Intravitreal aflibercept for rubeosis iridis secondary to proliferative diabetic retinopathy.

The purpose of this article is to report a case with rubeosis iridis treated by intravitreal aflibercept. A 61-year-old man had iris neovascularization and scanty vitreous hemorrhage secondary to proliferative diabetic retinopathy in the right eye. Neither neovascularization of angle nor elevation of intraocular pressure was found. Single intravitreal aflibercept 2 mg injection was performed. Rubeosis iridis disappeared on the next day. Scattered retinal laser photocoagulation was added 1 week later. There was no recurrence after 3-month follow-up. Aflibercept may serve as another anti-vascular endothelial growth factor (anti-VEGF) for treating rubeosis iridis.

Bilateral spontaneous hyphaema: case report and review of literature.

To report a case of bilateral spontaneous hyphaema in a patient on warfarin sodium for atrial fibrillation and COPD. A case report and literature review. A 76-year-old man presented with bilateral spontaneous hyphaema. There was no anterior chamber pathology known to predispose for spontaneous bleeding except for a history of paroxysmal atrial fibrillation treated with a daily dose of 3 mg of warfarin sodium. In addition, he was also suffering from severe COPD and was on oxygen supplementation. This is a rare case of a bilateral spontaneous hyphaema. Although the patient was on warfarin sodium, his INR was only 2.6 at the onset of his symptoms. It may be possible that the combined action of anti-coagulant properties of warfarin sodium and hypoxic vasodilatation of iris vessels may be responsible for bilateral hyphaema in this case.

[Ultrastructural features of vascular iridociliary system after biopuncture by antihomotoxic medicine].

OBJECTIVE: To reveal ultrastructural features of iridociliary vessels after biopuncture with antihomotoxic medicine. METHODS: Myopia model was created on 10 rabbits by injecting all trans-retinoic acid in catheter Vasofix Certo 24G in left internal carotid artery until we got low myopia. After six months of daily injections all rabbits had myopia from -2,0 to 3,0 D. Animals were separated into two groups: 5 rabbits with daily intradermal injection in three points of upper eye lid without medicine during 10 days and 5 rabbits with daily intradermal injection in three points of upper eye lid with Cerebrum Compositum N during 10 days. Morphology of iridociliary system was explored. RESULTS: Biopuncture in myopia model increases level of metabolic reactions in iridociliary system, supplies adaptive reserves by the hemodynamic enrichment of ciliary body vessels and balance of autonomic nervous system impulsation.

[Study on acting mechanism of shenqi yiqi drop pill for intervening irido-microangiopathy in diabetic rats].

OBJECTIVE: Use laser confocal microscopy overspeed camera technique and fluorescence albumin labeling to study the acting mechanism of Qishen Yiqi Drop Pill (QYDP) for intervening irido-microangiopathy (IMAP) in diabetic rats. METHODS: Rat model of diabetes mellitus type 1 (DM1) was established by intraperitoneal injection of streptozocin (STZ). The model rats were randomly divided into three groups, the treatment group, the model group and the control group. At the same time a normal control group was set up. The treatment group was medicated with QYDP (prepared into liquid form), and the control group with Duobeisi liquor (1 g/kg per day) for 10 months. The dynamic state of iris microcirculation in rats was observed using laser confocal microscopy overspeed camera. RESULTS: Compared with the treatment group, blood flow in iris of model rats was slower significantly (P < 0.01); the fluorescence density and leakage area of inside and outside iris vessels, and the iris vascular diameter were significantly higher in the model group than those in the treatment group (P < 0.01). CONCLUSION: QYDP has definite effect in improving iris microcirculation, which can accelerate the blood flow, inhibit the abnormal expansion of vessels and improve the increased iris micro-vascular permeability.

Long-term effects of oral vitamin C supplementation on the endothelial dysfunction in the iris microvessels of diabetic rats.

The current study was aimed to investigate effects of long-term supplementation of vitamin C on the iris microcirculation in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in male Wistar-Furth rats by intravenous injection of STZ (55 mg/kg b.w.). The rats were divided into three groups: control rats (CON), STZ-induced diabetic rats (STZ), and STZ rats supplemented with vitamin C (STZ-vitC). For supplementation of vitamin C, ascorbic acid (1 g/l) was added into the drinking water. The experiments were performed at different periods (8, 12, 24 and 36 weeks) after injection of STZ. Blood glucose, tissue lipid peroxidation and plasma vitamin C were measured. To examine the endothelial function, leukocyte adhesion to the venular endothelium was evaluated in the iris post-capillaries by means of counting the number of leukocytes labeled with rhodamine 6G. Blood flow perfusion in the iris was monitored using a laser Doppler flow meter. In the STZ rats, hyperglycemia was induced with an increase in HbA(1c) and lipid peroxidation but with a decrease in the plasma vitamin C level which improved by vitamin C supplementation. The number of adherent leukocytes increased significantly, associated with reduction in the iris blood flow perfusion, at 8, 12, 24 and 36 weeks after injection of STZ. In the STZ-vitC rats, the iris blood flow perfusion was significantly increased in comparison with the STZ rats, while the leukocyte adhesion was decreased at 24 and 36 weeks. The statistical analysis shows that the leukocyte adhesion decreased with increase in the iris blood flow perfusion in STZ and STZ-vitC rats. In conclusion, vitamin supplementation suppressed leukocyte adhesion and thus endothelial dysfunction, associated with increase in iris blood flow perfusion in diabetes. The antioxidant vitamin C may be a therapeutic agent for preventing diabetic retinopathy.

Combined effects of curcumin and vitamin C to protect endothelial dysfunction in the iris tissue of STZ-induced diabetic rats.

This study was aimed to evaluate the combined effect of curcumin with vitamin C supplementation on hyperglycemic and dyslipidemia conditions and endothelial cell dysfunction induced in diabetic rats. Wistar Furth rats were used and divided into four groups: control (single injection of 0.9% sterile saline), STZ (streptozotocin, Sigma, 55 mg/kg.BW, i.v.), STZ-vitC (1 g/l ascorbic acid mixed in drinking water), STZ-cur (daily oral treatment of 300 mg/kg.BW curcumin; Cayman Chemical Co., USA), and STZ-cur+vitC (1 g/l ascorbic acid mixed in drinking water and oral treatment of 300 mg/kg.BW curcumin). On 8th week after STZ-injection, the microcirculation in the iris tissue was observed using intravital fluorescence videomicroscopy, and also leukocyte adhesion in the venule was examined for each group. Blood glucose (BG), lipid profiles, glycosylated hemoglobin (HbA1c) were measured in blood samples collected at the end of each experiment. The contents of liver malondialdehyde (MDA) were also quantified for each group. Feeding curcumin (STZ-cur) could decrease BG, HbA1c, dyslipidemia, and MDA significantly, compared to STZ. In cases of feedings curcumin with vitamin C, these results were more effective in all aspects, including leukocyte adhesion. In conclusion, curcumin might increase the effect of vitamin C in protecting the function of endothelial cells through its anti-oxidant with hypoglycemic and hypolipidemic actions.

Anisodamine increases blood flow to the retina-choroid and protects retinal and pancreatic cells against lipid peroxidation.

This study investigated the effect of anisodamine (2 and 5 mg/kg i.v.) on ocular and systemic blood flow distribution in awake lambs using the radioactive microsphere technique. In separate in vitro studies, the effects of anisodamine (at final concentrations of 0.01 to 2.5 mg/ml) were determined on arachidonic acid, alloxan and ultraviolet radiation-induced lipid peroxidation of isolated retinal cells from rabbits and on alloxan-induced lipid peroxidation of hamster pancreatic islet beta cells. Malondialdehyde production was used as an index of lipid peroxidation and measured by the thiobarbituric acid method. Anisodamine preferentially increased blood flow and oxygen delivery to the retina-choroid and iris-ciliary body of the eye by 50-100%. Anisodamine significantly attenuated lipid peroxidation in retinal cells induced by ultraviolet radiation, alloxan and arachidonic acid by 17-50% and protected pancreatic beta cells against alloxan-induced lipid peroxidation. These properties may, in part, account for the beneficial effect of anisodamine in certain patients with diabetes.

Morphology of tight junctions in the ciliary epithelium of rabbits during arachidonic acid-induced breakdown of the blood-aqueous barrier.

A reversible breakdown of the blood-aqueous barrier in the iridial processes of rabbits has been induced by arachidonic acid as demonstrated by the passage of horseradish peroxidase at places through the tight junctions. Freeze-fracture images reveal very discontinuous P-face ridges. However, the analysis of complementary replicas demonstrates that discontinuities of P-face ridges are always complemented by particles or short bars found in the E-face furrows. Though the problem exists of correlating freeze-fracture images of the junctional structure to the focal passage of horseradish peroxidase, the data suggest that the discontinuities of P-face ridges cannot be the structural counterpart of the passage of horseradish peroxidase. Alternative pathways of horseradish peroxidase are discussed in context with the offset bifibrillary model of the junction.

Pigmentary glaucoma: a clinical review of anterior segment pigment dispersal syndrome.

Sixty-eight cases (44 males, 24 females) of anterior segment pigment dispersal syndrome are reviewed. Five patients had no rise in intraocular pressure, 38 had ocular hypertension and 25 had glaucoma as shown by optic disc cupping and field loss. All cases had heavy deposition of pigment in the drainage angle together with Krukenberg spindles and/or light reflux through the iris. Other evidence of anterior segment pigment dispersal was common. The condition was commonest in young adult males, but could present at any age and in women. Medical treatment was often successful initially, but continued to control pressure in only 17 of 42 patients. Laser trabeculoplasty helped some patients. Drainage operations of various types were successful in 19 of 23 cases. Iris angiography showed evidence of vascular hypoperfusion of the iris which probably precedes pigment dispersal and suggests that the ultimate aetiology may be a congenital deficiency of the mesodermal support tissues of the iris. Some degree of iris stromal atrophy is also common and may become marked. Pigment dispersal from the pigment epithelium of the iris occurs in susceptible individuals and may be associated with the insertion of the dilator muscle. The term anterior segment pigment dispersal seems appropriate as the condition is limited to the anterior segment.

Water soluble marihuana-derived material: pharmacological actions in rabbit and primate.

Further studies have been made with water soluble marihuana-derived material (MDM). Neither adrenergic, cholinergic, aldosterone, dopamine or serotonin antagonism affected the fall in intraocular pressure induced by MDM. Partial blockade was obtained with galactose, glucose, or mannose, but not arabinose, when the latter were given at intravenous concentrations of 1 gm/animal and MDM was given at 25 micrograms animal, suggesting that these sugars may be involved at the active site of the MDM glycoproteins. Dexamethasone was without effect on either intravenous or intravitreal MDM indicating that the MDM effect is not a non-specific response to a protein. A similar plant glycoprotein, larch arabinogalactan, at 200 micrograms/animal was without effect on intraocular pressure. Aqueous humor flow rate was increased 3 hours after MDM administration, a period corresponding to the intraocular pressure increase caused by MDM, and fell to 20% of control values when the fall in intraocular pressure occurred. Blood flow through the iris was increased at both one and six hours after intravenous MDM injection indicating a vasodilation which could contribute to the initial increase in intraocular pressure. Intravitreal injection of MDM in rabbit and rhesus monkey caused a fall in intraocular pressure only after a 24 hour delay: the unilateral response indicated that systemic metabolism was not required for activity and the delay was likely caused by the diffusion time to the ciliary processes from the mid-vitreal injection site. The changes in beta-receptors, adenylate cyclase and carbonic anhydrase in the ciliary processes are minimal indicating a possible vascular mechanism of action of MDM.