Shared Care of the Retina Patient

Optimizing patients’ outcomes through collaborative care.

By Julie Rodman, OD, MS, FAAO

Patients with retinal disease can benefit from an interdisciplinary collaborative care approach between optometry and ophthalmology. In order for this symbiotic relationship to be effective, the optometrist must demonstrate proficiency and expertise in the diagnosis and management of retinal disease. This includes having a comprehensive understanding of completed and ongoing clinical trials that will help dictate the standard of care for various conditions.

Early and efficient access to care is crucial for overall patient outcomes; therefore, creating professional relationships with retina specialists is advantageous for both optometrists and ophthalmologists. Retina specialists benefit because they can see patients sooner and thus provide intervention earlier, when appropriate. This arrangement also allows the optometrist to be fully aware of the patient’s ocular history, including treatments and surgeries that they have undergone and medications that they are taking. Working directly with retina specialists also allows more efficient access to the appropriate provider, thus potentially saving the patient time and money.

Although there may be differences in management approaches among optometrists due to variations in their comfort levels, certain landmark trials have provided guidelines that dictate when referrals should be instituted. There is an abundance of opportunities for shared care, but among the most common retinal conditions that necessitate collaborative management are macular edema, diabetic retinopathy, and neovascular age-related macular degeneration (AMD).

DIABETIC RETINOPATHY

Management guidelines and treatment criteria for diabetic retinopathy have been well established by the DRS (Diabetic Retinopathy Study), the ETDRS (Early Treatment Diabetic Retinopathy Study), and the DRVS (Diabetic Retinopathy Vitrectomy Study Research Groups).1-4 Studies by these groups have resulted in guidelines that help determine at what point in the course of diabetic retinopathy surgical intervention should be instituted.

Figure 1. Fundus photograph of an eye with CSME; circinate exudate within 500 μm of the center of the macula with adjacent thickening.

Optometrists should refer any diabetic patient with evidence of sight-threatening retinal disease to a retina specialist. This includes clinically significant macular edema, or CSME, and any other retinopathy that involves the center of the macula. CSME is defined as retinal thickening at or within 500 µm of the center of the fovea; hard exudates at or within 500 µm of the center of the fovea with adjacent retinal thickening; or at least 1 disc diameter of retinal thickening, any part of which is within 1 disc diameter of the center of the fovea (Figure 1).1

The use of diagnostic equipment such as optical coherence tomography (OCT) can assist in classifying diabetic macular edema (DME) by evaluating retinal thickness, volume, morphology, diffusion, and epiretinal traction. Careful assessment of these factors can help to determine the urgency of referral due to the significant association between visual morbidity and foveal involvement (Figure 2).5

Treatment options for DME comprise several therapies that can be used in conjunction or alone, including injection of a vascular endothelial growth factor (VEGF) inhibitor, focal/grid macular laser surgery, and corticosteroids. Anti-VEGF drugs include ranibizumab (Lucentis; Genentech), aflibercept (Eylea; Regeneron), bevacizumab (Avastin; Genentech), and pegaptanib sodium (Macugen; Bausch + Lomb).6 Steroid options including intravitreal triamcinolone acetonide injection, the dexamethasone intravitreal implant 0.7 mg (Ozurdex; Allergan), and the fluocinolone acetonide intravitreal implant 0.19 mg (Iluvien; Alimera Sciences) have been shown to effectively reduce macular edema.7

Figure 2. OCT of the same eye as in Figure 1, showing DME.

Proliferative diabetic retinopathy in the form of neovascularization of the disc, iris, or elsewhere, as well as evidence of vitreous or preretinal hemorrhage, should be referred to a retina specialist, as panretinal photocoagulation (PRP) or vitrectomy may be indicated.1-4

AMD

AMD is another pathology that can be collaboratively managed by optometry and ophthalmology. Optometrists are well equipped to manage the nonexudative or dry form of AMD. Clinical signs of dry AMD include macular drusen, pigment clumping in the outer retina, and atrophy of the retinal pigment epithelium.

OCT is a fundamental tool in the evaluation of AMD patients. It aids in the detection of exudative or wet AMD, including the presence of choroidal neovascularization; it can assist in identifying the location of leakage and highlight possible involvement of adjacent areas (Figures 3 and 4).

Patients who exhibit evidence of exudative AMD should be promptly referred to a retina specialist. Clinical findings may include subretinal fluid or blood, pigment epithelial detachment, serous detachment, intraretinal fluid, retinal exudation, and decreased vision of unknown etiology. With the availability of anti-VEGF agents, timely and appropriate referrals may be able to halt disease progression and thus prevent vision loss or even improve vision in some cases. Identification of any evidence of wet AMD necessitates a retina referral for fluorescein angiography or indocyanine green angiography to assess evidence of subretinal or choroidal neovascularization.

Figure 3. Fundus photograph of an eye with exudative AMD.

Figure 4. OCT shows choroidal neovascular membrane associated with exudative AMD.

Macular photocoagulation has historically been the treatment for choroidal neovascular lesions. However, due to high recurrence rates, risk of vision loss, and failure to lead to visual improvement, photocoagulation has limited utility in the treatment of AMD.8 The advent of anti-VEGF agents has revolutionized treatment of AMD in the past decade. Photodynamic therapy with Visudyne (verteporfin for injection, Bausch + Lomb) is another option.9-11

RETINAL VASCULAR DISEASE

Due to the high incidence and visual morbidity associated with retinal vascular occlusive disease, collaborative management of these cases with a retina specialist is highly recommended.

Central retinal vein occlusion (CRVO) is characterized by optic disc swelling, increased venous dilatation and tortuosity, widespread hemorrhages, cotton wool spots, retinal edema, and capillary nonperfusion. Management of CRVO is aimed at identifying potentially causal and treatable systemic or local risk factors. In patients with CRVO, referral to a retina specialist is mandated in the event of suspected neovascularization (neovascularization of the disc, iris, or elsewhere, or neovascular glaucoma) or recalcitrant macular edema.12,13

The specialist will use fluorescein angiography to assess the extent of retinal capillary nonperfusion in CRVO and to help guide treatment. Intravitreal triamcinolone injection, dexamethasone intravitreal implant, and intravitreal anti-VEGF drugs (ranibizumab, aflibercept, or bevacizumab) are all options for treatment of macular edema.

Figure 5. Fundus photograph of an eye with branch retinal vein occlusion with macular edema.

Figure 6. OCT of chronic macular edema secondary to branch retinal vein occlusion.

Other complications such as retinal neovascularization can be treated effectively with scatter PRP. The CVOS (Central Vein Occlusion Study) reported the efficacy of PRP in preventing neovascular glaucoma.14

Management of branch retinal vein occlusion (BRVO) should include referral to a retina specialist if complications such as neovascularization or chronic macular edema develop (Figures 5 and 6). Treatment modalities for BRVO include laser photocoagulation, injection of steroid or anti-VEGF agent for macular edema, and PRP or anti-VEGF agent for neovascularization. As in CRVO, collaboration with the patient’s primary care physician for directed workup and management of the condition underlying the BRVO is crucial. Timely referral to the retina specialist can minimize the visual morbidity associated with macular edema.15-21

CONCLUSION

Myriad retinal conditions are amenable to collaborative management between optometry and ophthalmology. Ophthalmologists are becoming more familiar with the vast array of knowledge and expertise that optometrists possess, and this is making collaborative retina care easier and more beneficial for both parties. It is the responsibility of optometrists to stay on the forefront of our field and remain current on the standards of care regarding retinal disease. Strong interdisciplinary relationships will most importantly benefit our patients and their visual outcomes.

1. Early Treatment Diabetic Retinopathy Research Group. Photocoagulation for diabetic macular edema: Early Treatment Diabetic Retinopathy Study Report Number 4. Int Ophthalmol Clin. 1987;27:265-272.

2. Early Treatment Diabetic Retinopathy Research Group. Early photocoagulation for diabetic retinopathy: Early Treatment Diabetic Retinopathy Study Report Number 9. Ophthalmology. 1991;98:766-785.

3. Diabetic Retinopathy Study Research Group. Photocoagulation treatment of proliferative diabetic retinopathy: The second report of diabetic retinopathy findings. Ophthalmology. 1978;85:82-106.

4. Diabetic Retinopathy Vitrectomy Study Research Group. Early vitrectomy or severe proliferative diabetic retinopathy in eyes with useful vision. Clinical application of results of a randomized trial. Diabetic Retinopathy Vitrectomy Study Report 4. Ophthalmology. 1988;95:1321-1334.

5. Sikorski BL, Malukiewicz G, Stafiej J, et al. The diagnostic function of OCT in diabetic maculopathy. Mediators of Inflammation. 2013;2013:1-12.

6. Boyer DS, Hopkins JJ, Sorof J, et al. Anti-vascular endothelial growth factor therapy for diabetic macular edema. Ther Adv Endocrinol Metab. 2013;4:151-169.

7.Bonini Filho MA, Jorge R, Barbosa J, Costa RA. Intravitreal injection versus sub-Tenon’s infusion of triamcinolone acetonide for refractory diabetic macular edema: a randomized clinical trial. Invest Ophthalmol Vis Sci. 2005;46:3845-3849.

8. Macular Photocoagulation Study Group. Argon laser photocoagulation for senile macular degeneration. Results of a randomized clinical trial. Arch Ophthalmol. 1982;100:912-918.

9. Barthelmes D, Walton R, Campain AE, et al. Outcomes of persistently active neovascular age-related macular degeneration treated with VEGF inhibitors: observational study data. Br J Ophthalmol. 2014;99:359-364.

10. Pinheiro-Costa J, Freitas-da-Costa P, Falcão MS, et al. Switch from intravitreal ranibizumab to bevacizumab for the treatment of neovascular age-related macular degeneration: clinical comparison. Ophthalmologica. 2014;232:149-155.

11. Solomon SD, Lindsley K, Vedula SS, et al. Anti-vascular endothelial growth factor for neovascular age-related macular degeneration. Cochrane Database Syst Rev. 2014;(8):CD005139.

12. Central Vein Occlusion Study Group. Natural history and clinical management of central retinal vein occlusion. Arch Ophthalmol. 1997;115:486-491. published erratum in Arch Ophthalmol. 1997;115:1275.

13. Yeh S, Kim SJ, Ho AC, Schoenberger SD, et al. Therapies for macular edema associated with central retinal vein occlusion: a report by the American Academy of Ophthalmology. Ophthalmology. 2015;122:769-778.

14. The Central Vein Occlusion Study Group. Natural history and clinical management of central vein occlusion. Arch Ophthalmol. 1997;115:486-491.

15. Varma R, Bressler NM, Suñer I, et al. Improved vision-related function after ranibizumab for macular edema after retinal vein occlusion: results from the BRAVO and CRUISE trials. Ophthalmology. 2012;119:2108-2118.

16. Larsen M, Waldstein SM, Boscia F, et al. Individualized ranibizumab regimen driven by stabilization criteria for central retinal vein occlusion: twelve-month results of the CRYSTAL study. Ophthalmology. 2016;123:1101-1111.

17. Boyer D, Heier J, Brown DM, et al. Vascular endothelial growth factor Trap-Eye for macular edema secondary to central retinal vein occlusion: six-month results of the phase 3 COPERNICUS study. Ophthalmology. 2012;119:1024-1032.

18. Ogura Y, Roider J, Korobelnik JF, et al. Intravitreal aflibercept for macular edema secondary to central retinal vein occlusion: 18-month results of the phase 3 GALILEO study. Am J Ophthalmol. 2014;158:1032-1038.

19. Panozzo G, Parolini B, Gusson E, Pignatto LS. Diabetic macular edema: an OCT-based classification. Semin Ophthalmol. 2004;19:13-20.

20. [no authors listed]. Argon laser photocoagulation for senile macular degeneration. Results of a randomized clinical trial. Arch Ophthalmology.1982;100:912-918.

21. [no authors listed]. A randomized clinical trial of early panretinal photocoagulation for ischemic central vein occlusion: the Central Retinal Vein Occlusion Study Group N Report. Ophthalmology. 1995;102:1434-1444.

Julie Rodman, OD, MS, FAAO
• Associate professor, Nova Southeastern University, Fort Lauderdale, Florida
• (954) 262-1779; rjulie@nova.edu
• Financial disclosure: consultant to Optovue