Ophthalmology - OMSB Specialty Training Exam
The OMSB Ophthalmology exit examination samples the full specialty syllabus: cornea and external disease, glaucoma, lens and cataract, retina and vitreous, uveitis, neuro-ophthalmology, pediatric ophthalmology and strabismus, oculoplastics, refractive surgery, plus applied optics, ocular pharmacology and basic science. Vignettes dominate, and marks go to a defensible clinical sequence rather than isolated facts.
A fixed examination sequence
Record visual acuity first, then pupils (size, reaction, relative afferent pupillary defect), motility and alignment, confrontation fields, slit-lamp examination, intraocular pressure, and finally dilated fundoscopy. Changing the order - dilating before assessing the pupil or anterior chamber depth - is a common, avoidable error. In trauma, exclude a ruptured globe before any pressure measurement.
Compartment-based reasoning
Treat anterior disease topically and posterior disease periocularly or intravitreally; know the systemic drugs that alter ocular status (steroids, anticholinergics, hydroxychloroquine, ethambutol, amiodarone). A painful red eye with reduced acuity is sight-threatening until excluded: think acute angle closure, microbial keratitis, uveitis, endophthalmitis and scleritis before conjunctivitis.
Worked example
A 62-year-old man has four hours of severe left eye pain, halos and vomiting. Visual acuity is 6/60 on the left, the pupil is mid-dilated and fixed, the cornea hazy and the anterior chamber shallow; intraocular pressure is 54 mmHg. Reasoning: acute pain with halos, reduced acuity, a fixed mid-dilated pupil and a shallow chamber identifies acute angle-closure glaucoma, not uveitis or conjunctivitis. Treat immediately with a topical beta-blocker and alpha-agonist, systemic acetazolamide, and an intravenous hyperosmotic agent if pressure stays high. Add pilocarpine only after the pressure falls, because an ischaemic iris sphincter will not respond. Definitive treatment is laser peripheral iridotomy, with prophylactic treatment of the fellow eye.
Traps that cost marks
- Missing giant cell arteritis in a patient over 50 with anterior ischaemic optic neuropathy; ask about jaw claudication and scalp tenderness and start steroids before investigations.
- Prescribing a topical steroid for a dendritic ulcer without antiviral cover.
- Diagnosing papilloedema without checking blood pressure and visual function, or omitting the relative afferent pupillary defect in unilateral optic neuropathy.