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PubMed2004

[The image futures of optical coherence tomography in pathologic myopia].

OBJECTIVE: To study the characteristics of optical coherence tomography (OCT) pictures in pathologic myopia. METHODS: 100 cases (195 eyes) of pathologic myopia were examined with OCT. The Age ranges of all the cases was 16-76 years and refraction error was -6.00 - -36.00 diopters. RESULTS: OCT image was normal in 7 eyes (4.3%), the reflectivity band of RPE and chorio-capillaries were uneven and thinning in 147 eyes (90.2%). Full-thickness macular hole was found in 21 eyes (10.8%), of which 10 (5.1%) eyes were associated with retinal detachment; local shallow retinal detachment was found in 24 eyes (12.3%), of which 7 eyes (3.6%) were associated with retinal schisis, 19 eyes (9.7%) with macular choroidal neovascularization (CNV). retinal swelling was often associated with the following diseases: Fuchs spot 9 eyes (4.6%), thick macular hemorrhage 3 eyes, epiretinal macular membrane 18 eyes (9.2%); macular sensory retina thinning in 5 eyes (2.6%). CONCLUSION: Compared with fundus examination including slit lamp with pan-retinoscope, OCT showed unique preference for observation of the changes of retinal pigment epithelium (RPE), chorio-capillary layer, diagnosis macular hole and epiretinal macular membrane, discovery of small sensory retinal detachment, schisis and thinning of sensory retina layer etc. OCT can not either discover a piece of thin macular hemorrhage or differentiation between thick macular hemorrhage and pigment spot.

Adolescent↗
PubMed1992

Pars plana vitrectomy and direct diathermy for complications of multiple retinal angiomas.

A 16-year-old female had multiple retinal capillary angiomas, complicated by marked retinal and optic disc neovascularization, preretinal membranes, and retinal detachment in her right eye. Pars plana lensectomy, vitrectomy, fluid/gas exchange, direct transvitreal diathermy of the angiomas, endolaser scatter photocoagulation, and scleral buckling resulted in retinal reattachment and regression of the neovascularization. Although additional surgery was necessary for recurrent tractional retinal detachment, long-term retinal reattachment and stable vision was achieved following obliteration of all angiomas.

Adolescent↗
PubMed1992

[Vitreous oxygen tension of proliferative diabetic retinopathy].

The authors investigated the vitreous oxygen tension in 30 eyes of 29 cases of proliferative diabetic retinopathy patients in order to determine the distribution of oxygen tension and the possible role of neovascular tissue in tissue oxygenation. Vitreous oxygen tension was measured using a polarographic oxygen electrode and a PO2 monitoring system (PO-2080). Prior to pars plana vitrectomy, the oxygen electrode was inserted into the vitreous cavity under microscopic observation with dim illumination transmitted fiberoptically. The respective oxygen tension at the mid-vitreous cavity, above the optic disc, above the macula, above the neovascular tissue, in the peripheral vitreous, above the photocoagulated retina and above the non-photocoagulated retina were 15.8 +/- 4.7 mmHg, 31.2 +/- 10.0 mmHg, 17.1 +/- 4.0 mmHg, 32.0 +/- 9.9 mmHg, 15.6 +/- 5.1 mmHg, 16.5 +/- 5.5 mmHg and 18.6 +/- 4.9 mmHg. The oxygen tension values above the neovascular tissue and above the optic disc showed statistically significantly higher values than that of midvitreous cavity. We assume this to be due to differences between the oxygen demand and supply on the neovascular tissue, because in these tissues there are large amounts of vessels and blood flow compared to oxygen consumption. Therefore residual oxygen causes oxygen flow from the neovascularization to the mid-vitreous. This outcome is one of the facts which supports the hypothesis that neovascular tissues develop in order to compensate for retinal ischemia by releasing oxygen.

Adult↗
PubMed1999

Increased vitreous concentrations of human hepatocyte growth factor in proliferative diabetic retinopathy.

Human hepatocyte GF (hHGF) has strong neoangiogenesis activity. The present study was designed to investigate the possible involvement of hHGF in neovascularization in proliferative diabetic retinopathy (PDR) by measuring vitreous hHGF concentrations. The mean vitreous hHGF concentration was higher in subjects with PDR (5.70 +/- 0.68 ng/mL, n = 33) than in nondiabetic control subjects (1.50 +/- 0.20 ng/mL, n = 18, P < 0.01), nondiabetic subjects with proliferative vitreoretinopathy (3.31 +/- 0.57 ng//mL, n = 10, P < 0.05), or diabetic subjects without PDR (1.29 +/- 0.28 ng/mL, n = 8, P < 0.01). PDR subjects with neovascularization of iris, which suggests advanced retinal ischemia, showed a higher mean vitreous hHGF concentration than those without iridal neovascularization [7.33 +/- 1.16 ng/mL (n = 14) vs. 4.49 +/- 0.72 ng/mL (n = 19), P < 0.05]. The mean vitreous hHGF concentration was higher in PDR subjects with retinal neovascularization at the optic disc than in those with neovascularization elsewhere [7.3 +/- 1.1 ng/mL (n = 15) vs. 4.4 +/- 0.7 ng/mL (n = 18), P < 0.05]. Our results indicate that vitreous hHGF may play a role in retinal neovascularization in PDR.

Aged↗
PubMed1990

Cutis marmorata telangiectatica congenita associated with bilateral congenital retinal detachment.

Cutis marmorata telangiectatica congenita is a rare congenital vascular disorder of the skin, characterized by persistent telangiectasia of the cutaneous blood vessels often associated with cutaneous ulcers. The only previously recognized ophthalmic association with this condition has been rare instances of unilateral congenital open angle glaucoma. The authors report their observations in a child in whom this cutaneous disorder was associated with congenital bilateral total retinal detachments and secondary neovascular glaucoma. The retinal detachments produced bilateral leukocoria simulating retinoblastoma. The cutaneous disorder and the ocular findings were confirmed histopathologically.

Corneal Diseases↗
PubMed1990

Scatter photocoagulation restores tissue hypoxia in experimental vasoproliferative microangiopathy in miniature pigs.

Experimental retinal branch vein occlusion using argon laser photocoagulation in miniature pigs induced the development of ischemic retinal territories associated with preretinal neovascularization. Preretinal partial pressure of oxygen (PO2) measurements on the ischemic territories, using O2-sensitive microelectrodes, established that the ischemic retinal areas were hypoxic. Scatter photocoagulation of these ischemic hypoxic territories restores the local PO2 to the normal values within 2 weeks. Hence, the reported inhibitory effect of photocoagulation on the development of retinal neovascularization could be due to a reversal effect on tissue hypoxia.

Animals↗
PubMed2006

Photodynamic therapy for subretinal neovascularization in type 2A idiopathic juxtafoveolar telangiectasis.

BACKGROUND: Photodynamic therapy (PDT) with verteporfin is now the standard of care worldwide for the treatment of choroidal neovascularization, but has been used only rarely in those with subretinal neovascular membranes (SRNVM) due to type 2A idiopathic juxtafoveolar retinal telangiectasis (IJT). We performed a retrospective study to examine the outcome of patients treated with PDT for SRNVM secondary to IJT. METHODS: Retrospective interventional case series of 7 eyes of 6 IJT patients with SRNVMs treated with PDT. Ophthalmic examination and fluorescein angiography were performed before treatment, with retreatment every 3 months as needed. The main outcome was the proportion of patients avoiding vision loss (change of +/- 4 letters, or better). RESULTS: Baseline Snellen acuity ranged from 20/40 to 20/400 (median 20/80). Mean follow-up was 21 months. Patients received 2.4 treatments on average. Five of 7 patients avoided vision loss; acuity improved in 3 eyes (> or = 1 line improvement), stayed the same in 2 eyes (+/- 4 letters) and decreased in 2 eyes (> or = 1 line decrease) over time. Median final acuity was 20/80. Five of 7 eyes had final acuities of > or = 20/200. No leakage was observed in any eyes following cessation of treatment.

Adult↗
PubMed1990

[A role of the retinal pigment epithelium in the involution of subretinal neovascularization].

We clarified a role of the retinal pigment epithelium (RPE) in the regression of experimentally induced subretinal neovascularization (SRN) in monkey. Eight eyes of 5 rhesus monkeys were used in this study. Two weeks after intense krypton laser photocoagulation to the posterior pole of the fundus, 0.5M l-ornithine hydrochloride solution 0.03 ml was injected intravitreously for the purpose of selective RPE damage. After ornithine injection, SRN continued without any evidence of spontaneous regression over 8 weeks following photocoagulation. Histopathologically, SRN developed with wide lumen in the subretinal space accompanied with serous detachment of the sensory retina, and new vessels were not enveloped completely by the proliferating RPE cells. We already showed that experimentally induced subretinal neovascularizations naturally regress spontaneously by envelopment of RPE cells 5 to 8 weeks after photocoagulation. Our results suggested that SRN persist actively without regression due to incomplete enclosure by RPE by selective damage of RPE at the active stage of SRN. We have confirmed that the RPE cells played an important role at the involution stage of SRN.

Animals↗
PubMed1992

Branch retinal vein occlusion and its management.

The natural course of Branch Retinal Vein Occlusion is determined by the site and completeness of the occlusion, the integrity of arterial perfusion to the affected sector and the efficiency of the developing collateral circulation. Most patients with tributary vein occlusion have some capillary fall out and microvascular incompetence in the distribution of the affected retina and vision is significantly compromised in over 50% of patients who have either chronic macular oedema or ischemia involving the perifoveolar arcades. Retinal and capillary vasoproliferation with or without intraretinal or preretinal membrane formation are common sequelae, where inner retinal ischemia is extensive and vitreous hemorrhage is often a distinct threat to vision. Treatment of the sequelae of vein occlusion are largely centered on laser photocoagulation to diseased retina to limit fluid accumulation and abolish preretinal and papillary neovascularization. Vitrectomy and retinal detachment procedures are occasionally required in patients with uncontrolled vitreous hemorrhage and retinal membrane formation which threatens the integrity of the macula. A small proportion of patients with vein occlusion subsequent to vasculitis require medical therapy.

Edema↗
PubMed2006

T2-TrpRS inhibits preretinal neovascularization and enhances physiological vascular regrowth in OIR as assessed by a new method of quantification.

PURPOSE: A carboxyl-terminal fragment of tryptophan tRNA synthetase (T2-TrpRS) has demonstrated potent angiostatic activity during retinal developmental neovascularization in vivo. The effects of T2-TrpRS on pathologic neovascularization were tested and compared with a potent VEGF antagonist using the mouse model of oxygen-induced retinopathy (OIR). METHODS: C57BL/6J mice were transiently exposed to hyperoxic conditions (75% O2) between postnatal day 7 (P7) and P12 and then returned to room air. Retinas were isolated, blood vessels stained with isolectin Griffonia simplicifolia, images of retinal whole-mounts acquired, and the area of vascular obliteration and extent of preretinal neovascularization quantified. This method was compared to the commonly used method of OIR quantification in which the number of pre-inner limiting membrane (ILM) nuclei is counted in serial sections of whole eyes. To assess the angiostatic activity of T2-TrpRS, mice were injected intravitreally at P12 with either T2-TrpRS, a VEGF aptamer, or vehicle (PBS) alone, and the effects on area of obliteration and on preretinal neovascular tuft formation were assessed. RESULTS: Using a modified method of quantification in the mouse OIR model based on images of isolectin-stained retinal wholemounts, we were able to assess reliably and consistently both vascular obliteration and preretinal neovascular tuft formation in the same specimen. T2-TrpRS demonstrated potent angiostatic activity, reducing the appearance of pathologic neovascular tufts by up to 90%. Surprisingly, T2-TrpRS also enhanced physiological revascularization of the obliterated retinal vasculature, reducing these areas by up to 60% compared with PBS-injected eyes. In contrast, the VEGF antagonist, while similarly reducing preretinal neovascular tuft formation, did not enhance revascularization of the obliterated areas. CONCLUSIONS: Use of a rapid, quantifiable method to assess the effect of T2-TrpRS on retinal angiogenesis in the OIR model demonstrates the importance of a quantification system that permits simultaneous analysis of a drug's effect on vascular obliteration as well as on preretinal neovascularization. The results obtained using this method suggest enhanced clinical value for compounds such as T2-TrpRS that not only inhibit pathologic neovascularization, but also facilitate physiological revascularization of ischemic tissue.

Angiostatic Proteins↗
PubMed2004

Angiopoietin-2 enhances retinal vessel sensitivity to vascular endothelial growth factor.

Increased expression of vascular endothelial growth factor (VEGF) in the retina starting after postnatal day (P)7 results in neovascularization originating from deep retinal capillaries, but not those in the superficial capillary bed. Doxycycline was administered starting P0 to double transgenic mice with inducible expression of VEGF in the retina. These mice showed proliferation and dilation of superficial retinal capillaries, indicating that at this stage of development, the superficial capillaries are sensitive to the effects of VEGF. Angiopoietin-2 (Ang2) is expressed along the surface of the retina for several days after birth, but by P7 and later, Ang2 is only expressed in the region of the deep capillary bed. In mice with ubiquitous doxycycline-inducible expression of Ang2, in the absence of doxycycline, intravitreous injection of a gutless adenoviral vector expressing VEGF (AGV.VEGF) resulted in neovascularization of the cornea and iris, but no retinal neovascularization. After treatment with doxycycline to induce Ang2 expression, intravitreous injection of AGV.VEGF caused retinal neovascularization in addition to corneal and iris neovascularization. The retinal neovascularization originated from both the superficial and deep capillary beds. These data suggest that Ang2 promotes sensitivity to the angiogenic effects of VEGF in retinal vessels.

Adenoviridae↗
PubMed2004

Photodynamic therapy of subfoveal neovascular membrane in type 2A idiopathic juxtafoveolar retinal telangiectasis.

PURPOSE: To evaluate the effect of photodynamic therapy on subfoveal neovascular membrane related to type 2A idiopathic juxtafoveolar retinal telangiectasia. DESIGN: Interventional case series. METHODS: Retrospective review of four eyes of four patients who underwent photodynamic therapy for subfoveal neovascular membrane secondary to idiopathic juxtafoveolar retinal telangiectasia. Ocular photodynamic therapy with verteporfin was performed in all cases using standard protocols. Results are given in terms of final visual acuity and neovascular membrane activity based on clinical examination, fluorescein and indocyanin green angiography, and, in two cases, optical coherence tomography. RESULTS: Baseline visual acuity of 20/30 and 20/40 (x2) was maintained in three patients after one, two, and three sessions of photodynamic therapy respectively, and a follow-up of 23, 21, and 9 months. Leakage specific to the subfoveal neovascular membrane ceased on the fluorescein angiography. In the other patient, the final vision decreased from 20/50 to 20/200 after four sessions of photodynamic therapy and a follow-up of 14 months. Although there was still mild persistent leakage on the fluorescein angiography, neovascular membrane size was unchanged, and no subretinal fluid was demonstrated on optical coherence tomography. CONCLUSIONS: Data from this case series suggest that photodynamic therapy may be effective in managing subfoveal neovascular membrane associated with idiopathic juxtafoveolar retinal telangiectasia, which usually carries a poor visual prognosis. Prospective study is required to confirm the beneficial effect of this treatment.

Aged↗
PubMed1999

Experimental preretinal neovascularization by laser-induced thrombosis in albino rats.

The primary objective of this study was to develop a simple experimental model of angiogenesis by photodynamic thrombosis of the retinal veins in Sprague-Dawley rats. After a tail vein injection of rose bengal (40 mg/kg), all major retinal veins adjacent to the optic nerve head were photocoagulated with an argon green laser. The eyes were examined regularly for the following eight weeks. A grading system was devised using fluorescein angiograms and ADPase staining to describe the progression of the new vessels. Nine out of ten eyes showed development of the preretinal new vessels by day 14. Seven weeks after laser coagulation, 2 of 5 eyes developed localized tractional retinal detachment. Regression of the neovascularization was not noted in any of the animals during the follow-up period. The authors were able to establish an experimental model for preretinal neovascularization by vein occlusion. This model may be applied in study of the pathogenesis and treatment of retinal neovascularization.

Animals↗
PubMed1996

Interferon alfa induces leukocyte capillary trapping in rat retinal microcirculation.

BACKGROUND: Interferon alfa has been suggested as a possible treatment for choroidal neovascularization. However, retinal complications following interferon therapy have been reported. OBJECTIVE: To evaluate the effects of interferon alfa on leukocyte dynamics in the rat retinal microcirculation. METHODS: Interferon alfa of different doses was intravenously administered in rats. Leukocyte dynamics were observed with acridine orange digital fluorography, which uses a nuclear fluorescent dye of acridine orange and scanning laser ophthalmoscopy. This technique allows visualization of leukocyte movements in the retinal microcirculation in vivo. RESULTS: After interferon alfa was administered, leukocytes adhered to vascular walls and became trapped in the retinal microcirculation. Leukocyte trapping was dose-dependent. CONCLUSIONS: Interferon alfa increased leukocyte adherence to vascular endothelium and subsequent leukocyte trapping in the retinal capillaries. Interferon alfa may activate leukocytes, and activated leukocytes may be involved in the pathogenesis of microinfarction associated with interferon-induced retinopathy.

Acridine Orange↗
PubMed2006

Nf1 haploinsufficiency augments angiogenesis.

Mutations in the NF1 tumor-suppressor gene underlie neurofibromatosis type 1 (NF1), in which patients are predisposed to certain tumors such as neurofibromas and may associate with vascular disorder. Plexiform neurofibromas are slow growing benign tumors that are highly vascular and can progress to malignancy. The development of neurofibromas requires loss of both Nf1 alleles in Schwann cells destined to become neoplastic and may be exacerbated by Nf1 heterozygosity in other non-neoplastic cells. This study tested the hypothesis that Nf1 heterozygosity exaggerates angiogenesis. We found that Nf1 heterozygous mice showed increased neovascularization in both the retina and cornea in response to hypoxia and bFGF, respectively, compared to their wild-type littermates. The increase in corneal neovascularization was associated with heightened endothelial cell proliferation and migration, and increased infiltration of inflammatory cells. In addition, Nf1 heterozygous endothelial cell cultures showed an exaggerated proliferative response to angiogenic factors, particularly to bFGF. These findings support the conclusion that Nf1 heterozygosity in endothelial cells and perhaps inflammatory cells augments angiogenesis, which may promote neurofibroma formation in NF1.

Animals↗
PubMedDate not supplied

Retinopathy in incontinentia pigmenti: a neonatal case report.

A female infant had erythematous vesicular skin lesions over the whole body and extremities in the early infancy. These skin lesions then changed to hyperpigmentation in whorls and splashes. Seizure attack was noted at one month old. Skin biopsy showed dyskeratosis, acanthosis, pigmenti incontinence, and massive infiltration of eosinophils. So Incontinentia pigmenti was confirmed. She also had hallmarks of retinal involvement, including peripheral retinal ischemia and neovascularization, which were similar to those seen in retinopathy of prematurity. Cryopexy was performed in her left eye and the lesions regressed.

Female↗