Questions for FRCS Glasgow March,03
The following questions are contributed by past candidates of FRCS (Glasgow). Answer plans are given
below for reference only. Refer to essays for MRCOphth for advice regarding answering essay questions.
If you like to contribute, please e-mail me.
|A 40 year old male presents with a history of a foreign body hitting
the left eye whilst using a hammer and chisel that day, The visual acuity
is hand movement. There is a corneal laceration and a hyphaema is present.
How would you manage this patient?
The question is on a patient with ocular injury with or without retained foreign body. The answer should cover both immediate management and the after care.
A detailed history is essential to ascertain the type of foreign body (FB) which may enter the body and for medicolegal purposes. Time of last meal important if surgery needed as GA is preferable. Tetanus status.
Examination: VA, Siedel's positive?, presence of FB? Cataract? Retinal lesion? Dilate pupil to examine before cataract obscure view but hyphaema may make view difficult.
Further examination: X-ray and CT scan if retained FB suspected. MRI to be avoided if metallic FB can't be excluded.
Management depends on the findings:
a. if laceration not full thickness, Sidel's negative, no retained intraocular FB (IOFB) and noAdditional points:
If iron IOFB suspected in follow-up monitor ERG and repeat CT scan.A previously well 32 year old patient has increasing diplopia on upgaze. She has also noticed the right eye is more prominent. On examination, the visual acuity is normal, there is limitation of elevation of the right eye and 3mm of proptosis compared to the left eye. How would you proceed?
Although the most likely diagnosis is thyroid eye disease (TED). The answer should cover the history, differential diagnosis, investigation and management.
History of the symptoms, any pain, duration, associated medical problems (especially thyroid problem, any radioactive iodine treatment), smoking? (smoker has worse TED), previous cancer, previous head trauma?
Differential diagnosis: VEIN: Vascular problem, Endocrine problem, Inflammation and Infection and Neoplasm.
Ocular examination: Red eye, conjunctival arterialization? VA, lid retraction, amount of proptosis, type of proptosis (does it vary with Valsalva manoeuvre?, reducible with pressure?), corneal changes, IOP in primary and upgaze, colour vision, afferent pupillary defect, optic disc appearance, visual field. Orthoptist assessment for baseline and prescription of prism as necessary.
Physical examination: thyroid status, signs of Grave's disease (thyroid acropachy, pretibial myoxedema), lymphadenopathy? etc.
Investigation (depends on the findings): Blood test for thyroid function test and antibodies. CT or MRI if diagnosis not certain, Chest X-ray for any secondary. If scan suggests space occupying lesion biopsy needed to confirm diagnosis.
Management depends on the cause:
The answer should include ocular examination including the intraocular pressure check, risk of neovascularization. A brief discussion of the CVOS study may be useful. Physical examination to exclude cardiovascular disease such as hypertension. Blood tests to exclude diabetes mellitus, blood dyscrasia, auto-immune disorders and clotting tendency.
Investigation: Look for factors that may be treatable and prevent further occurrence in the same or fellow eye. Investigation should begin with the history for any systemic illness such as hypertension, tendency of clotting, skin or joint problem, headache and jaw claudication, then examination including:
In the eyes: examine the eyes for ocular hypertension and signs of inflammation and hyperviscosity syndrome.
Systemic examination: this include systemic hypertension and diabetes mellitus (check BP and fasting blood glucose), blood dyscrasias such as polycythaemia, increased plasma proteins and leukaemia (blood tests for full blood count and serum proteins) and predisposition to clotting (checked protein S and C level). ESR and C reactive protein for any systemic inflammation. Disorders such as sarcoidosis, SLE and Behcet's disease etc. (CXR, autoantibodies, ACE etc but the investigations should only be carried out based on the history and not blindly as the yield is low in asymptomatic patients). Temporal artery biopsy if history suggestive of giant cell arteritis.
Important to differentiate ischaemic from non-ischaemic CRVO. Close follow up important as about 1/3 of non-ischaemic CRVO can evolve into ischaemic CRVO.
Distinguishing between the two types of CRVO is clinically important. Eyes with ischaemic CRVO have a poor natural history: 67% will develop ocular neovascularization and 37% will develop neovascular glaucoma.
Pan-photocoagulation should be performed in ischaemic eye or eye with neovascularization (although the CVOS study show that PRP does not prevent iris or angle neovascularization.). Macular oedema is an important of decreased vision in both ischaemic and non-ischaemic CRVO but laser does not improve the vision.
The overall visual prognosis in eyes with CRVO is directly related to baseline visual acuity. After 3 years of follow-up, 65% of eyes with initial visual acuity of 20/40 or better retain their vision, whereas 79% of eyes with initial visual acuity less than 20/200 fail to gain visual improvement. Patients with CRVO also have a 1% annual risk for developing a vascular occlusion in their fellow eye.