biomicroscope but are not judged to be the cause of his recent vision loss. Older patients often may believe that vision loss is an inevitable symptom of aging rather than ascribing a specific diagnosis, such as diabetes, as the cause of visual impairment. While vision loss may become more common with age, older patients should realize that aging, in and of itself, is not a cause of vision loss. Rather, specific diagnoses, including diabetic retinopathy may become more prevalent with older age and are potential reasons for vision loss. Older patients should not just accept vision loss as an inevitable sign of aging but should pursue with an ophthalmologist what the cause of vision loss is, especially since most incidents of vision loss in older people can be treated. This is especially true for all older patients with diabetes to understand, even at a time when diabetes has been diagnosed but there is no diabetic retinopathy.

The patient also may not realize that features of diabetic retinopathy, such as macular edema, which can cause vision loss, may be present before any vision loss has occurred, but that vision loss can be prevented in such cases if focal/grid photocoagulation is initiated when the center of the macula is thickened or when edema appears to be encroaching on the center of the macula.5

Management of Diabetic Retinopathy in Older People: Medical Knowledge and Patient Care

The management of diabetic retinopathy in older people includes the management of two processes: (1) diabetic macular edema and (2) level of retinopathy.

Management of Diabetic Macular Edema

Macular edema represents a thickening of the retina due to intercellular and occasionally subretinal accumulation of edema. Presumably, loss of pericytes and capillary nonperfusion due to elevated blood sugar levels can lead to the development of microaneurysms and retinal telangiectasis which may allow intercellular fluid to accumulate, most easily within the outer plexiform retina, then throughout the retina, and even into the subretinal space. The edema is recognized clinically as an increased distance of the surface of the retina from the retinal pigment epithelium or by documentation of this thickening on OCT imaging.

The management of DME includes counseling or reinforcing the need to maintain blood glucose levels to as near normal levels as is possible, balanced by the risks of such treatment to achieve these levels, and doing so in a way that will encourage the older patient to recognize that managing diabetes can impact the maintenance of vision. Communication with the older patient’s primary care provider or whoever is managing the patient’s diabetes care or both is essential. Diabetes can involve so many specialists and the coordination of this care can be challenging for any patient. For the older patient, this coordination can be even more challenging when additional comorbidities unrelated to diabetes also

may be present. Attention to blood pressure and lipid control should be done in anyone, but a patient with diabetes can be reminded by the ophthalmologist that maintaining care of blood pressure and lipids may be associated with less diabetic retinopathy and vision loss.

The initial workup for a patient suspected of having diabetic macular edema should consist of a detailed history including any onset of metamorphopsia presumably from diabetic macular edema, or central scotoma potentially from capillary nonperfusion in the macula leading to edema. Ocular history regarding past laser treatments or intravitreal treatments should be elicited, along with kidney disease (which could exacerbate edema) and use of drugs that might be associated with edema.

Practice-Based Learning

The ophthalmological examination, as described in the AAO’s Preferred Practice Pattern for Diabetic Retinopathy, should include an evaluation of visual acuity along with stereoscopic biomicroscopic examination of the macula and, if macular edema is suspected, OCT and fluorescein angiography might be obtained. OCT could provide objective quantification of the edema for comparison to future visits in order to determine whether persistent edema following treatment represents improved but persistent edema or worsening of edema (Fig. 2). Fluorescein angiography can facilitate placement of laser treatment directly (focally) to microaneurysms within areas of thickening by highlighting microaneurysms (Fig. 3), as well as placement in a grid (macular scatter) pattern to thickened areas of diffuse fluorescein leakage, and considering not placing grid to thickened areas of capillary nonperfusion. The angiogram also might identify small areas of retinal neovascularization not detected on clinical examination (see next section of proliferative diabetic retinopathy); to detect these areas, the ophthalmic photographer should consider taking images which sweep fields outside of the disc and macula (see next section on neovascular AMD).

Macular edema usually is treated if it involves the fovea or is threatening the fovea (i.e., associated with lipid in the fovea, or extending toward the fovea, e.g., extending within 500 microns of the foveal center or a large area of edema within 1500 microns of the foveal center and documented to be progressing toward the foveal center). Treatment consists of focal/grid photocoagulation; focal (direct) laser treatment to microaneurysms within thickened retina and grid (macular scatter) laser within other areas of thickened retina. The Early Treatment Diabetic Retinopathy Study (ETDRS) demonstrated that such treatment can reduce the risk of at least moderate vision loss from 30% without treatment to 15% with treatment when the center of the retina is edematous or threatened to become edematous.5 Most of the cases enrolled in the ETDRS, though, had visual acuity better than a Snellen equivalent of 20/40. The Diabetic Retinopathy Clinical Research Network (DRCR.net) subsequently demonstrated that focal/grid laser was superior to intravitreal corticosteroid