Case Study Branch Retinal Vein Occlusion

Lt Col P Lynne Walters

MFOM MRCGP DAv Med RAMC

Scope

Clinical history

Royal College of Ophthalmology guidance

UK/US Aviation policy

Outcome

Clinical History

Athletic 51 year old male Army helicopter pilot

Holds JAR Class 2 medical

September 2016 Normal opticians assessment

March 2017 Reduction of vision in left eye, not reported to medical personnel

29 April Approx 1 month later routine eye test at optician

engorged veins and nerve head of left eye with multiple haemorrhages superiorly and temporally.

R

L

Optometry reports

Date 29 May 15 5 Sep 16 5 May 17 12 Jun 17

Uncorrected VA Right

6/5 6/7.5 6/12

Corrected VA Right

6/5 6/6 6/5 6/4

Sph prescription +1.00 +1.50 +2.00

Cyl prescription -0.50 Axis 95

-0.75 Axis 95

-0.50 Axis 95

Near vision add +0.75 +1.50

Uncorrected VA Left

6/5 6/6-2 6/15

Corrected VA Left 6/5 6/6 6/5 6/4

Sph prescription +1.25 +2.00 +2.50

Cyl prescription -0.75 Axis 85

-0.75 Axis 85

-0.50

Near vision add +0.75 +1.50

Ophthalmology reports

Ophthalmology report

Best corrected VA 6/6 bilaterally

IOP 11mmHg right, 9mmHg left

C/D ratio 0.6 right, 0.5 left

Follow up 12 June

Best corrected VA bilaterally was 6/4

IOP 9mmHg bilaterally

C/D ratio 0.3 bilaterally

Few optic disc collaterals on left

Retinal vein occlusion

Location

Branch (BRVO)

Hemiretinal (HRVO)

Central (CRVO)

Degree of remaining perfusion

Ischaemic

Non-ischaemic

Sudden painless loss of vision

Differential diagnosis

Diabetic retinopathy

Radiation retinopathy

Severe hypertensive retinopathy

Papilloedema

Ocular ischaemic syndrome

RCOphth Guidelines July 2015

Central retinal vein occlusion (CRVO)

VA and macular oedema can improve but VA generally decreases with time.

Non ischaemic CRVO can resolve completely without complications

Follow up for 2 years

– development of disc collaterals and resolution of macular oedema allow discharge from follow up

30% may convert to ischaemic CRVO over 3 years

RCOphth Guidelines July 2015

Branch retinal vein occlusion

50-60% have VA better than 6/12 after 1 year

18-41% improve spontaneously

Approximately 20% of cases with macular oedema experience significant deterioration of VA with time

Epidemiology

Second commonest vascular cause of reduced vision after diabetic retinopathy

Prevalence

Australia < 60 years 0.7%

USA 0.7-1.6% general population usually over age 50 yrs

Most patients unilateral

Macular oedema is leading cause of visual impairment

Aetiology

Atherosclerosis of central retinal artery compressing central retinal vein.

Rarely- thyroid eye disease

Orbital tumour

Retrobulbar haemorrhage

Associations

Hypertension

Diabetes

Hyperlipidaemia

Hyperhomocysteinaemia

Blood coagulation disorders

Systemic inflammatory disorders

Glaucoma

Shorter axial length

Retrobulbar external compression

British Committee for Standards in Haematology (BCSH) Clinical Guidelines for testing for heritable thrombophilia (2010)

Thrombophilia testing not appropriate for RVO

No consensus that treating RVO with anticoagulant is beneficial, Antiphospholipid antibody testing not indicated.

RVO, peripheral arterial disease, peripheral venous disease and stroke share underlying risk factors.

RCOphth recommendations

Based on the current evidence,

careful cardiovascular assessment and

treatment of cardiovascular risk factors by the patient’s physician advocated in young male patients with RVO.

Recommended Investigations

Medical history, examine for lymphadenopathy

BP/ Ambulatory BP

Serum glucose

FBC

ESR

Lipid profile

Complications

Macular Oedema and ischaemia

Neovascularisation of the retina

CAA Guidance

Presentation of RVO- Unfit flying

Assess visual function

Assess cardiovascular incapacitation risk

CAA Requirements

From Ophthalmologist

Visual acuity in each eye separately

Visual field results in each eye separately

Binocular Esterman test

Evidence that IOPs are stable

CAA Requirements

Cardiovascular risk

Stable BP ( 24 hr ambulatory monitoring)

Assessment and management of cardiovascular risk factors

Exercise ECG- symptom limited by Bruce Protocol

Thrombophilia screen

CAA Disposition

Class 1

satisfactory ophthalmic and cardiological results fit OML

Abnormal findings require further investigation/assessment

Class 2

Satisfactory ophthalmic and cardiological assessments –unrestricted

Visual field defect or cardiovascular risks -OSL

FAA

All information to be submitted to FAA for decision

UK Military AP 1269A

No formal reference to RVO

All retinopathy to be grounded and assessed by the DCA Ophthalmology.

US Army AR 40-501

Granting of waiver depends on resultant VA and absence of other pathology.

Ophthalmology/optometry evaluation

VA must meet aeromedical standards

No neovascular glaucoma

Exclusion of other pathology e.g. hypertension, diabetes, blood dyscrasia, multiple myeloma and dysgammaglobulinaemia

Rule out valvular and carotid disease

USAF Waiver guide June 2013

Aeromedical concern

Final VA

Management of predisposing medical conditions

Risk of recurrence

Risk of neovascular glaucoma in ischaemic RVO (approaches 40% over one year)

Chronic macular oedema not waiverable

Literature suggests decreased retinal oxygen saturation up to 3 months after event

USAF Waiver guide

Waiver considerations

VA, permanent visual field defects

Recurrence

BRVO -10% risk of BRVO in fellow eye within 3 years ; CRVO 1% risk per year of fellow eye involvement

Complications

Neovascular glaucoma or macular oedema

Management of predisposing medical conditions

BP, heart disease, haematologic disease, collagen vascular disease

FBC, + differential, Glucose, HbA1C, PT/PTT, ESR, CRP, Lipids, ANA, Treponemal Ab, Homocysteine

USAF Waiver guide

US Navy guidance Aug 16

Consider for waiver after vision returns to class standards and no further treatment

Ophthalmology inc. retinal photos, macular OCT, Fluorescein angiography

Exclude Hypertension, DM, Blood dyscrasia, multiple myeloma, dysgammaglobulinaemia

Annual Ophthalmology review

Back to the case

Visual fields

Results

December 2015

Total cholesterol 5.6, Cholesterol:HDL 3.8

BP 123/68

Q-Risk 10 year risk of 3.7% (relative risk of 1)

May 2017

Total cholesterol 5.3. Cholesterol:HDL 3.8

Q-risk 3.8% (relative risk 0.8)

BP 110/65

TFT, U&E, LFT, Coag screen normal

CRP 1, ESR 6.

‘Hypercholesterolaemia’ treated with statin

Cardiology

Positive ETT- ST depression in lateral leads at Bruce stage 3

Dilated RV on echocardiography

CT angiogram- no coronary calcium, no evidence of coronary artery disease

Cardiac MRI- mild biventricular dilatation with normal ejection fraction, deemed acceptable by cardiologist

Disposition

Returned to full flying role but continues to fly with co-pilot.

References

https://www.rcophth.ac.uk/wp-content/uploads/2015/07/Retinal-Vein-Occlusion-RVO-Guidelines-July-2015.pdf

AP1269A

USAF waiver guide June 2013 Capt Marion Powell, Maj Tighe Richardson, Dr Dan Van Syoc

US Army AR40-501

Army Aviation Centre