Diabetes mellitus (DM) is a disease that affects a person's ability to metabolize sugars. A patient suffering from DM will present with numerous symptoms including hyperglycemia, polyuria, polydipsia, polyphagia, and blurred vision. Additionally, patients typically experience yeast infections more often than patients without DM. Although patients may experience all or some of these symptoms, they will often be unaware of the condition until it is diagnosed by a doctor. If a patient's blood glucose level remains elevated for a long period of time due to poor adherence to prescribed medications and diet, complications such as diabetic retinopathy, hypertension, neuropathy, and increased foot infections may occur. Therefore, it is incredibly important for patients to monitor their blood glucose levels at home. This provides patients with key information to adjust medication levels and restrict diet based on the latest values. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essayDM consists of two main types: type 1 and type 2. Type 1 is caused by the destruction of the beta cells of the pancreas, which produce insulin. It represents approximately 10% of DM and is believed to be an autoimmune process. Type 2 is due to a combination of insulin resistance and inadequate insulin production by the pancreas. It represents approximately 90% of the DM. DM is diagnosed if one of the following conditions is met: an HbA1c level of 6.5% or greater, a fasting plasma glucose level of 126 mg/dl or greater, a 2-hour plasma glucose level of at 200 mg/dl or higher or a random plasma glucose reading of 200 mg/dl or higher. HbA1c measures the glucose level in a patient's blood by measuring the percentage of hemoglobin that binds glucose. Glucose does not typically bind to hemoglobin, but when a patient has hyperglycemia, more glucose binds to hemoglobin. This measurement is preferred because it is an average reading over a period of a few months rather than a one-time measurement like other diagnostic tests. According to the American Diabetes Association, in 2015, 9.4% (30.3 million) of the US population had diabetes. Of that 9.4%, approximately 24% (12 million) patients were undiagnosed. About 25.2% of people over 65 suffer from diabetes, while only 0.24% of people under 20 suffer from diabetes. Diabetes is more common among American Indians, blacks, and Hispanics in the United States. On a global scale, approximately 422 million people suffer from diabetes. This equates to an increase of nearly 4% since 1980. The prevalence of diabetes varies greatly around the world, but higher rates of type 1 diabetes are found in European countries, followed closely by Canada and the United States. Type 2 diabetes shows higher rates among the groups discussed above in the United States, as well as in Fiji, China, and South Africa. Patients are at greater risk of developing diabetes if they have any of the following characteristics: are overweight, are over 45 years of age, are American Indian, Black, Hispanic, or Pacific Islander, have hypertension, are not physically active, have a family history of diabetes, etc. Diabetes rates are rising rapidly in countries that are adopting a lifestyle similar to that of the United States. More and more people are becoming obese, leading to more patients being diagnosed with type 2 diabetes. A person's BMI is used as an indicator to determine whether a patient is overweight or obese. BMI stands forbody mass index and is equal to the patient's weight in kilograms divided by his height in meters squared. A BMI of 27.3 or more is considered overweight, while a BMI of 30 or more is considered obese. Although some muscular patients may experience a superficially elevated BMI, it is still considered a good indicator of a person's healthy weight. One of the major concerns in patients who have had diabetes for a long period of time is the development of diabetic retinopathy (DR). Approximately 93 million people worldwide suffer from DR. The incidence of DR varies greatly around the world, but on average 30-40% of patients with DM will develop DR. There are many risk factors for developing DR, including: the length of time the patient has had diabetes, males are at higher risk than females, hypertension, high HbA1c levels, smoking, puberty increases rates in patients with type 1 diabetes, pregnancy, as well as kidney damage can cause an increased risk of developing DR. DR occurs due to the impact of various pathways in the body by increased glucose levels. The polyol pathway reduces excess glucose in the retina to sorbitol and then to fructose. The conversion of sorbitol to fructose is slow and this leads to sorbitol becoming trapped in retinal cells. This creates osmotic damage in the cells of the retina as the water follows its concentration gradient. This may also produce a myopic shift due to the lens becoming less flexible in young patients or may lead to a higher refractive index in patients without accommodation. Because water regulation is affected, patients may often experience dry eye symptoms as well. This pathway has also been linked to increased thickness of the basement membrane of retinal capillaries. Hyperglycemia also leads to increased protein kinase C activation which results in changes in retinal hemodynamics, vascular endothelial growth factor (VEGF) expression, and endothelial permeability. This can lead to oxidative stress and macular edema. Macular edema causes the photoreceptors to misorientate, resulting in vision problems. Ischemia leads to the recruitment of VEGF which causes neovascularization to bring more oxygen to the hypoxic area. Neovascularization leads to the formation of fragile and leaky blood vessels. VEGF is also believed to control the actions of insulin growth factor 1 (IGF1); however, the role of IGF1 in DR is currently not fully understood. When the contents of the vessels penetrate the vitreous, vision is negatively affected. Iris neovascularization can also lead to open-angle glaucoma due to hypoxic conditions created by changes in the vasculature. Hypertension also causes endothelial damage. Therefore, many pathways contribute to the development of DR, and a cure would be very difficult to achieve. The two main types of DR are proliferative DR (PDR) and nonproliferative DR (NPDR), which can be further divided into mild, moderate, and severe categories. In mild NPDR, microaneurysms occur. Microaneurysms are small areas of blood vessels that become weak due to pericyte and balloon leakage to the outside. In moderate NPDR, microaneurysms, punctate hemorrhages, and scattered exudates occur. In severe NPDR, spot and flame hemorrhages, cotton wool stains, hard exudates, and obvious venous relief occur, but no signs of PDR are present. Spot and spot hemorrhages are micro aneurysms that have ruptured in the inner and outer plexiform layers. Hard exudates consist oflipids leaked from retinal capillaries once weakened. These exudates appear yellow and are typically found around the macula, which can lead to vision problems. Cotton wool spots are caused by ischemia of the retinal vessels leading to infarction of the nerve fiber layer of the retina. These spots appear white and soft when looking at the retina. In PDR, retinal ischemia leads to the formation of new leaky blood vessels. Patients with PDR may present with vitreous hemorrhages, neovascularization near the optic disc, and beading and kinking of the vasculature due to hypoxic conditions of the retina. PDR can lead to tractional retinal detachments and blindness. This occurs when new blood vessels created by VEGF use the vitreous as a scaffold. When the vessels attach to the vitreous, when the eye moves, the retina undergoes traction and retinal detachments can occur. It is important for a patient with diabetes to undergo annual exams to prevent NPDR from turning into PDRil for as long as possible. Many factors of DR cause vision loss, some of which include: macular edema causing misorientation of photoreceptors, leakage of vascular contents into the vitreous due to neovascularization, and hard yellow exudates centered around the macula and optic nerve head. The most likely cause of vision loss in both eyes of this patient would be macular edema. This diagnosis could be confirmed using various imaging techniques and tests such as retinal imaging, fundus photography, and optical coherence tomography (OCT). Retinal imaging simply takes a photo of the retina. Fundus photography requires the patient to be dilated, so the retina can be visualized. OCT can provide cross sections of the retina that can provide information on exactly how much edema is present in a given area, where a detachment has occurred, where a retinal hemorrhage is located, etc. The information from the OCT allows the doctor to determine how aggressive the treatment should be for a particular patient. Fluorescein angiography may also be performed to determine the location of blocked or leaky retinal veins or arteries. First the patient would be dilated and baseline photos of the retina would be taken. Next, the NaFl dye is injected into the patient's vein. NaFl dye can have negative side effects such as nausea, vomiting, and hot flashes, so it is best to inform the patient of these potential side effects before starting the procedure. Finally, the examiner should start taking photos. The dye travels from the patient's arm where it is injected to the patient's eye where it first reaches the choriocapillary vessels. Because the choriocapillaris is fenestrated, the dye is visible as an irregular background glow in the choroidal wash phase. This only takes 10-15 seconds to occur. Next, the central arteries fill rapidly, followed by the peripheral arteries, then the capillaries, followed by the peripheral veins, and finally the central veins. The dye should remain within these vessels, but if the vasculature is damaged, as in DR, fluorescein may be seen leaking from the vessels. Similarly, if a vessel is blocked, vessel filling will not occur as previously described and a blockage would be easily identified using this technique. Finally, in the late phase, the choriocapillaris, arteries and veins drain the dye. The dye causes the head of the optic nerve to glow as it exits the eye. This phase occurs approximately 10 minutes after the dye is injected. There are several treatment options forDR, including pan retinal photocoagulation (PRP). In PRP, an argon laser is used to create 1200-1800, 200-500 micron burns across the retina. These burns cause coagulative necrosis of leaky blood vessels. Since no oxygen is needed in this area of ​​the retina after the burn, the rest of the retina receives better oxygenation. This treatment has been shown to be incredibly effective, but it can also cause complications such as wet retinal detachment, macular edema, visual field defects, and night vision defects, so patients should be aware of other treatment options besides PRP. A somewhat similar treatment, focal laser treatment, exists for macular edema. This laser treatment is used to create 50-100 micron burns on leaky blood vessels. This allows the inner retina to better utilize oxygen in a similar way to PRP. This treatment has been shown to reduce the patient's risk of loss of visual acuity by 50%. Other treatment options are also available for patients with DR. One such treatment option is Avastin. Avastin is administered via intravitreal injections into the eye and binds to the receptor-binding domain of VEGF-A, which prevents VEGF-A from interacting with its receptor; therefore it does not signal the formation of new leaky blood vessels. There are also similar drugs on the market, including Lucentis and Eylea. Since VEGF is blocked, macular edema would be reduced leading to better visual acuity for patients. One study found that over the course of 5 years Avastina injections stabilized or improved visual acuity in 70% of cases. PRP should also be considered with injections as it is more likely to provide better long-term control of the patient's symptoms. Although this treatment has been shown to be highly effective, it is important to inform the patient of the possible risks associated with these injections. The greatest risk is the development of infections, including endophthalmitis, which can lead to the loss of the patient's eye. Since in this case the patient has blood in the vitreous, ultrasound can be used to determine whether a retinal or vitreous detachment is present. B-scan ultrasound is a noninvasive procedure that uses a probe and sound waves to produce a 2D grid of black and white dots. Black dots correspond to areas of poorly reflective interfaces while white dots correspond to highly reflective interfaces. If the results show no retinal detachment, but there is blood in the vitreous, you may need to perform a vitrectomy. A vitrectomy removes the vitreous gel to which new blood vessels have attached in DR. Removing this gel will prevent additional tensile forces from acting on the retina and decrease the chance of retinal detachment. Once the vitreous gel is removed, a bubble of gas or oil is used to hold the retina in place. Eventually the body will produce fluids that will replace the blister and can be removed with a second surgery. Please note: this is just a sample. Get a custom paper from our expert writers now. Get a Custom Essay Overall, diabetes is a rather complicated condition that affects many organ systems within the body including the eye. It is important for patients to effectively manage their blood sugar levels in order to reduce damage done to the vascular system and organs. If diabetes remains uncontrolled, eye health can suffer greatly and cause complications such as macular edema and DR. It is important that patients are well informed about the possible repercussions of the disease. Although not currently,.