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Ophthalmology
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Important features in the History
- If you would like to have a go at adding some “top tips” to this page for this specialty (and have your name displayed proudly with bradfordvts), please email me – rameshmehay@googlemail.com
It is estimated that 2% of patients attending their GP have some forms of eye complaints.
History
- History and appropriate eye examination can usually unravel the underlying problems and help in deciding the need or urgency of ophthalmic referrals.
- History is an important part of the examination.
- Patients with sudden onset visual loss or painful red eye usually require ophthalmic opinions.
- Previous similar episodes should be noted as conditions such as herpes simplex keratitis and iritis can recur.
- History of industrial injury should be recorded as it may have medicolegal implication.
Important features in the Examination
Examination
- All patients with eye complaints should have distant visual acuity recorded using a Snellen chart. Glasses should be used if worn.
- In patients with severe blepharospasm from pain, topical anaesthesia should be instilled and the visual acuity rechecked.
- The examination techniques should be tailored according to the patients complaints.
Examination Tools
- Snellen chart
- Hand-held ophthalmoscope
- Torch with a blue filter
- Fluorescence drop or fluorescence impregnated paper
- Topical anaesthesia (e.g. amethocaine drops)
- Magnifier preferably X8
- Topical short acting mydriatic preferably tropicamide
Red Flags
In patient with red eye:
- Eyelids and the anterior segment examined with the magnifier in patients with red eyes noting:
- any lid swelling
- conjunctivitis
- ciliary injection (injection around the cornea which occurs in iritis and corneal problems)
- corneal ulcers or foreign body
- cloudy cornea which impaired the view of the iris (seen in acute glaucoma)
- Check the integrity of the corneal epithelium by instilling fluorescein.
- Any corneal defect will show up green when examined with a blue light.
- Eversion of the upper lid should be performed in patient with corneal staining suggestive of abrasion as there may be subtarsal foreign body.
- This is performed by instructing the patient to look down and evert the lid against a cotton bud.
In patients with blurred vision:
- Visual field examination by confrontation to check that the patient can see each quadrant.
- Pupillary reaction to light.
- Test that the pupils react to light directly and consensually, then perform the swinging light test.
- The swinging test is performed by shining light into one eye and then the other.
- In normal reaction the pupil should constrict each time the light is shone.
- If the pupil dilates, a relative afferent pupillary defect is present and this is indicative of a significant retinal problem or optic nerve dysfunction.
- Dilate the pupil with tropicamide and examine the fundus starting with the optic disc, the blood vessels, the macula and the periphery.
Click here for “How to use direct ophthalmoscope”
Guidelines for Ocular Referrals
The following is a quick guideline for ocular referrals, if you have any doubt about the patient’s diagnosis please contact the eye casualty during the opening hours or the ophthlamologist on-call when the casualty is closed.
Immediate Referral
Red eye (non-traumatic cases)
- Acute glaucoma
- Painful eye after cataract operation
Trauma:
- Chemical burn
- Corneal laceration
- Globe perforation
Sudden visual loss:
- Giant cell arteritis
- Retinal artery occlusion
- Any sudden visual loss of less than 6 hours and cause unknown
Third nerve palsy
(with pupil involvement i.e. dilated pupil)
Same day (within 24h)
Red eye:
- Iritis
- Corneal infection
Trauma:
- Blunt trauma
- Corneal abrasion
- Foreign body
Swollen lids:
- Herpes zoster with eye involvement
- Orbital cellulitis
Sudden visual loss:
- Vitreous haemorrhage
- Sudden visual loss of more than 6 hours
- Sudden onset floaters
- Retinal detachment
Same Week
- Persistent conjunctivitis
- Episcleritis
- Facial nerve palsy – unless there is severe corneal exposure then within 24 hours.
Does not need referral
- Sticky eye of less than 24 hours without pain
- Chalazion (refers to the minor operating list.)
Other Top Tips - How to use a direct Ophthamoscope
How to use a direct ophthalmoscope
The direct ophthalmoscope is a useful tool but often under utilized by non-ophthalmologists. The following steps will help the doctors to obtain a good fundal view provided the patient has clear media i.e. without corneal, lens or vitreous opacities.
- To examine the right eye, sit or stand at the patient’s right side.
- Select “0” on the lens disc of the ophthalmoscope and start with the small aperture.
- Hold the ophthalmoscope vertically in the right hand and placed it in front of your right eye with the light beam directed toward the patient .
- Place your right index finger on the edge of the lens dial so that you may change lenses easily if necessary.
- Dim room lights.
- Instruct the patient to look straight ahead at a distant object.
- Note: If the patient looks at the light or focus on near object, the pupil will constrict due to accommodation making examination difficult.
- Position the ophthalmoscope about 6 inches (15 cm) in front and slight to the right (250) of the patient and direct the light beam into the pupil.
- A red reflex should appear as you look through the pupil.
- Note: Absence of red reflex occurs in dense cataract or scarred cornea.
- While the patient is fixating on the specified object, keep the reflex in view and slowly toward the patient.
- The optic disc should come into view when you are about 11/2 to 2 inches (3-5cm) from the patient.
- If it is not focused clearly, rotate lenses with your index finger until the optic disc is as clearly visible as possible.
- The hypermetropic eye requires more plus lenses for clear focus of the fundus; the myopic eye require minus lenses for clear focus.
- Now examine the disc for clarity of outline, colour, elevation and condition of the vessels.
- Follow each vessel as far to the periphery as you can.
- To locate the macula, focus on the disc, then move the light approximately 2 disc diameters temporally.
- You may also have the patient look at the light of the ophthalmoscope, which will automatically place the macula in full view.
- Look for abnormalities in the macula area. The red-free filter facilitates viewing of the centre of the macula.
- If the patient presents with visual loss:
- a. examine the disc for swelling (seen in anterior ischaemic optic neuropathy and central retinal vein occlusion)
- b. examine the vessels for
- tortuosity and dilatation (seen in central retinal vein occlusion)
- narrowing of the vessels (seen in central retinal artery occlusion)
- c. examine the retina for:
- paleness (in retinal artery occlusion)
- haemorrhages (in retinal vein occlusion and diabetic retinopathy.)
- To examine the extreme periphery, instruct the patient to:
- a. look up for examination of the superior retina
- b. look down for examination of the inferior retina
- c. look temporally for examination fo the temporal retina
- d. look nasally for examination fo the nasal retina.
Steps 7 and 8 will reveal almost any abnormality that occur in the fundus.
Tips for better fundal view
Note: in patients who complain of sudden onset floaters, direct ophthalmoscope may not give enough periphery view to locate peripheral tear or hole and referral is recommended especially if you notice any retinal haemorrhages. So, for a better fundal view…
- Corneal reflection can interferes with fundal view. If this is troublesome, this can be overcome with:
- use the polarized filter found in some ophthalmoscope
- small aperture but this reduces the area of the fundus illuminated
- direct the light toward the edge of the pupil rather than directly through its centre.
- Small pupil especially in the elderly.
- Use of short acting dilating drops can increase the area of the fundus examined.
- The most effective combination is tropicamide 1% and phenylepherine 2.5% as they acts on different iris muscle.
- If you can only use one dilating drop instil tropamide which dilate the pupil more efficiently than phenylepherine.
