Diagnosis of Ocular Manifestations of Diabetes Mellitus
The first diagnosis of the patient who is unaware of having a diabetic condition may be based on an eye examination. Ocular examination of a patient suspected of having undiagnosed diabetes mellitus (DM) should include all aspects of a comprehensive eye examination. Particular attention should be paid to the ocular and systemic signs and symptoms of DM, as discussed in this section.
Patients with DM need regular eye examinations. The examination should include all aspects of a comprehensive eye examination, with supplementary testing as indicated to detect and thoroughly evaluate ocular complications. The frequency of examination is determined on the basis of several factors, including the type of DM, duration of the disease, age of the patient, level of patient compliance, concurrent medical status, and both nonretinal and retinal ocular findings. Due to the risk for progression diabetic retinopathy (DR) during pregnancy, a diabetic woman should have a baseline examination prior to a planned pregnancy or early in the first trimester of pregnancy.
Components of patient care, discussed in greater detail in the guideline document, include the following:
- Patient history
- Ocular examination
- Best corrected visual acuity
- Pupillary reflexes
- Ocular motility
- Visual field screening
- Refraction
- Biomicroscopy
- Tonometry
- Stereoscopic fundus examination with pupillary dilation
- Examination technique
- Supplemental testing
- Color vision assessment
- Contrast sensitivity testing
- Fundus photography or validated retinal imaging
- Gonioscopy
- Macular function assessment
Management of Ocular Manifestations of Diabetes Mellitus
Treatment decisions depend upon the extent and severity of the patient's ocular condition.
- Patients with Undiagnosed Diabetes Mellitus
Patients suspected of having diabetes mellitus (DM) should be screened for high blood glucose levels. The optometrist should refer the patient to a physician for evaluation or request a fasting blood glucose analysis. Patients with fasting blood glucose values of greater than or equal to 110 mg/dL but less than 126 mg/dL have impaired fasting glucose (IFG) and should be retested. All patients with fasting blood glucose values of 126 mg/dL or greater should be referred to physicians for further evaluation or treatment. Most pregnant women should be screened for glucose intolerance. Because a pregnant patient is usually under medical care, her obstetrician should coordinate this examination.
- Patients with Nonretinal Ocular Complications
Management of nonretinal ocular complications of diabetes mellitus should be consistent with current recommendations of care for each condition. The management of nonretinal ocular complications of diabetes mellitus is briefly outlined in the following table. Treatment protocols should always include patient education and recommendations for follow-up visits.
Management of Nonretinal Ocular Complications of Diabetes Mellitus
Category |
Ocular Complications |
Management* |
Functional |
Tritan color vision loss
| Dilated fundus examination to rule out diabetic maculopathy; counseling; low vision evaluation; review of independent living aids as necessary |
Refractive error changes
Accommodative dysfunction |
Consultation with patient's physician regarding degree of blood glucose control; modification of spectacle prescription as necessary |
Visual field defects |
Low vision evaluation; orientation and mobility training as necessary |
Extraocular Muscle Anomalies |
Mononeuropathies |
Neuro-ophthalmology or neurology consultation; temporary prism spectacle prescription as needed; eye patching as indicated |
Pupils |
Sluggish pupillary reflexes
Afferent pupillary defects |
Workup to rule out optic neuropathy |
Conjunctiva |
Bulbar microaneurysms |
Monitoring |
Tear Film |
Dry eye syndrome |
Prescription of artificial tears, ocular lubricants, and other dry eye management techniques; monitoring for corneal complications |
Cornea |
Reduced corneal sensitivity |
Monitoring for abrasions, keratitis, or other ulcerations |
Basement membrane anomalies, recurrent corneal erosions |
Prescription of NaCl solution/ointment; artificial tears; patching as necessary |
Descemet's membrane wrinkling |
Monitoring |
Endothelial cell changes |
Monitoring
Note: All corneal injuries should be monitored carefully for secondary infection or evidence of delayed wound healing. This is particularly important in patients who wear contact lenses. |
Iris |
Depigmentation |
Monitoring; routine gonioscopy and tonometry |
Rubeosis iridis (neovascularization on the iris) |
Gonioscopy to rule out anterior chamber angle involvement and neovascular glaucoma; dilated fundus examination to search for proliferative retinopathy; referral to retinal specialist for possible laser surgery |
Lens |
Cataracts |
Monitoring of both degree of lens opacification and status of any retinopathy; cataract extraction after careful preoperative retinal evaluation; surgery indicated if adequate visualization of the retina is no longer possible |
Vitreous |
Hemorrhage |
Dilated fundus examination; consultation with retina specialist |
*Patient education is an integral part of management for all conditions.
- Patients with Retinal Complications
When indicated (generally for levels of moderate nonproliferative diabetic retinopathy [NPDR] or worse, any proliferative diabetic retinopathy [PDR], any macular edema, neovascularization of the iris, or unexplained vision loss), the optometrist should refer the DM patients to an ophthalmologist skilled in treating diseases of the retina or a retina specialist.
Available treatment options, management and follow-up for nonproliferative diabetic retinopathy, proliferative diabetic retinopathy and macular edema are discussed in greater detail in the guideline document.
Patient education is an important component of care because virtually all patients with diabetes mellitus will develop some form of diabetic retinopathy at some point during the course of the disease.
Diabetic patients who do not have diabetic retinopathy should be reexamined annually. The follow-up examination of patients with diabetic retinopathy should be scheduled in accordance with the clinical trial protocols. The frequency and composition of evaluation and management visits for retinal complications of diabetes mellitus are summarized in the following table:
Frequency and Composition of Evaluation and Management Visits for Retinal Complications of Diabetes Mellitus
|
Natural Course Rate to Progression to: |
|
Composition of Follow-Up Evaluations |
Management Plan* |
Severity of Condition |
PDR
1 year |
HRC
5 years |
Frequency of Follow-Up |
Fundus Photography |
Fluorescein Angiography |
Referral for Consultation and/or Treatment |
Scatter Laser Treatment |
Focal Laser Treatment |
Mild NPDR |
5% |
15% |
|
|
|
|
|
|
No macular edema |
|
|
12 mos |
No |
No |
Communicate with patient's physician |
No |
No |
Macular edema |
|
|
4 to 6 mos |
Yes |
Occ. |
Obtain retinal consult in 2 to 4 weeks |
No |
No |
CSME |
|
|
2 to 4 mos |
Yes |
Yes |
Obtain retinal consult in 2 to 4 weeks |
No |
Yes |
Moderate NPDR |
12 to 27% |
33% |
|
|
|
|
|
|
No macular edema |
|
|
6 to 8 mos |
Yes |
No |
Communicate with patient's physician |
No |
No |
Macular edema (not CSME) |
|
|
4 to 6 mos |
Yes |
Occ. |
Obtain retinal consult in 2 to 4 weeks |
No |
No |
CSME |
|
|
2 to 4 mos |
Yes |
Yes |
Obtain retinal consult in 2 to 4 weeks |
No |
Yes |
Severe NPDR |
52% |
60 to 75% |
|
|
|
|
|
|
No macular edema |
|
|
3 to 4 mos |
Yes |
No |
Obtain retinal consult in 2 to 4 wks |
Rarely** |
No |
Macular edema (not CSME) |
|
|
2 to 3 mos |
Yes |
Occ. |
Obtain retinal consult in 2 to 4 wks |
Occ. after focal** |
Occ. |
CSME |
|
|
2 to 3 mos |
Yes |
Yes |
Obtain retinal consult in 2 to 4 wks |
Occ. after focal** |
Yes |
Non-high-risk PDR |
|
75% |
|
|
|
|
|
|
No macular edema |
|
|
2 to 3 mos |
Yes |
No |
Obtain retinal consult in 2 to 4 wks |
Occ.*** |
No |
Macular edema |
|
|
2 to 3 mos |
Yes |
Occ. |
Obtain retinal consult in 2 to 4 wks |
Occ. after focal*** |
Occ. |
CSME |
|
|
2 to 3 mos |
Yes |
Yes |
Obtain retinal consult in 2 to 4 wks |
Occ. after focal*** |
Yes |
High-risk PDR |
|
|
|
|
|
|
|
|
No macular edema |
|
|
2 to 3 mos |
Yes |
No |
Obtain retinal consult in 24 to 48 hrs |
Yes |
No |
Macular edema |
|
|
1 to 2 mos |
Yes |
Yes |
Obtain retinal consult in 24 to 48 hrs |
Yes |
Usually |
CSME |
|
|
1 to 2 mos |
Yes |
Yes |
Obtain retinal consult in 24 to 48 hrs |
Yes |
Yes |
Abbreviations: CSME, clinically significant macular edema; HRC, high risk category; NPDR, nonproliferative diabetic retinopathy; PDR, proliferative diabetic retinopathy; Occ., occasionally
*Patient education and written communication with patient's primary care physician are integral to management of DM.
** Consider scatter laser treatment (PRP), especially if every severe NPDR (see levels of DR), significant medical complication, or type 2 DM
*** Consider scatter laser treatment (PRP), especially if moderate PDR (see levels of DR), significant medical complication, or type 2 DM
Table copyright L.M. Aiello, M.D. Used with permission.