Ocular oncology, trauma, and systemic disease associations
This domain mixes two themes: tumours of the eye and adnexa, where the key is benign versus malignant and biopsy versus observation; and trauma and systemic disease, where the key is urgent, protocolised management.
Intraocular and adnexal tumours
Choroidal melanoma is the commonest primary intraocular malignancy in adults: pigmented dome or mushroom lesion, subretinal fluid, orange pigment, thickness over 2 mm; treat with plaque brachytherapy, proton beam or enucleation. Metastasis is the commonest intraocular tumour overall and is usually pale and multifocal. Retinoblastoma is calcified and occurs in children; primary vitreoretinal lymphoma masquerades as uveitis. Conjunctival melanoma arises from primary acquired melanosis with atypia; ocular surface squamous neoplasia arises at the limbus; basal cell carcinoma is the commonest lid malignancy, with sebaceous carcinoma as the dangerous mimic.
Trauma
Chemical injury is the true emergency: irrigate copiously, check pH until neutral, remove particles, and grade by limbal ischaemia; use ascorbate, citrate and early amniotic membrane. Open globe: shield, no pressure, antibiotics, surgery. Hyphaema: rest, treat pressure, and remember carbonic anhydrase inhibitors can worsen sickle cell disease. Blow-out fracture: restricted upgaze, enophthalmos, and a decision for surgery. Sympathetic ophthalmia follows penetrating trauma and is prevented by timely enucleation of a blind eye.
Systemic associations
Diabetes, hypertension, sarcoidosis, thyroid disease, syphilis and HIV have signature findings. Drug toxicity is heavily examined: hydroxychloroquine bull's eye maculopathy, ethambutol optic neuropathy, amiodarone corneal deposits, topiramate acute myopia with angle closure, and corticosteroids causing cataract and glaucoma.
Worked example
A farmer has an alkaline splash with extreme pain, limbal blanching and a hazy cornea. Reasoning: the extent of limbal ischaemia grades severity and predicts stem cell failure, so irrigate immediately and for a prolonged period, give medical therapy, and plan amniotic membrane or stem cell transplantation rather than waiting.
Traps
Pressurising an open globe; giving acetazolamide in sickle cell hyphaema; missing drug-induced maculopathy on screening; assuming every pigmented choroidal lesion is melanoma without ultrasound follow-up.