Central Retinal Artery Occlusion

Last updated on 6/12/20 | First published on 1/17/19 | Literature review current through Feb. 2021 [cite]

Authors: Jeff Mize RRT, CHT, CWCA, Tiffany Hamm BSN, RN, ACHRN, CWS, Steven Orr MD, FACEP/UHM, FAPWCA, Elaine Horibe Song MD, PhD, MBA, Topic editors: Eugene Worth MD, M.Ed., FABA, ABPM/UHM,

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INTRODUCTION

Treatment Protocol Guidelines

The following hyperbaric medicine treatment protocol is based upon the recommendations of the Hyperbaric Oxygen Committee of the Undersea and Hyperbaric Medical Society. Clinical protocols and/or practice guidelines are systematically developed statements that help physicians, other practitioners, case managers and clients make decisions about appropriate health care for specific clinical circumstances.

Protocols allow health providers to offer evidence-based, appropriate, standardized diagnostic treatment and care services to patients undergoing hyperbaric oxygen therapy (HBOT). Evidenced-based medicine offers clinicians a way to achieve improved quality, improved patient satisfaction, and reduced costs. This discussion will cover Central Retinal Artery Occlusion (CRAO) and HBOT. Utilization Review should be initiated when clinical decisions result in deviation from or modification of treatment protocols. This includes any course of treatment at or above the recognized threshold limits.

Medical Necessity

Medicare.gov defines “medically necessary” as “health-care services or supplies needed to prevent, diagnose, or treat an illness, injury, condition, disease, or its symptoms and that meet accepted standards of medicine.”

The following condition is NOT a covered indication per the National Coverage Determination (NCD) 20.29. [1] This medical condition shall not be treated adjunctively or primarily by HBOT for reimbursement by the Medicare program as data supporting its use has not been established as medically beneficial. Services deemed treatment for these primary conditions will be denied as Not Reasonable and Necessary. Some private third-party payers will cover HBOT for CRAO. We suggest you review the LCD for those particular payers.

TREATMENT PROTOCOL

 Sample Physician Order | $ ICD-10 Crosswalk |  Treatment Table |  Emergent / Urgent Indication

Background	Central retinal artery occlusion (CRAO) is an emergent rare eye disorder that typically produces sudden severe, painless, and irreversible vision loss in the affected eye. Patients at risk include those with giant cell arteritis, atherosclerosis and thromboembolic disease. Once the arterial supply to the retina is occluded, variable degrees of tissue loss may occur within 90 to 120 minutes. This may be irreversible without immediate diagnosis and intervention. Early HBOT appears to have a beneficial effect on visual outcome in patients with CRAO. [2]
Goals of HBOT	Increase oxygen levels in hypoxic/ischemic inner retinal layers to maintain tissue viability (via oxygen diffusion from the choroidal circulation) Prevent retinal edema Reduce/prevent ischemia-reperfusion injury if clot obstructing central retinal artery undergoes autolysis The artery generally recanalizes within 48 - 72 hours, so HBOT is short-term and based solely on return of vision to the affected eye.
Diagnosis	Sudden, painless visual loss, generally unilateral Findings upon fundoscopic exam with dilation: Pale yellow/ white-appearing retina due to ischemia or necrosis A cherry red spot in the macula (this is finding may not always be present) Other physical exam findings may include an afferent pupillary defect (Marcus Gunn pupil) and segmentation of blood in retinal arterioles (boxcarring)
Hyperbaric Criteria	Clinical findings suggestive of CRAO, with onset of symptoms within the first 24 hours. However, most patients wake after sleeping to unilateral blindness, and the sooner HBOT is initiated, the better chance to preserve retinal tissue. Best outcomes when HBOT is initiated within 8 hours from onset.
Evaluation	During workup, deliver 100% supplemental oxygen utilizing a non-rebreather mask Past medical history: Patients at risk include those with giant cell arteritis, atherosclerosis, vasospasm, and thromboembolic disease. The presence of "flashes or floaters" preceding vision loss, pain history of recent trauma, or age <40 suggest an alternate diagnosis (retinal detachment/vitreous hemorrhage) Physical examination: Visual acuity per ophthalmology should be documented as soon as possible. Intraocular pressure should be measured and treated if elevated but should not delay HBOT Labs to order or review: Do not delay HBOT to accomplish any of these. Complete Blood Count (CBC) - to screen for platelet disorders or infectious causes Erythrocyte Sedimentation Rate (ESR) C-reactive protein (CRP) Coagulation panel- (fibrinogen, prothrombin time (PT)/ partial thromboplastin time (PTT), antiphospholipid antibody) Lipid panel Electrocardiogram (ECG) Carotid ultrasound Echocardiography For suspected arteritic CRAO, treatment with intravenous corticosteroids should be initiated emergently
Treatment	Treatment should be titrated to patient response as follows: Start with hyperbaric oxygen therapy at 2.0 ATA oxygen for 90 minutes, reassess after 30 minutes: If vision improves significantly at 2.0 ATA, remain at this depth for the rest of the treatment. If vision fails to improve significantly at 2.0 ATA after 30 minutes, compress to 2.4 ATA. Two 5-10 minute air breaks are required for pressures exceeding 2.0 ATA If 2.4 ATA compression is needed, reassess after 30 min: If vision improves significantly at 2.4 ATA, conduct a U.S. Navy treatment Table 6. If vision does not improve significantly at 2.4 ATA, you may consider compressing to 2.8 ATA. If no improvement occurs after the first 20-minute breathing period, consider converting to a U.S. Navy Treatment Table 6. If U.S. Navy Treatment Table 6 is needed, reassess after 30 min: If vision improves significantly with the U.S. Navy Treatment Table 6, complete the treatment. Post-treatment, consider inpatient monitoring and supplemental oxygen. Recovery of vision during the initial treatment of CRAO with HBOT indicates some retinal viability. If there is no response to the initial U.S. Navy Treatment Table 6, options are to give 2 additional treatments at 2.8 ATA with two ten-minute air breaks twice daily, to discontinue HBOT, or continue with normobaric oxygen.
Follow-Up	Immediately after completion of HBOT, monitor patient and visual status at the chamber for 2 hours If vision remains normal and admission to hospital is not possible, patient may be discharged home with instructions to monitor vision every hour If vision loss recurs, continue HBOT twice daily until the angiogram normalizes or until visual improvement is present and does not change between treatments If patient is a non-responder, this should be evident in the first 2-3 treatments. Follow up by retina specialist
Treatment Threshold	6 – 12 treatments (Utilization/peer review recommended for patients treated for more than three days after clinical plateau and no further improvement.)
Coding	Refer to the ICD-10 Guideline for the appropriate ICD-10 code
Comments	If diabetes mellitus, blood glucose should be checked within an hour prior to treatment and immediately post-HBOT by unit personnel. This indication is not covered by Medicare but may be covered by commercial carriers. Medicare patients must sign an Advanced Beneficiary Notice (ABN) to receive HBO treatment.

Primary Sources: Whelan and Kindwall [3], Weaver[4]

DOCUMENTATION

History and Physical

Sample history for Central Retinal Artery Occlusion is shown below:

"Mr. Roberts is a 76 y/o man who awakened this morning with total blindness of the right eye. He went to bed at 10PM last night with good vision bilaterally. He states that he arose once in the middle of the night to urinate. He cannot remember his visual status at the time, but he was not concerned and turned on no lights. This morning at 7AM, he arose and noted no vision in the right eye.

He came to the emergency room for evaluation. The emergency room doctor confirmed that there was no vision in the right eye, and he also confirmed that the retina was pale. The ophthalmologist evaluated Mr. Roberts, performed an injection in the right eye and called us to evaluate the patient for Central Retinal Artery Occlusion.

We noted that the retina has been without blood flow for at least 9 hours from the middle of the night, and at most 12 hours from bedtime the night before. In this situation, time from onset of occlusion is vitally important. This patient is a good candidate for hyperbaric oxygen therapy in hopes to provide oxygen to the damaged retina for the next 36 - 48 hours while the retinal artery recanalyzes. This is an emergent indication for hyperbaric therapy. Failing to act will ensure total, irreversible blindness in the eye. We are happy to assist."

Physical Exam

Sudden, painless visual loss, generally unilateral
Findings upon fundoscopic exam with dilation:
- Pale yellow/ white-appearing retina due to ischemia or necrosis
- A cherry red spot in the macula (this is finding may not always be present) (Figure 1)
Other physical exam findings may include an afferent pupillary defect (Marcus Gunn pupil) and segmentation of blood in retinal arterioles (boxcarring)

Figure 1. Central retinal artery occlusion with cherry-red spot, retinal edema and narrowing of the vessels.

Impression

Central Retinal Artery Occlusion Refer to ICD-10 Crosswalk

Plan

There are several treatment options described in the medical literature. Hyperbaric oxygen can be delivered at 2.4 atmospheres absolute with 90 minutes of oxygen breathing during a 120 minute treatment. This will be repeated twice daily until maximum visual acuity is obtained. A second option for treatment involves treating at 2.4 atmospheres absolute for 30 minutes. If there is no improvement in visual acuity, the treatment pressure is increased to 2.8 atmospheres absolute, following a US Navy Treatment Table 6 protocol. Further treatments at 2.4 or 2.8 atmospheres absolute are administered on a twice daily regimen until visual acuity no longer improves.

Risk and Benefit of Hyperbaric Oxygen Therapy

Please refer to topic "Documentation HBO: Risks and Benefits"

Indication for Hyperbaric Oxygen Therapy (HBOT)

Central retinal artery occlusion (CRAO) is a rare eye disorder that typically produces severe and irreversible vision loss in the affected eye. There is some anatomic variation to the arterial blood supply to the retina. However, these patients usually present to the ophthalmologist with sudden visual loss, generally unilateral, and painless. Once the arterial supply to the retina is occluded, variable degrees of tissue loss occur within 90 to 120 minutes. This may be irreversible without intervention.

A number of different treatment regimens have been used with variable degrees of success. Frequently, there has been no improvement in visual acuity once blood supply to the retina has been lost. There have been a number of different pathophysiologic etiologies described with a common denominator of interrupted arterial supply to the retinal tissue. Here have been several studies showing that addition of HBOT as soon as possible has resulted in increased visual acuity by 2 to 3 lines on a Snellen eye chart. This may make the difference between light perception only to finger counting or television vision.

Hyperbaric Plan

Sample Order

 See sample physician order

CATEGORY A CONTINUING EDUCATION CREDIT

This topic has been reviewed and approved by the National Board of Diving and Hyperbaric Medical Technology (NBDHMT) for one (1) Category A Credit.

To claim the credit:

Read the topic
Answer the examination and course critique questions. See "Central Retinal Artery Occlusion - Examination and Course Critique Questions"
Receive the certificate by e-mail. A passing score of 70% is required (please allow up to 8 business days for processing)

For more information on Category A continuing education credits see blog post " Hyperbaric Certification and Continuing Education for Technicians & Nurses".

REVISION UPDATES

Date	Description
5/5/2019	Added section on Documentation
1/27/2020	Added section 'Category A Continuing Education Credit'

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NOTE: This is a controlled document. This document is not a substitute for proper training, experience, and exercising of professional judgment. While every effort has been made to ensure the accuracy of the contents, neither the authors nor the Wound Reference, Inc. give any guarantee as to the accuracy of the information contained in them nor accept any liability, with respect to loss, damage, injury or expense arising from any such errors or omissions in the contents of the work.

REFERENCES

Topic 610 Version 4.0

Central Retinal Artery Occlusion

Central Retinal Artery Occlusion

INTRODUCTION

Treatment Protocol Guidelines

Medical Necessity

TREATMENT PROTOCOL

DOCUMENTATION

Physical Exam

Impression

Plan

Risk and Benefit of Hyperbaric Oxygen Therapy

Indication for Hyperbaric Oxygen Therapy (HBOT)

Hyperbaric Plan

Sample Order

CATEGORY A CONTINUING EDUCATION CREDIT

REVISION UPDATES

REFERENCES

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