ZEISS CIRRUS OCT

Collaborative Care In The Management of AMD and Geographic Atrophy

27 July 2023 · 5 min read

Collaborative Care In The Management of AMD and Geographic Atrophy

As with many chronic conditions, the incidence of age-related macular degeneration (AMD) is set to increase due to an aging population. It is projected that there will be 288 million AMD patients by 2040.1 Eyecare providers and healthcare institutions will have to brace for the impact of these AMD patients as we strive to provide high quality care in an ever-evolving treatment landscape. Optometrists and ophthalmologists will work together, using a common language and common imaging data to achieve our common goal of providing vision saving care. The ZEISS CIRRUS OCT with its Advanced RPE Analysis and AngioPlex® can provide the foundation on which optometrists and ophthalmologists can detect and monitor all forms of AMD.

  

AMD Classification and a Common Language

As summarized in table 1, there are two AMD classifications systems that have been commonly used in clinical care. The classic AREDS system and the newer Beckman Committee criteria are similar, but not interchangeable classification systems, that help eyecare providers properly stage AMD patients. It is important for the optometrist and ophthalmologist to use the same grading system to ensure accurate and proper collaborative care.

AMD Stage

Beckman Committee Criteria*

AREDS Criteria

No apparent aging changes

No drusen and no pigment abnormalities

-

Normal aging changes

-

-

No AMD

Small drusen only

No or few small drusen

Early AMD

Medium drusen only

Multiple small drusen, few medium drusen, and/or mild RPE abnormalities

Intermediate AMD

Large drusen and/or pigment abnormalities

Numerous medium drusen, at least 1 large druse, and/or non-center involving geographic atrophy

Late/Advanced AMD

Neovascular AMD and/or geographic atrophy

Center involving geographic atrophy, MNV or current/past signs of MNV

*All findings must be within 2 disc diameters of the fovea
Drusen: includes any drusen type and subretinal drusenoid deposits; Pigment abnormalities: any hyperpigmentation or hypopigmentation associated with medium or large drusen; RE: retinal pigment epithelium; MNV: macular neovascularization

The Advanced RPE Analysis, available on the ZEISS CIRRUS OCT, was specifically created to help clinicians manage non-neovascular AMD and can be used in early, intermediate, and late AMD. The RPE Elevation Map can measure drusen burden while the Sub-RPE Slab can detect and quantify areas of geographic atrophy (GA). As patients progress from early to intermediate and late stages of AMD, the Advanced RPE Analysis can be used to objectively quantify progression of drusen and GA. Proper AMD classification and objective OCT-based detection of AMD can help facilitate the comanagement relationship between optometry and ophthalmology, allowing each provider to work to the fullest extent of their practice scope.
With the advent of GA treatment, AMD comanagement will need to expand extensively to ensure that GA patients are identified early, referred to a retinal specialist, and that treatment is initiated when appropriate. The Classification of Atrophy Meeting anticipated the importance of accurate GA staging and created new definitions for GA. Summarized in Table 2, “GA” is considered to be a clinical term, whereas “complete RPE and outer retinal atrophy (cRORA)” will be used as the preferred OCT-based definition of GA. As with AMD grading, it will be important for optometrists and ophthalmologists to use the latest nomenclature to create proper referral patterns and management protocols.

AMD Finding

Description

Geographic Atrophy

Clinical term used to denote areas of retinal and RE atrophy without the presence of present/past CNV

iRORA

Vertically aligned photoreceptor/outer retinal degeneration, RE attenuation or disruption, and increased signal transmission into the choroid
Must not qualify as cRORA

cRORA

Vertically aligned zone of hypertransmission of ≥250 um, zone of attenuation or disruption of RPE band of ≥250Mm, and evidence of overlying photoreceptor degeneration whose features include ONL thinning, ELM loss, and EZ or IZ loss
Must exclude scrolled RPE or other signs of RPE tear

RPE: retinal pigment epithelium; iRORA: incomplete RPE and retinal atrophy; cRORA: complete RPE and retinal atrophy; ONL: outer nuclear layer; ELM: external limiting membrane; EZ: ellipsoid zone; IZ: interdigitation zone; CV: choroidal neovascularization

The Patient’s AMD Journey

For many years the AMD journey was quite binary. Optometrists and general ophthalmologists would monitor AMD patients and refer to a retinal specialist when antiVEGF treatment was necessary. In the era of GA treatment, the AMD patient’s journey will now be more variable and the role of accurate diagnostics will become even more important. Many questions still remain as to when and for whom GA treatment will be necessary. As referral patterns are shaped on a local and national level, optometrists, general ophthalmologists, and retinal specialists will likely be inundated with AMD patients. The collaborative eyecare model between optometrists, ophthalmologists, and retinal specialists will become even more important to ensure that the necessary patients attain proper treatment.

This collaborative eyecare relationship will likely require more shared care than previous AMD comanagement relationships. The use of OCT-based definitions set forth by the Classification of Atrophy Meeting and OCT-based analyses, such as the Advanced RPE Analysis, will ensure seamless transitions back and forth between the optometrist and the retinal specialist. Initially, GA patients will need to be assessed through ophthalmoscopy and then confirmed with OCT. It will be important to use standardized OCT criteria of cRORA and iRORA to determine the necessity for referral to a retinal specialist. The Sub-RPE Slab can be used to detect predetermined criteria for GA referral, as agreed upon by the optometrist or ophthalmologist, and retinal specialist. These predetermined criteria may include GA distance from the fovea, overall GA area, or amount of GA progression; all of which can be objectively and automatically calculated using the Advanced RPE Analysis.

When a treatable GA candidate is identified, the patient can be referred to the retinal specialist to consider treatment. If treatment is initiated, the Advanced RPE Analysis can be used to monitor for treatment effect using the progression analysis report. Because patients undergoing GA treatment with complement inhibition are at a higher risk of developing neovascular AMD, careful monitoring and screening for neovascular AMD will be required. OCT angiography (OCTA) systems such as the ZEISS CIRRUS AngioPlex® will become more important because OCTA can noninvasively screen for neovascular AMD. Using OCTA, doctors will ideally be able to detect neovascular AMD in its nonexudative form, before significant vision loss occurs.

Practice Management and the Collaborative Care Model

The cataract surgery and refractive surgery space has shown how collaborative care between optometry and ophthalmology can be a win-win-win situation; with optometrists, ophthalmologists, and patients all gaining in this relationship. Optometrists can practice full scope, caring for patients with non-injectable AMD. Meanwhile, retinal specialists can free up their schedules by discharging non-injectable AMD patients to the referring OD. This retinal co-management paradigm would allow retinal specialists to provide true tertiary care with retinal treatments. Meanwhile, the patient gains seamless personalized high quality AMD care from two collaborating doctors. ZEISS CIRRUS OCT helps facilitate this ideal collaborative relationship by providing objective and reproducible dry AMD imaging with the Advanced RPE Analysis and neovascularization detection with AngioPlex®. This high-tech approach can help ensure that proper referrals are generated, reducing the need for patients to bounce between practices for non-treatable AMD care. Collaboration will be especially useful in rural areas, where patients may have to travel hours to see a retinal specialist.

The swelling wave of AMD patients will be arriving whether or not the healthcare system is ready. As optometrists and ophthalmologists, it is our duty to make sure that we provide the necessary care to these patients. The only way to do this will be to incorporate the latest evidence-based medicine, technologies, and collaborative care models to provide high quality and efficient care. Hopefully we will be able accomplish what our patients and the healthcare system ask of us, ultimately saving millions from vision loss.


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    Wong, Wan Ling, et al. "Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: a systematic review and meta-analysis." The Lancet Global Health 2.2 (2014): e106-e116