Kembara Xtra - Medicine - Diabetic Retinopathy

Kembara Xtra - Medicine - Diabetic Retinopathy
A retinal condition that does not cause inflammation and is characterized by capillary closure in the retina and microaneurysms. Ischemia of the retina causes the release of a vasoproliferative factor, which stimulates the growth of new blood vessels on the retina, optic nerve, or iris.
Patients who have diabetes mellitus (DM) will, in almost all cases, go on to acquire diabetic retinopathy (DR). It is the largest cause of new cases of legal blindness among residents of the United States aged 20 to 64 years old, making it the top cause of new blindness cases overall.
 The DR process can be broken down into three stages:
– Nonproliferative (NPDR) (background) – Severe (NPDR) (preproliferative) – Proliferative (PDR)


It is possible for the problem to become worse during pregnancy.
Examinations of diabetic pregnant women should begin in the first trimester and continue at regular intervals of three months till delivery.



 The peak age range for the emergence of type 1 diabetes in adolescents is between the ages of 12 and 15 years. Insulin insufficiency is caused by the death of beta cells, which occurs in type 1 diabetes (T1DM).
 The age range of 50–70 years old is when the risk of developing type 2 diabetes in adults is at its highest. Diabetes type 2 (T2DM) can range from a condition that is defined by insulin resistance with relative insulin insufficiency to one that is largely an insulin secretory defect with insulin resistance. Insulin resistance is one of the hallmarks of diabetes type 2 (T2DM).
 The duration of diabetes is directly connected to the incidence of diabetic retinopathy.
It is extremely rare to see DR in children younger than 10 years old.
 Diabetes mellitus affects approximately 13.0% of all persons in the United States who are 18 years or older.
The prevalence rises with age, reaching 26.8% of persons in the United States who are aged 65 and older.
 Diabetic retinopathy affects one in every three people who have diabetes across the world.
 The most common age: - The risk rises following the onset of puberty.
– PDR will occur in two-thirds of type 1 diabetic people who have had diabetes for at least 35 years, and diabetic macular edema (DME) will develop in one-third of these patients.
 Females outnumber males with type 1 diabetes, while males are more likely to have type 2 diabetes.


Etiology and Pathophysiology
Associated with the development of diabetic microaneurysms and microvascular anomalies.
Reduced perifoveal capillary blood flow velocity, occluded perifoveal capillaries, and increased retinal thickness at the central fovea in diabetic patients are all factors that have been linked to visual impairment in patients with diabetic macular edema (DME).
Patients who have hypoxic retina have higher levels of vascular endothelial growth factor, also known as VEGF. Patients who have NV in either the retina or the iris have increased amounts of VEGF within the eye. DME is also caused by a lack of oxygen in the retina, and VEGF is one of the most important causes of DME.


Risk Factors
• Poor glycemic control • Prolonged duration of diabetes (often more than ten years) • Pregnancy • Renal disease
 Systemic hypertension (also known as HTN); Elevated cholesterol levels; Cigarette smoking
 People who have myopic eyes, which have a longer axial length than other eyes, have a lower chance of acquiring DR and of the progression of the disease.


Prevention
It is important to keep a close check on your blood sugar levels and take steps to bring them under control.


Associated Conditions
Glaucoma, cataracts,retinal detachment
,vitreous hemorrhage (VH); Disc edema (diabetic papillopathy); both types of diabetes can cause these complications.


Diagnosis 

 During the eye exam, a measurement of the patient's visual acuity and examining of the patient's iris, lens, vitreous, and fundus will be performed. NPDR (context) will also be reviewed.
- Microaneurysm
- Bleeding inside the retinal blood vessels
- Depositions of lipids
• Severe NPDR (preproliferative) - Infarctions of the nerve fiber layer (also known as "cotton wool spots");
– Beading of the venous system – Dilatation of the venous system – Intraretinal microvascular abnormalities (IRMA)
.A significant amount of bleeding in the retina
– The 4:2:1 rule was created by the Early Treatment Diabetic Retinopathy Study (ETDRS). It is used to diagnose severe cases of nonproliferative diabetic retinopathy (NPDR). To be diagnosed with severe NPDR, a patient must exhibit at least one of the following characteristics:
 Severe hemorrhages and microaneurysms inside the retina, distributed evenly across all four quadrants
,beading of the venous system in two or more quadrants
IRMAs in at least one of the four quadrants
 
PDR - Proliferation of new blood vessels (NV): NV can be observed on the surface of the retina, on the optic nerve, and on the iris.
- Loss of vision brought on by vitreomacular traction retinal detachment (VH).
It is possible for vitreous hemorrhage and traction retinal detachment to result from the contraction of fibrovascular tissue on a vitreous scaffold.


Differential Diagnosis 
Other risk factors for developing retinopathy include high blood pressure, radiation exposure, and obstruction of the retinal veins.


Laboratory Findings
Fluorescein angiography is able to demonstrate retinal nonperfusion, retinal leakage, and PDR during diagnostic procedures and other procedures.
OCT, which stands for optical coherence tomography, can be utilized to aid in the diagnosis of DME by evaluating the thickness of the retina.
 Diabetic neovascularization (NV) can be detected using swept-source optical coherence tomography angiography (SS-OCTA).


Management
The Diabetes Control and Complications Trial (DCCT) indicated that blood glucose levels should be as close to the nondiabetic range as is safe for the majority of patients with type 1 diabetes who also had insulin-dependent diabetes in order to lower the risk and rate of progression of diabetic retinopathy (DR).
– Patients with insulin-dependent Type 1 Diabetes who participated in the DCCT were given a treatment regimen at random, either one of two types: standard or intensive. The DCCT showed that intensive insulin therapy lowered the incidence of both diabetic macular edema and retinal neovascularization. The lowered risk of DR-associated microvascular problems that comes with rigorous insulin therapy is a benefit that lasts for at least ten years after treatment has stopped.
– The DCCT found that intensive insulin therapy was more beneficial in lowering the likelihood of progression of diabetes-related complications in earlier stages of the disease. Nevertheless, even patients with severe DR benefited from the intense insulin treatment.
The United Kingdom Prospective Diabetes Study (UKPDS) found that patients with type 2 diabetes who maintained strict control of their blood glucose levels had a slower progression of diabetic retinopathy. In addition, it demonstrated that strict regulation of blood pressure slowed down the development of DR.
 A blood sugar level of less than 200 mg/dL is associated with an increased risk of microvascular consequences, including PDR.
Cataracts are more likely in those who have diabetes mellitus.
It is possible for cataract surgery to make retinopathy worse and to raise the chance of developing diabetic macular edema (DME).
Controlling hypertension is necessary because it has a negative impact on DR.
Patients who have type 2 diabetes are more likely to develop diabetic microvascular complications if they have severe obstructive sleep apnea (OSA). Patients who have severe OSA have a greater risk of developing refractory DME. Patients diagnosed with OSA and using continuous positive airway pressure (CPAP) may have a lower risk of developing refractory DME.



Medication
It has been demonstrated that the treatment of hypertension with the angiotensin receptor blocker candesartan can result in the reversal of DR in certain people.
 The use of statin medication in persons diagnosed with type 2 diabetes is connected with a reduced incidence of DR:
— Patients with type 2 diabetes who use drugs to reduce their lipid levels have a lower risk of developing NPDR, PDR, or DME.
 The use of aspirin does not slow the progression of DR and does not increase the risk of vascular heart surgery or other procedures.
 The use of intravitreal aflibercept injection (IAI) as a preventative treatment for moderate to severe NPDR in patients who did not have centered-involved diabetic macular edema (CI-DME) led to a reduction in the development of PDR or vision-reducing CI-DME. When compared with observation with IAI only after the onset of PDR or vision-reducing CI-DME, preventive therapy with IAI did not give VA benefit after 2 years of follow-up.
Intravitreal anti-VEGF therapy is the recommended first-line treatment for diabetic macular edema (DME).
When administered intravitreally, the antibody fragment ranibizumab, which binds VEGF, can be used to treat diabetic macular edema (DME).
Vision was improved with ranibizumab injections of 0.3 mg (0.05 mL) given intravitreally on a monthly basis, and the thickness of the central fovea was decreased.
When compared to treatment with laser photocoagulation for diabetic macular edema (DME), anti-VEGF therapy administered via intravitreal injection (IVI) yields improved clinical outcomes.
Patients who have diabetic macular edema and concomitant retinal nonperfusion can benefit from intravitreal ranibizumab injections, also known as IRIs.
It is possible that IRI for DME will improve the severity of DR as well as lower the risk of DR progression.
When compared with dosing on a monthly basis for one year, the IRI treatment plan known as "treat and extend dosing" resulted in fewer injections while producing visually and anatomically equivalent effects.
Treatment on as-needed basis following a loading dosage of three monthly injections has been demonstrated to produce outcomes that are comparable to treatments administered more often.
Prophylaxis with topical povidone-iodine is essential for helping to prevent endophthalmitis caused by IVIs that are caused by treatment with anti-VEGF.
○ When injected intravitreally, the full-length antibody bevacizumab, which binds VEGF, can be used to treat diabetic macular edema (DME).
An unapproved usage of bevacizumab is intravitreal injection (also known as IBI).
 Aflibercept is a decoy receptor for the VEGF protein, and it suppresses all isoforms of VEGF-A as well as placental growth factor.
After the initial five injections of aflibercept at a frequency of 2 mg (0.05 mL) injected intravitreally every 4 weeks, subsequent injections are administered at a frequency of 2 mg (0.05 mL) injected intravitreally once every 8 weeks. It is prescribed to people who have DME as well as patients who have DR but do not have DME.
The intravitreal injection of aflibercept, also known as IAI, has been shown to be significantly superior to macular laser photocoagulation in terms of both functional and anatomic end objectives.
 At worse levels of initial visual acuity (VA) (20/50 or worse), IAI was more successful in improving vision than ranibizumab or bevacizumab with 1-year follow-up in patients with DME who had diabetic macular edema (DME). In patients with DME, there was no significant difference between aflibercept, ranibizumab, and bevacizumab when the initial vision loss was minor (20/32 to 20/40). However, aflibercept had superior 2-year VA results compared with bevacizumab. After two years of follow-up, the superiority of aflibercept over ranibizumab, which had been shown after one year, was no longer visible.
There was no significant difference in vision loss between eyes that were initially handled with observation plus IAI only if VA declined, initial focal laser treatment plus IAI only if VA decreased, or prompt IAI among eyes that had CI-DME and good VA (20/25 or better). This was the case whether the eyes were managed with observation plus IAI only if VA decreased, initial focal laser treatment plus IAI only if VA decreased, or prompt IAI. When dealing with CI-DME, it is possible that a reasonable course of action would be to observe the patient without providing treatment unless the VA worsens.
It has been demonstrated that IAI on  as-needed basis can preserve vision and cut down on the number of treatments required.
Angiopoietin-2 and VEGF-A are both inhibited by the use of the drug faricimab. A dose schedule of once every four months is now under investigation for the treatment of DME.
- Treatment with a focal laser.
Vitrectomy is an option for patients who have been diagnosed with diffuse macular edema. This may be especially relevant for eyes that have been identified to have vitreomacular tension on OCT and also have persistent DME.
– Intravitreal triamcinolone may be used for diabetic macular edema in individuals who have not responded to laser treatment; however, there is no long-term advantage of intravitreal triamcinolone in comparison to focal or grid photocoagulation in patients who have DME.
- Steroid implants placed intraocularly for the treatment of DME. Either a fluocinolone acetonide implant or a dexamethasone implant would be appropriate. Cataracts and glaucoma are two eye conditions that can be caused by these implants.
 The treatment for PDR is as follows: – One typical method of treating PDR is called thermal laser photocoagulation, which is performed in a pattern that covers the entire retina. Regression or involution of NV is the desired outcome of panretinal photocoagulation, often known as PRP. PRP is responsible for the destruction of ischemic retina and a reduction in the neovascular stimulation.
When platelet-rich plasma (PRP) was used to treat proliferative diabetic retinopathy (PDR) or severe nonproliferative diabetic retinopathy (NPDR), the Diabetic Retinopathy Study found that eyes treated with PRP had a reduction of 50% or more in the rates of severe vision loss when compared with untreated control eyes. At two years, the frequency of significant vision loss in eyes that had not been treated was as high as 36.9% in specific categories.
Patients diagnosed with DME and a high-risk proliferative condition are candidates for concurrent focused and PRP treatment, which does not compromise the patients' ability to see.
– Alternative treatments for PDR include PRP, as well as IRI, IAI, and others.
In the treatment of PDR, they can be utilized in conjunction with PRP.
– Initial intravitreal immunotherapy (IAI) or pars plana vitrectomy (PPV) with platelet-rich plasma (PRP) can be utilized to treat VH caused by PDR (6)[A].
– There is no evidence that intravenous administration of anti-VEGF medication for PDR is associated with an increased risk of TRD [B].
- Patients who have severe PDR, traction retinal detachment including the macula, and nonclearing VH might consider PPV:
The Diabetic Retinopathy Vitrectomy Study (DRVS) established the benefits of early PPV (1 to 6 months after development of VH) in T1DM and for eyes with extremely severe PDR. Immediate PPV with endolaser may be explored for PDR-associated VH that has lasted less than 30 days.
When complications of PDR arise, preoperative IBI may be used as an adjuvant to vitrectomy to treat the condition. This is an unapproved use of the product.
Medicine that is both complementary and alternative
The consumption of nutritional antioxidants such as vitamins C and E as well as beta-carotene does not offer any protection against 


Recommendation and Continuous Care

Patient Monitoring 
Ophthalmologic eye exams that are on the schedule
Follow-up once a year if there is no retinopathy; once every six months if there is background DR; once every three to four months at the very least if there is pre-PDR; once every two to three months if there is active PDR; patients with DME should be observed every four to six weeks.


Diet
The consumption of at least 500 mg per day of dietary long-chain omega-3 polyunsaturated fatty acids, which can be attained by consuming two weekly portions of oily fish, is associated with a lower risk of vision loss due to diabetic retinopathy in adults who are middle-aged or older and have type 2 diabetes.

Patient Education - Suggest that they get their eyes checked on a regular basis.
 f Maintaining proper glucose control with a combination of food, exercise, and medication or insulin.

Prognosis
The prognosis is favorable if the illness is detected and treated at an early stage in its progression. If treatment is delayed, there is a risk of blindness occurring.

Complications
● Repeated intravitreal injection of anti-VEGF therapy may increase the risk of sustained intraocular pressure elevation and the possible need for ocular hypotensive treatment.
● Blindness

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