With advancements in diagnostic technologies over the years, optometrists are now better equipped to assess, diagnose, manage, or refer patients who have posterior segment disorders. Certain conditions fall outside the provider’s scope or expertise, necessitating referral to a specialist or subspecialist. The decision to monitor, manage, or refer patients depends on factors, such as standard of care, the American Academy of Ophthalmology’s (AAO) Preferred Practice Patterns, evidence-based care, and the practitioner’s knowledge, skills, and comfort level. What’s more, urgency for referral varies. For instance, rhegmatogenous retinal detachment requires urgent referral due to the risk of vision loss without timely intervention, while diabetic macular edema (DME) may not require urgent referral. Establishing strong relationships and clear communication among the optometrist and other health care providers is essential for achieving optimal patient outcomes involving referrals to a retina specialist. The following is a discussion of some of the more common conditions that optometrists might refer to a retina specialist.

Diabetic retinopathy (DR)
DR is the leading cause of visual impairment in the working-age population and a commonly encountered disease by the OD. Primary eye care providers are often faced with the decision to refer patients who have DR to a retina clinic. The urgency of the referral timing depends on many factors, including the presence of DME and the disease severity. The other factor is the optometrist’s comfort with their assessment of the disease, as well as their access to appropriate diagnostic tools.

Currently, treatment in DR is primarily aimed at addressing DME and proliferative DR (PDR) or prevention of PDR by treating moderately severe or severe stages of nonproliferative DR (NPDR) that has center-involved macular edema (macular edema within the central subfield, 1 mm diameter centered on the fovea).

The most practical recommendation to refer patients who have DR is anytime there is a concern with potential permanent vision loss. Or, the OD can follow the American Optometric Association guidelines.¹

Patients who have severe PDR, vitreous hemorrhage, tractional retinal detachment and iris neovascularization should be referred to a see a retina specialist within 24 to 48 hours. Patients who have severe NPDR, PDR, or DME should be referred to see a retina specialist within two to four weeks. 

Age-related macular degeneration (AMD)
AMD is a leading cause of blindness in older patients in developed countries.² Until recently, treatment strategies were largely aimed at patients who had developed neovascular AMD (nAMD). With newly FDA-approved treatments to slow the progression of advanced atrophic AMD, or geographic atrophy (GA), identifying patients at risk of progression to advanced disease is a new challenge the optometrist faces.

Because of the threat of central vision loss, identifying patients who are at substantial risk of conversion or who have newly converted to nAMD is of paramount importance. Patients who have evidence of conversion to nAMD should be referred to be seen by a retina specialist ideally within days of conversion. The mainstay of treatment for nAMD is intravitreal anti-VEGF injections, which serve largely to stabilize visual acuity (VA) with the added potential of improving VA. 

With newly available therapies for GA, retina specialty clinics offering these treatments rely on referring practitioners to identify potential candidates, including those who have obvious GA, early GA, or who are at high risk for progression to GA. Patients who have detectible GA or who are at risk for GA, confirmed by examination and appropriate imaging, should be referred to a retina specialist for a second opinion and/or appropriate treatment. 

Peripheral retinal findings
Encountering peripheral retinal findings, such as lattice degeneration, retinal breaks, and detachments, can create a conundrum regarding the urgency of referral or necessity of treatment. Although the AAO’s Preferred Practice Patterns outline when to consider treatment for retinal breaks, establishing a relationship with a local retina specialist is helpful to understand their unique treatment patterns and preferences on the urgency of referral for specific types of breaks (asymptomatic vs. symptomatic, holes vs. tears, etc.)

Primary care ODs frequently encounter patients who have symptomatic posterior vitreous detachments (PVD). An estimated 8% to 22% of patients who have symptomatic PVD have a retinal break on initial examination, while 2% to 5% of patients without an initial break will go on to develop a break within six weeks.³ In these cases, prompt referral for treatment is recommended. About half of symptomatic tears will progress to a clinical rhegmatogenous retinal detachment (RRD) without treatment.³ Symptomatic retinal tears are frequently treated in office with laser or a cryotherapy barrier. Patients at increased risk of retinal tears include those who have lattice degeneration, -1.00 D to –3.00 D of myopia, a history of trauma, and cataract surgery.³ Vitreous hemorrhage or pigmented cells in the anterior vitreous are also associated with an increased likelihood of retinal breaks. Patients who have RRD sparing the macula should be urgently referred (same day) for either in-office treatment or prompt surgical intervention. Although patients who have macula-off RRD do not have to be seen same day, providers should aim for prompt referral to discuss procedural/surgical options.

Asymptomatic breaks, including atrophic retinal holes, holes within lattice, or operculated retinal holes are often discovered on routine examination, especially with the incorporation of widefield and ultra-widefield imaging in many practices. Asymptomatic retinal holes pose a very low risk of clinical retinal detachment, according to long-term studies; however, having a discussion with the patient regarding their risk is important.³ According to the AAO’s Preferred Practice Patterns, asymptomatic retinal breaks can be safely monitored with either bi-annual or annual dilated examination, as long as the patient is thoroughly counseled on symptoms of RD and the importance of monitoring their peripheral field monocularly. After discussion with their provider, patients may elect to seek treatment for asymptomatic breaks; these referrals are non-urgent. Asymptomatic retinal holes, or holes within lattice can often be treated in office with laser.

Vitreomacular interface disorders
Another common area for referral includes issues at the vitreoretinal interface, including epiretinal membranes (ERM) and vitreomacular traction (VMT). ERMs are a commonly occurring condition affecting an estimated 30 million adults in the United States.⁴ ERM can occur due to PVD or as a form of reactive wound healing in patients who have current or previous intraocular inflammatory conditions, retinal vascular disease, or retinal breaks and detachments.⁴ Although most ERMs remain stable over time, they may cause decreased vision, metamorphopsia, image size discrepancies, diplopia, and asthenopia. Symptomatic patients who complain of decreased visual function and trouble with activities of daily living should be considered candidates for surgical intervention in the form of vitrectomy with possible internal limiting membrane peeling. Asymptomatic patients can be managed with routine observation. 

Vitreomacular traction (VMT) is another condition that can result in similar visual symptoms. VMT results from adherence of the posterior vitreous cortex to the inner surface of the retina and is estimated to affect 0.4% to 2% of adults older than age 63 in the United States.⁴ Depending on its severity, VMT can cause varying levels of disruption to foveal architecture, and result in subretinal fluid or potentially progress to a full-thickness macular hole. An estimated 30% to 40% of eyes will have spontaneous release of VMT within one to two years;⁴ however, symptomatic patients can be counseled on the option of surgical intervention with vitrectomy. About 80% of patients who undergo vitrectomy for ERM and VMT will experience at least two lines of visual improvement.⁴

Basis for referral recommendations
The referral recommendations discussed here are based largely on the AAO’s published Preferred Practice Patterns. If retinal findings are outside a providers’ comfort zone, or a second opinion is desired, referral to a retina specialist can provide reassurance to both patients and providers. OM

References:

1. American Optometric Association. EVIDENCE-BASED CLINICAL PRACTICE GUIDELINE. Eye Care of the Patient with Diabetes Mellitus Second Edition. https://bit.ly/AOAClinicalPracticeGuidelineRetina. (Accessed August 28, 2024).

2. Flaxel CJ, Adelman RA, Bailey ST, et al. Age-Related Macular Degeneration Preferred Practice Pattern® Ophthalmology. 2020;127(9):1279. doi: 10.1016/j.ophtha.2020.06.048]. [published correction appears in Ophthalmology. 2020;127(1):P1-P65. doi:10.1016/j.ophtha.2019.09.024]

3. Flaxel CJ, Adelman RA, Bailey ST, et al. Posterior Vitreous Detachment, Retinall Breaks, and Lattice Degeneration Preferred Practice Pattern. Ophthalmology. 2020;127(9):1279. doi: 10.1016/j.ophtha.2020.06.049]. [published correction appears in Ophthalmology. 2020;127(1):P146-P181. doi:10.1016/j.ophtha.2019.09.027]

4. Flaxel CJ, Adelman RA, Bailey ST, et al. Idiopathic Epiretinall Membrane and Vitreomacular Traction Preferred Practice Pattern® [published correction appears in Ophthalmology. 2020;127(9):1280. doi: 10.1016/j.ophtha.2020.06.045]. Ophthalmology. 2020;127(2):P145-P183. doi:10.1016/j.ophtha.2019.09.022

MOHAMMAD RAFIEETARY, OD, FAAO, FORS, is a consultative optometric physician at the Charles Retina Institute, in Germantown, Tenn. He is on the advisory board of a number of professional organizations, and lectures and writes on posterior segment disease. Email him at mrafieetary@charlesretina.com.

Rachel Steele, OD, FAAO, ABO, is an optometry fellow at the Charles Retina Institute in Germantown, Tenn. and a consulting faculty member at the Southern College of Optometry. She completed a residency in ocular disease at the Memphis VA Medical Center, and is a diplomate of the American Board of Optometry.