Anterior Chamber Angle Neovascularization Research Articles

Benefits of a combined surgical technique for patients with secondary neovascular glaucoma.

Aim: To assess the effectiveness and safety of the proposed surgical technique for treating secondary neovascular glaucoma. Materials and Methods: We examined 28 eyes of 28 patients (16 women and 12 men), aged 46}7,2 years, with secondary neovascular glaucoma. All patients underwent a comprehensive ophthalmological examination before and during treatment. Two-stage treatment was applied to all patients. At the first stage - performed an advanced technique of non-penetrating deep sclerectomy while administering anti-VEGF (anti-vascular endothelial growth factor) intravitreal or intracameral injections. At the second - we performed externalization of Schlemm's canal followed by YAG laser trabeculectomy. Statistical analysis of the results was used the SPSS v. 11.0, MedStat v.15.1 software package for medical and biological research. Results: The proposed surgical technique, leads to a gradual decrease in intraocular pressure (IOP) and regression of the iris and anterior chamber angle neovascularization. The postoperative course was uneventful for all the patients. In the early postoperative period, the IOP was observed to be normalized in all the eyes. The IOP ranged from 12 to 16 mm Hg. The neovascularization regression occurred (in 100 % of cases) within 5-7 days. Conclusions: Gradual reduction of IOP reduces intraoperative complications. Intravitreal or intracameral injections of anti-proliferative agents contribute to the regression of neovascularization and further gradual reduction of IOP. Performing a laser trabeculectomy in the area where a non-penetrating deep sclerectomy was previously performed creates new pathways for the outflow of intraocular fluid from the anterior chamber and reduces the risks of reintervention.

Clinical and morphological aspects of the development of secondary ophthalmic hypertension in uveal melanoma

Ophthalmic hypertension is mostly associated with medium- or large-sized melanomas. The pathogenesis of persistent IOP elevation in uveal melanoma is not fully understood at present. Purpose. To analyze the clinical and morphological mechanisms of the development of secondary ophthalmic hypertension in patients with uveal melanoma. Material and methods. The case histories of 26 patients with T3N0M0-T4N0M0 uveal melanoma were analyzed retrospectively from 2015 to 2019. The main group included 18 patients with secondary monolateral IOP elevation while the control group was composed of 8 patients with normal IOP. Tumors in both groups were comparable in size. All patients underwent eradication treatment (enucleation/exenteration). Enucleated eys were histologically examined. Results. Pronounced pathological changes of the iridocorneal angle, iris and ciliary body were found morphologically in all specimens with elevated IOP. The following dominating mechanisms ofophthalmic hypertension were detected: iris and anterior chamber angle neovascularization; tumor-associated chronic uveitis; obstruction of trabecular meshwork by cellular elements (pigment-rich macrophages, blood cells, inflammatory cells); fibrosis and deformation of trabecular meshwork and Schlemm's canal; closed angle glaucoma with lens-iris diaphragm shift; tumor invasion into the angle. Conclusions. Investigation of morphological changes in patients with UM and found resemblances with already studied non-tumor forms of glaucoma may help find previously undetectable receptors for the development of targeted anti-tumor drugs.

Etiology, pathogenesis, and diagnosis of neovascular glaucoma.

Neovascular glaucoma is defined as iris and/or anterior chamber angle neovascularization associated with increased intraocular pressure. It is a secondary glaucoma that is most frequently caused by severe retinal ischemia. The most common diseases responsible for the development of neovascular glaucoma are diabetic retinopathy, ischemic central retinal vein occlusion, and ocular ischemic syndrome. Uncommon causes include ocular radiation, ocular tumors, uveitis and other miscellaneous conditions. Vascular endothelial growth factor is an important and likely predominant agent involved in the pathogenesis of intraocular neovascularization and neovascular glaucoma. The evolution of clinical and histopathological changes from predisposing conditions to the occurrence of rubeosis iridis and neovascular glaucoma is divided into four stages: prerubeosis, preglaucoma, open angle glaucoma, and angle-closure glaucoma.

VEGF inhibitors in glaucoma surgery

Vascular endothelial growth factor (VEGF) is a signaling protein, that controls vasculogenesis, angiogenesis, vascular support and stimulates permeability of small blood vessels. The following isoforms are presently known: VEGF-A, VEGF-B, VEGF-C, VEGF-В and PGF. VEGF-A, that regulates neoangiogenesis and fibroblast formation, is thought to play the most important role in human organism. Increased expression of VEGF may lead to development and aggravation of pathological conditions including oncology. The article presents a review of preclinical and clinical studies of the main VEGF-inhibitors - bevacizumab and ranibizumab, as well as a brief account on other existing medications of this group. It describes ophthalmological indications for the use of antiangiogenetic agents, as well as the ways of their possible off-label use. The review presents investigations of intravitreal and intracameral injections of VEGF-inhibitors in patients with retinal, chorioidal, iris, and anterior chamber angle neovascularization. It gives examples of successful anti-VEGF use before Ahmed glaucoma valve drainage device implantation and in cases of neovascular glaucoma, induced by radiation therapy for intraocular tumors. Tenon’s capsule’s fibroblasts take part in the process of postoperative wound healing and scarring. According to the latest research, this process could be modulated by angiogenesis inhibitors. This review also recounts the use of anti-angiogenic agents to inhibit postoperative fibroblast proliferation, when used as monotherapy, or as an adjuvant to mitomycin С or 5-fluorouracil. It reviews the research on VEGF-inibitors use in combination with postoperative needling.

Bevacizumab (Avastin®) for the management of anterior chamber neovascularization and neovascular glaucoma

To establish the efficacy and safety of intravitreal bevacizumab in reducing iris and anterior chamber angle neovascularization and managing neovascular glaucoma. Prospective interventional case series. Eleven eyes of 11 patients with iris and anterior chamber angle neovascularization with refractory intraocular pressure were treated with intravitreal injection of 1.25 mg bevacizumab (Avastin((R))). The study group included eight males and three females aged 23 to 77 years (average, 62 years). Out of the 11 cases, five had proliferative diabetic retinopathy, of whom two had undergone vitrectomy for tractional retinal detachment and vitreous hemorrhage, and six were secondary to ischemic central retinal vein occlusion (CRVO). All patients were followed for eight to 16 months (average, 10 months). Iris and anterior chamber angle neovascularization receded in all eyes after one to three injections at monthly intervals. In five eyes, neovascularization recurred during the follow-up period. The intraocular pressure normalized in one eye. Four eyes were controlled with anti-glaucoma drops. A cyclodestructive procedure was required in two eyes. An Ahmet drainage valve was implanted in four eyes, including one controlled with additional antiglaucoma drops and one in which the intraocular pressure remained high while on maximum antiglaucoma medication and a cyclodestructive procedure was scheduled. Bevacizumab appears to be effective in reducing iris and anterior chamber angle neovascularization and is likely to extend our therapeutic options in the management of neovascular glaucoma.

Intravitreal Bevacizumab for the Treatment of Neovascular Glaucoma Associated With Central Retinal Artery Occlusion

We report three cases of neovascular glaucoma secondary to central retinal artery occlusion (CRAO) which were effectively managed with intravitreal bevacizumab (IVB) followed by panretinal photocoagulation (PRP). Neovascular glaucoma without peripheral anterior synechiae developed between one and five weeks following CRAO onset. All patients received 0.75 mg (0.03 ml) IVB. In all patients, complete regression of the iris and anterior chamber angle neovascularization was confirmed within one week. PRP was applied two weeks after the injection. The follow-up period was four to seven months (average, five months). Intraocular pressure was controlled in all patients using topical antiglaucoma medications alone. However, one patient experienced a recurrence of neovascularization three months after the initial combination treatment. This patient received another IVB injection and additional PRP, and the recurrent neovascularization resolved. There were no local or systemic adverse events in any patients. Therefore, intravitreal bevacizumab may be an effective adjunct in the treatment of neovascular glaucoma associated with CRAO.

Role of Intravitreal Bevacizumab in Neovascular Glaucoma

We report on the effect of intravitreal bevacizumab (IVB) for the treatment of neovascular glaucoma (NVG). A retrospective chart review of 6 consecutive cases of NVG was performed. The follow-up period was 3-19 months (average, 9.7 months). All patients received 1.25 mg (0.05 cc) of IVB followed by panretinal photocoagulation (PRP) approximately 1 week later. In all cases, there was a complete regression of iris and anterior chamber angle neovascularization. However, 2 eyes showed a recurrence of neovascularization; in 1 case, it recurred after 3 months, and in the second, after 5 months. These patients received another IVB injection followed by additional PRP, which resulted in the resolution of the recurrent neovascularization. Glaucoma was controlled with topical eye drops alone in patients who had iris and angle neovascularization without peripheral anterior synechiae (PAS). However, patients with PAS at the time of presentation needed subsequent glaucoma surgery. Our study suggests that IVB may be a valuable addition in the treatment of NVG by hastening the resolution of anterior segment neovascularization, improving the results of glaucoma surgeries, and appears to give long-term control when used in combination with PRP.

Iris and anterior chamber angle neovascularization after iodine 125 brachytherapy for uveal melanoma

Iris neovascularization (INV) and anterior chamber angle neovascularization after radiotherapy for uveal melanoma may lead to neovascular glaucoma and enucleation. However, neovascularization of the anterior ocular segment may respond favorably to treatment with panretinal photocoagulation. The purpose of this study was to evaluate the frequency, interval to development, and predisposing factors of anterior ocular segment neovascularization following iodine 125 (I125) brachytherapy for uveal melanoma. Retrospective, interventional, consecutive case series. Sixty-five patients (65 eyes), consecutively treated with I125 brachytherapy for uveal melanoma from 1995 through 2000 and followed up after radiation therapy for 24 months or more. Clinical findings and ultrasonography characteristics as well as treatment parameters were analyzed. The frequency of INV was determined and the interval to development of INV as well as the predisposing factors were analyzed statistically. In 15 of 65 eyes (23%), INV was detected after I125 brachytherapy at a mean +/- standard deviation of 26.66+/-11.63 months (median, 24 months; range, 9-48 months). Risk factors displaying the stronger correlation with INV were greater maximal tumor height (P<0.01), greater tumor vascularity (P<0.01), and disinsertion of horizontal rectus muscles (P = 0.01). After I125 brachytherapy for choroidal melanoma, INV developed in 23% of eyes and was correlated with larger tumor size, greater tumor vascularity, and disinsertion of a horizontal rectus muscle.

The Treatment of Angle Neovascularization with Panretinal Photocoagulation

Thirty-two eyes in 28 patients with anterior chamber angle neovascularization were prospectively treated with panretinal photocoagulation. Of 17 eyes that had less than 270 degrees angle closure, with an intraocular pressure of less than 40 mm Hg prior to treatment, 16 showed complete disappearance of the angle neovascularization and stabilization of the peripheral anterior synechiae after treatment. None of the 15 patients who had angle closure of 270 degrees or greater, or an intraocular pressure of above 40 mm Hg, showed any significant improvement after treatment. These results suggest that panretinal photocoagulation offers a highly effective means of dealing with early and moderately advanced cases of angle neovascularization.