Metabolic control and diabetic retinopathy.

The Early Treatment Diabetic Retinopathy Study (ETDRS) identified important risk factors for progression to high risk proliferative diabetic retinopathy (PDR) including retinopathy severity, decreased visual acuity, and high levels of hemoglobin A1C (HbA1c). Additional risk factors for progression to PDR are decreased hematocrit and increased serum lipids. The long-term benefit of improving glycemic control was evaluated by three large studies: the Diabetes Control and Complications Trial (DCCT), the Stockholm Interventional Study, and the UK prospective study. Several small studies, notably the Kuwamoto study, also evaluated the relationship between the glycemic control and diabetic retinopathy. Intensive glycemic control reduces the risk of any retinopathy by approximately 27%. Intensive therapy is most effective when initiated early in the course of the diabetes, demonstrating a beneficial effect over the course and progression of retinopathy. The long term benefits of the intensive glycemic control greatly outweigh the risk of "early worsening." Lowering elevated serum lipid levels has been shown to decrease the risk of cardiovascular morbidity. The ETDRS data suggest that lipid lowering may also decrease the risk of hard exudate formation and associated vision loss in patients with diabetic retinopathy. Preservation of vision may be an additional motivating factor for lowering serum lipid levels in persons with diabetic retinopathy and elevated serum lipid levels.

Diabetic retinopathy and angiogenesis.

Diabetic retinopathy, a secondary microvascular complication of diabetes mellitus is the leading cause of blindness in the Unites States amongst individuals age 20 to 64. Two major retinal problems cause most of the diabetes-related vision loss: diabetic macular edema and complications from abnormal retinal blood vessel growth, angiogenesis. Secondary to angiogenesis, increased retinal blood flow is of pathogenic importance in the progression of diabetic retinopathy. Understanding the role of hyperglycemia seems to be the most critical factor in regulating retinal blood flow, as increased levels of blood glucose are thought to have a structural and physiological effect on retinal capillaries causing them to be both functionally and anatomically incompetent. High blood glucose induces hypoxia in retinal tissues, thus leading to the production of VEGF-A (vascular endothelial growth factor protein). Hypoxia is a key regulator of VEGF-induced ocular neovascularization. Secondary to the induction of VEGF by hypoxia, angiogenesis can be controlled by angiogenic inducers and inhibitors. The balance between VEGF and angiogenic inhibitors may determine the proliferation of angiogenesis in diabetic retinopathy. Since VEGF-A is a powerful angiogenic inducer, utilizing anti-VEGF treatments has proved to be a successful protocol in the treatment of proliferative diabetic retinopathy.

Ranibizumab for diabetic retinopathy.

Ranibizumab (Lucentis) is a Fab-Antibody with high affinity for VEGF, and is being designed to bind to all VEGF isoforms. This quality makes it a powerful drug for VEGF inhibition. Diseases of retinal and choroidal blood vessels are the most prevalent causes of moderate and severe vision loss in developed countries. Vascular endothelial growth factor plays a critical role in the pathogenesis of many of these diseases. Results of the pilot studies showed that intraocular injections of ranibizumab (Lucentis) decrease the mean retinal thickness and improve the BCVA in all the subjects. Proliferative diabetic retinopathy, currently treated with destructive laser photocoagulation, represents another potential target for anti-VEGF therapy. The early experience in animal models with proliferative retinopathy and neovascular glaucoma shows that posterior and anterior neovascularizations are very sensitive to anti-VEGF therapy. The outcome of two phase III clinical trials will increase our knowledge of the role of Lucentis in the treatment of DME.

Functional and anatomical outcomes for intravitreal bevacizumab treatment of choroidal neovascularization in a patient with angioid streaks.

PURPOSE: To evaluate the visual and anatomical outcomes of intravitreal bevacizumab (Avastin; Genentech, Inc., South San Francisco, CA) treatment of choroidal neovascularization (CNV) in patients with angioid streaks (ASs). METHODS: A 44-year-old man with angioid streaks and CNV in both eyes (best-corrected visual acuity: 20/400, right eye; 20/50, left eye) received intravitreal bevacizumab injections at monthly intervals. RESULTS: Best-corrected visual acuity in the right eye after 2 intravitreal injections of bevacizumab was 20/70 and remained the same at the 6-month follow-up. Best-corrected visual acuity in the left eye after 3 intravitreal injections of bevacizumab was 20/25 and remained the same at the 9-month follow-up. CONCLUSIONS: After intravitreal administration of bevacizumab, our patient had visual acuity improvement in both eyes that was associated with rapid and significant reduction in thickness, subretinal fluid, and size of subfoveal neovascularization secondary to ASs. Intravitreal bevacizumab treatment resulted in a meaningful and sustained vision gain after the 9-months follow-up.

Preliminary results of combined simultaneous transpupillary thermotherapy and ICG-based photodynamic therapy for choroidal melanoma.

BACKGROUND AND OBJECTIVE: To evaluate whether the combination of simultaneous hyperthermia by transpupillary thermotherapy and indocyanine green-based photodynamic therapy is an effective treatment for small and medium choroidal melanomas. PATIENTS AND METHODS: Twenty-five patients with small and medium choroidal melanomas were treated with combined simultaneous transpupillary thermotherapy and indocyanine green-based photodynamic therapy. RESULTS: The median age of the 25 patients was 64 years (range, 35 to 88 years). The pretreatment volume of the tumors ranged from 15.9 to 653.5 mm3 (mean, 118.7 +/- 146.6 mm3). After a mean of 2.4 treatments (range, 1 to 5 treatments), all of the tumors but one showed a significant volume reduction without clinical evidence of recurrences. The follow-up ranged from 6 to 59 months (mean, 12 +/- 14 months). Complications included retinal vascular occlusions, edema and superficial scarring of the macula, and rhegmatogenous retinal detachment. CONCLUSIONS: The effects of combined simultaneous transpupillary thermotherapy and indocyanine green-based photodynamic therapy appears to be effective in achieving local tumor control in selected small and medium choroidal melanomas.

Anti-macular degeneration agents.

Anti-VEGF therapy is a promising new avenue for the treatment of ocular neovascular diseases. Early preclinical data and recent clinical data support the efficacy and safety of several novel anti-VEGF for NVAMD. Whether these novel biologics are used on their own, in combination with previously available therapies, or with newly developing therapies, they represent a new avenue in treatment. These agents are highly selective in their targeted approaches, and when administered appropriately , offer treatment with minimal damage to retinal tissue. In the future, biotherapeutic agents will certainly play a powerful role in the treatment of human choroidal neovascular membrane formation.

Fishing-related ocular trauma.

PURPOSE: To evaluate the characteristics of fishing-related ocular injuries. DESIGN: Retrospective observational analysis of a computerized databank. METHODS: The United States Eye Injury Registry was used to analyze 143 patients with fishing-related ocular injury. Epidemiologic and clinical information was evaluated including the age and gender of the subjects, classification of ocular trauma, surgical management, and final visual acuity. RESULTS: Of the 732 cases of sport-related ocular trauma, 143 (19.54%) occurred while fishing; of these, 79% were male patients who ranged in age from 6 to 68 years (mean, 37 years). Corneal laceration, globe rupture, and hyphema were the most common diagnoses at presentation and were caused by fishing hooks, lures, and weights. Thirty-five bystanders are included in the study. Thirty-eight percent of patients had visual acuity less than 20/50, and 21% had a visual acuity of less than 20/200. Open globe injuries portended a poor visual outcome compared with closed globe injuries. CONCLUSIONS: Fishing-related ocular injuries represent a large percent of sports-related trauma, often resulting in significant visual loss. Preventive measures such as the use of protective eyewear should be advised in this activity.