yulius hermanto
Understanding Diabetic Retinopathy
Introduction
Diabetic retinopathy is a disease that affect retina that occurs in patients with long-standing diabetes mellitus, and develops to some degree from mild to severe.
Burden of Disease
According to recent statistics, about 19 million Americans aged 20 years or older have either diagnosed or undiagnosed diabetes mellitus; about one-third are not aware that they have the disease. An additional 26% of adults (54 million persons) have impaired fasting blood glucose levels. In the United States, an estimated three out of five people with diabetes have one or more of the complications associated with the disease.
With the increasing population with diabetes, surely will increase the health complications related to diabetes. One of them is diabetic retinopathy.
Recently, Diabetic retinopathy is a leading cause of new cases of legal blindness among working-age in developed nations. The prevalence rate for retinopathy for adults aged 40 years and older in the United States is 3.4% (4.1 million persons); the prevalence rate for vision-threatening retinopathy is 0.75% (899,000 persons). Assuming a similar prevalence of diabetes mellitus, the projected numbers in 2020 would be 6 million persons with diabetic retinopathy and 1.34 million persons with vision-threatening diabetic retinopathy.
Risk Factors
The important risk factor of having diabetic retinopathy is having a diabetes, whether it types I or II, it doesn't matter. Since this disease only occurs in person who has diabetes.
Another risk factor is Duration of diabetes, this factor is highly associated with the development of diabetic retinopathy. After 5 years, approximately 25% of type 1 patients have retinopathy. After 10 years, almost 60% have retinopathy, and after 15 years, 80% have retinopathy. And for type 2 patients who have a known duration of diabetes of less than 5 years, 40% of those patients taking insulin and 24% of those not taking insulin have retinopathy. These rates increase to 84% and 53%, respectively, when the duration of diabetes has been documented for up to 19 years. Proliferative diabetic retinopathy develops in 2% of type 2 patients who have diabetes for less than 5 years and in 25% of patients who have diabetes for 25 years or more. These percentages are based on data from the 1980s before there was closer monitoring and tighter glycemic control, and they may have improved.
Well, in conclusion we can say that the longer a person has diabetes the higher risk for diabetic retinopathy.
The severity of hyperglycemia is the key alterable risk factor associated with the development of diabetic retinopathy. There is general agreement that duration of diabetes and severity of hyperglycemia are the major risk factors for developing retinopathy.
Anyway, once retinopathy is present, duration of diabetes appears to be a less important factor than hyperglycemia for progression from earlier to later stages of retinopathy.
Others risk factors such as Intensive management of hypertension has been demonstrated to slow retinopathy progression, and elevated serum lipid levels are associated with the development of retinopathy.
There is less agreement among studies concerning the importance of other factors such as age, type of diabetes, clotting factors, renal disease, physical inactivity, and use of angiotensin-converting enzyme inhibitors. Many of these factors are associated with the substantial cardiovascular morbidity and mortality and other complications associated with diabetes. Thus, it is reasonable to encourage patients with diabetes to be as compliant as possible with therapy of all medical aspects of their disease.
Disease Progression
The progression of Diabetic retinopathy can be predicted in an orderly fashion from minimal changes to more severe stages if there is no intervention. It is important to recognize the stages in which treatment may be beneficial. Several decades of clinical research have provided excellent data on the natural course of the disease and on treatment strategies that are 90% effective in preventing the occurrence of severe vision loss.
The earliest clinically apparent stages is called nonproliferative diabetic retinopathy (NPDR) and is characterized by retinal vascular abnormalities including microaneurysms, intraretinal hemorrhages, and cotton-wool spots. Increased retinal vascular permeability that occurs at this or later stages of retinopathy may result in retinal thickening (edema) and lipid deposits (hard exudates). Clinically significant macular edema (CSME) is a term commonly used to describe retinal thickening and/or adjacent hard exudates that either involve the center of the macula or threaten to spread into it. Patients with macular edema, will experience a blurred vision, color disturbances, distorted images, etc. since macula is the center of vision. These patients should be considered for focal laser photocoagulation, particularly if the center of the macula is already involved or if retinal thickening/adjacent hard exudates are very close to it.
As diabetic retinopathy progresses, there is a gradual closure of retinal vessels, which results in impaired perfusion and retinal ischemia. Signs of increasing ischemia include venous abnormalities (e.g., beading, loops), microaneurysms, and more severe and extensive vascular leakage characterized by increasing retinal hemorrhages and exudation. When these signs progress beyond certain defined thresholds, severe NPDR is diagnosed. Patients with this degree of retinopathy should be considered for possible treatment with panretinal (scatter) laser photocoagulation.
The more advanced stage, proliferative diabetic retinopathy (PDR), is characterized by the onset of neovascularization of the inner surface of the retina induced by the retinal ischemia. New vessels at the optic disc (NVD) and new vessels elsewhere in the retina (NVE) are prone to bleed, resulting in vitreous hemorrhage. These new vessels may undergo fibrosis and contraction; this and other fibrous proliferation may result in epiretinal membrane formation, vitreoretinal traction bands, retinal tears, and traction or rhegmatogenous retinal detachments.
When new vessels are accompanied by vitreous hemorrhage, or when new vessels at the optic disc occupy greater than or equal to about one-quarter to one-third disc area, even in the absence of vitreous hemorrhage, PDR is said to be in the high-risk stage.
Neovascular glaucoma can result from new vessels growing on the iris and anterior chamber angle structures. Patients with neovascular glaucoma or high-risk PDR should receive prompt panretinal photocoagulation.
Prevention and Early Detection
Primary prevention of diabetic retinopathy is by not having diabetes, do a healthy lifestyle with exercise and weight control may decrease the risk of developing diabetes in some patients. With the prevention of diabetes surely will prevent the occurance of diabetic retinopathy.
In many cases the blinding complications of diabetes mellitus can be prevented or moderated. Recent innovations in treatment can yield substantial cost savings compared with the direct costs for those disabled by vision loss.
The early detection is need to emphasize in order to identify earliest stages of diabetic retinopathy thus can properly treated. They are several forms of retinal screening with standard fundus photography or digital imaging, with and without dilation, are being investigated as a means of detecting retinopathy.
Appropriately validated digital imaging technology can be a sensitive and effective screening tool to identify patients with diabetic retinopathy for referral for ophthalmic evaluation and management. Digital cameras with stereoscopic capabilities are useful for identifying subtle neovascularization and macular edema. At this time, it is not clear that photographic screening programs achieve a greater reduction in vision loss than does routine community care in areas where access to ophthalmologists is straightforward.
At this time, these technologies are not considered a replacement for a comprehensive eye evaluation by an ophthalmologist experienced in managing diabetic retinopathy. Furthermore, an ophthalmologists, also can play an important role in the total care of the patient with diabetes. For example, at the time of the eye examination, patients can be counseled about the importance of blood glucose and blood pressure control.
But, the problems most of diabetic patients doesn't know when to find an opthalmologist since they doesn't any changes in visions. Current recommendation stated that annual eye examination is needed for the patients that having diabetes at least 5 years.
The development and progression of diabetic retinopathy in patients with type 1 diabetes can be delayed if glucose concentrations are maintained in the near-normal range. Strict glucose control also resulted in a 50% reduction in the rate of progression of retinopathy in patients with existing retinopathy. At the 6- and 12-month visits, a small number of patients had a transient early worsening of the retinopathy in the intensive treatment group, but there was no effect on visual acuity.
In patients with newly diagnosed type 2 diabetes. Intensive blood glucose control by either the sulfonylureas or insulin decreased the risk of microvascular complications but not the risk of macrovascular disease. There were no adverse effects of the individual drugs on the cardiovascular outcome. In this study, there was a 29% reduction in the need for retinal photocoagulation surgery in the group with intensive glucose therapy compared with those receiving conventional treatment.
Conclusion
It is important to educate all patients who have diabetes about the disease and to emphasize the value of maintaining blood glucose (as monitored by hemoglobin A1c) as near normal as is safely possible. The studies have shown that lowering blood glucose reduces other end-organ complications as well, including nephropathy and neuropathy and cardiovascular disease.
Diabetic retinopathy is a disease that affect retina that occurs in patients with long-standing diabetes mellitus, and develops to some degree from mild to severe.
Burden of Disease
According to recent statistics, about 19 million Americans aged 20 years or older have either diagnosed or undiagnosed diabetes mellitus; about one-third are not aware that they have the disease. An additional 26% of adults (54 million persons) have impaired fasting blood glucose levels. In the United States, an estimated three out of five people with diabetes have one or more of the complications associated with the disease.
With the increasing population with diabetes, surely will increase the health complications related to diabetes. One of them is diabetic retinopathy.
Recently, Diabetic retinopathy is a leading cause of new cases of legal blindness among working-age in developed nations. The prevalence rate for retinopathy for adults aged 40 years and older in the United States is 3.4% (4.1 million persons); the prevalence rate for vision-threatening retinopathy is 0.75% (899,000 persons). Assuming a similar prevalence of diabetes mellitus, the projected numbers in 2020 would be 6 million persons with diabetic retinopathy and 1.34 million persons with vision-threatening diabetic retinopathy.
Risk Factors
The important risk factor of having diabetic retinopathy is having a diabetes, whether it types I or II, it doesn't matter. Since this disease only occurs in person who has diabetes.
Another risk factor is Duration of diabetes, this factor is highly associated with the development of diabetic retinopathy. After 5 years, approximately 25% of type 1 patients have retinopathy. After 10 years, almost 60% have retinopathy, and after 15 years, 80% have retinopathy. And for type 2 patients who have a known duration of diabetes of less than 5 years, 40% of those patients taking insulin and 24% of those not taking insulin have retinopathy. These rates increase to 84% and 53%, respectively, when the duration of diabetes has been documented for up to 19 years. Proliferative diabetic retinopathy develops in 2% of type 2 patients who have diabetes for less than 5 years and in 25% of patients who have diabetes for 25 years or more. These percentages are based on data from the 1980s before there was closer monitoring and tighter glycemic control, and they may have improved.
The severity of hyperglycemia is the key alterable risk factor associated with the development of diabetic retinopathy. There is general agreement that duration of diabetes and severity of hyperglycemia are the major risk factors for developing retinopathy.
Anyway, once retinopathy is present, duration of diabetes appears to be a less important factor than hyperglycemia for progression from earlier to later stages of retinopathy.
Others risk factors such as Intensive management of hypertension has been demonstrated to slow retinopathy progression, and elevated serum lipid levels are associated with the development of retinopathy.
There is less agreement among studies concerning the importance of other factors such as age, type of diabetes, clotting factors, renal disease, physical inactivity, and use of angiotensin-converting enzyme inhibitors. Many of these factors are associated with the substantial cardiovascular morbidity and mortality and other complications associated with diabetes. Thus, it is reasonable to encourage patients with diabetes to be as compliant as possible with therapy of all medical aspects of their disease.
Disease Progression
The progression of Diabetic retinopathy can be predicted in an orderly fashion from minimal changes to more severe stages if there is no intervention. It is important to recognize the stages in which treatment may be beneficial. Several decades of clinical research have provided excellent data on the natural course of the disease and on treatment strategies that are 90% effective in preventing the occurrence of severe vision loss.
The earliest clinically apparent stages is called nonproliferative diabetic retinopathy (NPDR) and is characterized by retinal vascular abnormalities including microaneurysms, intraretinal hemorrhages, and cotton-wool spots. Increased retinal vascular permeability that occurs at this or later stages of retinopathy may result in retinal thickening (edema) and lipid deposits (hard exudates). Clinically significant macular edema (CSME) is a term commonly used to describe retinal thickening and/or adjacent hard exudates that either involve the center of the macula or threaten to spread into it. Patients with macular edema, will experience a blurred vision, color disturbances, distorted images, etc. since macula is the center of vision. These patients should be considered for focal laser photocoagulation, particularly if the center of the macula is already involved or if retinal thickening/adjacent hard exudates are very close to it.
As diabetic retinopathy progresses, there is a gradual closure of retinal vessels, which results in impaired perfusion and retinal ischemia. Signs of increasing ischemia include venous abnormalities (e.g., beading, loops), microaneurysms, and more severe and extensive vascular leakage characterized by increasing retinal hemorrhages and exudation. When these signs progress beyond certain defined thresholds, severe NPDR is diagnosed. Patients with this degree of retinopathy should be considered for possible treatment with panretinal (scatter) laser photocoagulation.
The more advanced stage, proliferative diabetic retinopathy (PDR), is characterized by the onset of neovascularization of the inner surface of the retina induced by the retinal ischemia. New vessels at the optic disc (NVD) and new vessels elsewhere in the retina (NVE) are prone to bleed, resulting in vitreous hemorrhage. These new vessels may undergo fibrosis and contraction; this and other fibrous proliferation may result in epiretinal membrane formation, vitreoretinal traction bands, retinal tears, and traction or rhegmatogenous retinal detachments.
When new vessels are accompanied by vitreous hemorrhage, or when new vessels at the optic disc occupy greater than or equal to about one-quarter to one-third disc area, even in the absence of vitreous hemorrhage, PDR is said to be in the high-risk stage.
Neovascular glaucoma can result from new vessels growing on the iris and anterior chamber angle structures. Patients with neovascular glaucoma or high-risk PDR should receive prompt panretinal photocoagulation.
Prevention and Early Detection
Primary prevention of diabetic retinopathy is by not having diabetes, do a healthy lifestyle with exercise and weight control may decrease the risk of developing diabetes in some patients. With the prevention of diabetes surely will prevent the occurance of diabetic retinopathy.
In many cases the blinding complications of diabetes mellitus can be prevented or moderated. Recent innovations in treatment can yield substantial cost savings compared with the direct costs for those disabled by vision loss.
The early detection is need to emphasize in order to identify earliest stages of diabetic retinopathy thus can properly treated. They are several forms of retinal screening with standard fundus photography or digital imaging, with and without dilation, are being investigated as a means of detecting retinopathy.
Appropriately validated digital imaging technology can be a sensitive and effective screening tool to identify patients with diabetic retinopathy for referral for ophthalmic evaluation and management. Digital cameras with stereoscopic capabilities are useful for identifying subtle neovascularization and macular edema. At this time, it is not clear that photographic screening programs achieve a greater reduction in vision loss than does routine community care in areas where access to ophthalmologists is straightforward.
At this time, these technologies are not considered a replacement for a comprehensive eye evaluation by an ophthalmologist experienced in managing diabetic retinopathy. Furthermore, an ophthalmologists, also can play an important role in the total care of the patient with diabetes. For example, at the time of the eye examination, patients can be counseled about the importance of blood glucose and blood pressure control.
But, the problems most of diabetic patients doesn't know when to find an opthalmologist since they doesn't any changes in visions. Current recommendation stated that annual eye examination is needed for the patients that having diabetes at least 5 years.
The development and progression of diabetic retinopathy in patients with type 1 diabetes can be delayed if glucose concentrations are maintained in the near-normal range. Strict glucose control also resulted in a 50% reduction in the rate of progression of retinopathy in patients with existing retinopathy. At the 6- and 12-month visits, a small number of patients had a transient early worsening of the retinopathy in the intensive treatment group, but there was no effect on visual acuity.
In patients with newly diagnosed type 2 diabetes. Intensive blood glucose control by either the sulfonylureas or insulin decreased the risk of microvascular complications but not the risk of macrovascular disease. There were no adverse effects of the individual drugs on the cardiovascular outcome. In this study, there was a 29% reduction in the need for retinal photocoagulation surgery in the group with intensive glucose therapy compared with those receiving conventional treatment.
Conclusion
It is important to educate all patients who have diabetes about the disease and to emphasize the value of maintaining blood glucose (as monitored by hemoglobin A1c) as near normal as is safely possible. The studies have shown that lowering blood glucose reduces other end-organ complications as well, including nephropathy and neuropathy and cardiovascular disease.
