibers of a synthetic mesh infiltrated by fibrovascular septa was seen. A granulomatous inflammatory reaction composed of histiocytes, lymphocytes, and multinucleated giant cells were seen around and between the synthetic bundles. The average age of patients was 63 ± 5.5 years. The mean IOP reached from 36.6 ± 5.7 mmHg at baseline to 16.2 ± 8.9 mmHg at the final follow-up. Patients were followed for an average of 6.6 ± 4.5 months. One patient found hypotony refractory to medical and surgical treatment, which led to implant removal. One patient had uncontrolled IOP and finally led to phthisis bulbi following slow CPC. The remaining four eyes did well during the follow-up. Conclusion: The use of PTFE as a new polymer in tube shunt construction was reported. Larger studies, modification of the PTFE membranes like changing the porosity amount, and size of PTFE membranes might result in different conclusions.

Ahmed Glaucoma Valve Implantation: Graft-Free Short Tunnel Small Flap versus Scleral Patch Graft after 1-Year Follow-up: A Randomized Clinical Trial.

PURPOSE: To compare the efficacy and safety of the graft-free short tunnel small flap (STSF) technique with that of the scleral patch graft (SPG) in Ahmed glaucoma valve (AGV) (New World Medical Inc, Rancho Cucamonga, CA) implantation. DESIGN: Randomized clinical trial. PARTICIPANTS: A total of 203 eyes of 203 patients with medically uncontrolled glaucoma, including 102 in the STSF group and 101 in the SPG group. METHODS: Patients were enrolled and assigned randomly to STSF or SPG. MAIN OUTCOME MEASURES: Tube exposure, intraocular pressure (IOP), number of glaucoma medications, best-corrected visual acuity, surgical complications, and success rate (defined as IOP >5 mmHg, ≤21 mmHg, and IOP reduction ≥20% from baseline at 2 consecutive visits after 3 months, no reoperation for glaucoma). RESULTS: Only 1 patient in the SPG group developed tube exposure at 1-year follow-up. The cumulative probability of success during the first year of follow-up was 70% in the STSF group and 65% in the SPG group (P = 0.36). The IOP decreased significantly from 29.6±8.6 mmHg at baseline to 16.4±3.6 mmHg at the final follow-up in the STSF group (P = 0.001). The corresponding numbers for the SPG group were 30.9±11.2 and 15.8±4.7, respectively (P = 0.001). The final IOP was comparable between both groups (P = 0.65). Mean ± standard deviation of the number of glaucoma medications was 1.8±0.9 in the STSF group and 1.6±0.9 in the SPG group at final follow-up (P = 0.32). Postoperative complications developed in 8 patients (19%) in the STSF group and 9 patients (23%) in the SPG group (P = 0.81). CONCLUSIONS: The STSF and SPG techniques had a comparable complication rate at the 1-year follow-up. Both techniques were comparable in terms of success rate, postoperative IOP, and glaucoma medications.