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Proliferative radiation retinopathy.

OBJECTIVES: To compare proliferative radiation retinopathy (PRR) with nonproliferative radiation retinopathy (NPRR) and to assess the outcome of panretinal photocoagulation treatment for PRR. METHODS: We reviewed the medical records, fundus photographs, and fluorescein angiograms of 10 patients (14 eyes) with PRR, which was diagnosed in a tertiary referral center during a 20-year period. The collected data included the following: the indications for radiation treatment, radiotherapy technique used, dose and fractions of radiation, visual acuity, indications for photocoagulation treatment, photocoagulation technique used, and response to treatment. Comparisons were made with data from 17 patients (27 eyes) with NPRR, which had not progressed to PRR during the course of this study. RESULTS: The initial visual acuity of the 14 eyes with PRR ranged from 20/20 to hand motion; these eyes had a median visual acuity of 20/90. The initial visual acuity of the 27 eyes with NPRR ranged from 20/15 to 20/400; these eyes had a median visual acuity of 20/25. Five (36%) of the eyes with PRR and 4 (15%) of the eyes with NPRR (P = .35) had a visual acuity of 20/200 or worse. After a mean follow-up time of 75 months for the eyes with PRR and 51 months for the eyes with NPRR, the median visual acuities were 20/400 and 20/50, respectively; 12 (86%) of the 14 eyes with PRR had a visual acuity of 20/200 or worse vs 7 (26%) of the 27 eyes with NPRR (P < .007). The new vessels had resolved in 10 (91%) of the 11 eyes that were treated with panretinal photocoagulation for PRR. CONCLUSIONS: Eyes with PRR have a poor prognosis for retaining and regaining good central vision. Panretinal photocoagulation seems to have long-term effectiveness in decreasing the proliferation of new vessels due to complications of radiation treatment.

Eye Neoplasms↗

Molecular targets for retinal vascular diseases.

The elucidation of the molecular pathogenesis of a disease in animal models provides candidate targets for treatment. As specific antagonists for a target are developed and tested in clinical trials, if benefit is achieved, the candidate becomes a validated target. Validated targets stimulate additional research to identify optimal ways of attacking the target and studies in related disease processes to determine if the molecule is also a target in that context. Vascular endothelial growth factor (VEGF) has been identified as a validated target for several retinal vascular diseases. This has led to a flurry of activity resulting in beneficial treatments for patients and intensification of the search for other targets. This review summarizes preclinical and clinical trial results obtained with VEGF antagonists and describes evidence supporting the candidacy of other molecules currently being tested or soon to be tested for target status.

Animals↗

Quantitative mapping of ocular oxygenation using magnetic resonance imaging.

Retinal hypoxia is hypothesized to initiate angiogenesis, a leading cause of blindness in developed countries. Attempts to test this hypothesis suffer from the need to use highly invasive oxygen electrodes. In this communication, noninvasive and quantitative mapping of ocular oxygenation using magnetic resonance imaging is demonstrated for the first time.

Animals↗

Expression of the VEGF gene family during retinal vaso-obliteration and hypoxia.

Vascular insufficiency and retinal ischaemia precede many proliferative retinopathies and stimulate secretion of vasoactive growth factors. Vascular endothelial growth factor (VEGF) plays a major role and we therefore investigated the other members of the VEGF family: Placental growth factor (PlGF), VEGF-B, -C, and -D, and platelet derived growth factors (PDGF) A and B. Neonatal mice were exposed to hyperoxia for 5 days and then returned to room air (resulting in acute retinal ischaemia). RT-PCR demonstrated that all the members of the VEGF family are expressed in the retina and in situ hybridization (ISH) located their mRNAs primarily in ganglion cells. Similarly to VEGF itself, VEGF-C, PDGF-A, and PDGF-B were upregulated during retinal ischaemia (P < 0.05). Only PlGF gene expression increased during hyperoxia (P < 0.01). The expression pattern of these growth factors suggests a role in the normal retina and during vaso-obliterative and ischaemic phases.

Animals↗

Oxygen toxicity in premature infants.

Oxygen causes tissue injury through the formation of reactive oxygen intermediates and peroxidation of membrane lipids. Premature infants, who have severely reduced antioxidant defenses, are particularly sensitive to the toxic effects of oxygen. Supplemental oxygen in premature infants contributes to the development of chronic lung disease (bronchopulmonary dysplasia), characterized by dysregulated inflammation and altered expression of proteases and growth factors. This can result in fibrosis, asymmetric aeration, and respiratory insufficiency. Oxygen also induces aberrant physiologic responses that can be damaging in premature infants. For example, vasoconstriction in the retina is an early response to oxygen that can lead to vasoobliteration, neovascularization, and retinal traction (retinopathy of prematurity). Increasing knowledge of the mechanisms underlying oxygen toxicity in premature infants has suggested strategies to minimize tissue injury and to optimize long-term medical outcomes. These include limiting oxygen supplementation and light exposure, the use of antiinflammatory agents or antioxidants, and the use of room air in neonatal resuscitation.

Antioxidants↗

Ocular findings in sickle cell patients on Curaçao.

We examined about half the estimated number (based on gene frequency) of sickle cell patients on the island of Curaçao. This study may represent one of the most comprehensive and a selective cross-sectional surveys available. Studying 81 Hb SS and 97 Hb SC patients, we were able to confirm the correlation between iris atrophy and proliferative sickle retinopathy (PSR), the correlation between Hb SC and proliferative sickle retinopathy (PSR) and the major role of PSR in blindness in sickle cell patients. In Hb SC patients over the age of 18 PSR occurred in 50%, leading to vitreous hemorrhage in 18% and to retinal detachment in 8%. We found a frequency of blindness in one eye (fingers counting or less) of 4% in the entire sickle population, and 6% among Hb SC patients. Bilateral blindness was rare: one Hb SS patient, due to cortical blindness. The relatively frequent occurrence of severe complications in a narrowly defined population should stimulate our efforts to prevent these from occurring.

Adolescent↗

Bilateral blindness in cavernous sinus thrombosis.

An unusual case of bilateral blindness secondary to a cavernous sinus thrombosis is reported. A woman who had undergone reconstructive surgery after tumor resection of the floor of the mouth, was readmitted 1 month later with bilateral proptosis and signs of sepsis. There were no complaints of blurred vision. A CT-scan of the orbits demonstrated a bilateral cavernous sinus thrombosis (CST) secondary to an infection at the skull base behind the myocutaneous flap. A few days later she became blind, due to bilateral central retinal artery occlusion and anterior ischemic optic neuropathy. The general critical condition improved with intensive AB treatment. The patient recovered well without neurological defects apart from her permanent bilateral blindness. There were no signs of tumor recurrence. To our knowledge, this is the first documented case of bilateral blindness in a patient suffering from CST.

Blindness↗

Macular oedema and retinal neovascularisation in juvenile diabetics.

Thirteen young diabetic patients with peripheral capillary non perfusion who presented with symptoms of mild maculopathy were reviewed retrospectively. In this group, peripheral retinal ischaemia was often overlooked and a rapidly progressive proliferative retinopathy developed. Fluorescein angiography of the peripheral retina showed capillary closure, but with preservation of arterioles and venules. In this series, half of the eyes lost vision. In seven eyes where the peripheral ischaemia was treated by pan retinal photocoagulation, the maculopathy resolved without any specific laser treatment to the macula. In young diabetics presenting with maculopathy, the peripheral retina should be examined for ischaemia, and if present, pan retinal laser photocoagulation should be performed. Focal treatment for the macular disease can be delayed until after the peripheral photocoagulation, as the maculopathy may remit.

Adolescent↗

Retinopathy of prematurity.

This review deals with retinopathy of prematurity (ROP), a disease characterized by retinovitreal neovascularization, eventually retinal detachment and blindness. Due to the increasing number of extremely premature newborns, it is becoming more frequent. ROP of all stages occurs in 25-35% of surviving premature newborns of gestational age up to approximately 35 weeks. Stages 3 or more occur in 5-10%, blindness in 3-5% of very immature babies. The incidence is inversely related to gestational age. Classification is internationally unified (ICROP) and describes 5 stages. Its pathogenesis has not yet been clarified. More or less proven risk factors are retinovascular immaturity, hyperoxia and possibly circulatory and respiratory instability. Prophylaxis consists in avoiding hyperoxia, and probably also in keeping the extremely premature newborn stable. Ophthalmologic examinations must be performed by ophthalmologists experienced in this field or under their direct responsibility and must be standardized. Treatment of ROP can be carried out at a certain stage by coagulation therapy.

Gestational Age↗

Posterior vitreous detachment following panretinal laser photocoagulation.

A total of 30 eyes of 19 patients with type I diabetes, varying severity of retinopathy, and no posterior vitreous detachment (PVD) were studied clinically, and vitreous examination was performed by preset lens biomicroscopy. Follow-up was 4.0-7.5 years. A total of 15 eyes underwent panretinal laser photocoagulation (PRP) and 15 eyes were left untreated. The incidence of PVD was 8 of 15 353%) after PRP and 1 of 15 (7%) in untreated eyes (P less than 0.02). Minimal vitreous hemorrhage occurred in 4 of 7 treated eyes (57%) that did not develop PVD and in only 2 of 8 (25%) that did. In treated eyes with no history of vitreous hemorrhage, the incidence of PVD was 6/9 (67%); in treated eyes with minimal vitreous hemorrhage at any time, it was 2/6 (33%). In treated eyes, the presence of Diabetic Retinopathy Study (DRS) high-risk characteristics was equally frequent in eyes that developed PVD as in those that did not. These data suggest that PVD occurs following PRP, independent of the severity of diabetic retinopathy or prior vitreous hemorrhage.

Adult↗

[Limits and possibilities of vitreous body surgery in diabetic retinopathy].

BACKGROUND: Several indications for vitreous surgery for complications of diabetic retinopathy have been established, but there is little well-founded information concerning situations in which visual prognosis is poor and vitreous surgery should not be performed. MATERIALS AND METHODS: The charts of 389 patients who had undergone vitreous surgery for complications of diabetic retinopathy between 1990 and 1994 were retrospectively reviewed. The minimum follow-up was 6 months with a median of 26 months. Using multivariate logistic regression analysis we studied factors which were correlated with a postoperative visual acuity of less than 5/200. A model was developed predicting the probability of an unfavorable visual outcome in various situations. RESULTS: Forty-five eyes (12%) had a best postoperative visual acuity of less than 5/200. Risk factors were detachment of the macula, extent of the detachment, iris neovascularisations and the duration of visual loss. For reoperations similar risk factors were found. The chance that an eye with total tractional retinal detachment of more than 6 months duration and with rubeosis of the iris will achieve a postoperative visual acuity of 5/200 or better is only 2%. CONCLUSIONS: Eyes with total tractional retinal detachment, especially with longer duration of the detachment and rubeosis, have a very poor chance of achieving useful vision and should not be operated.

Adult↗

[Vitrectomy in advanced Coats disease].

BACKGROUND: Coats disease is a retinal vasculopathy of unknown cause. Untreated cases usually lead to an exudative retinal detachment and rubeosis iridis with secondary glaucoma. Photocoagulation and/or cryotherapy are generally the first interventions in treating the disease. Pars plana vitrectomy may be indicated in cases of vitreous hemorrhage or retinal detachment. METHODS: We performed pars plana vitrectomy in 9 eyes with Coats disease between 1992 and 1999. A retinal detachment was present in 3 cases, and three showed a vitreous hemorrhage. In two cases surgery was indicated because of paramacular localization of the pathological vessels with associated exudations. RESULTS: The two cases with paramacular involvement showed improvement in visual acuity of eight lines. In the remaining cases visual acuity remained within two lines compared to the initial visual acuity. All eyes except one could be saved. CONCLUSION: Pars plana vitrectomy is a useful option in treating advanced Coats disease, especially in cases associated with vitreous hemorrhage or retinal traction.

Adolescent↗