Iraqi Board Ophthalmology cheat sheet

Snell's law: n1·sin θ1 = n2·sin θ2; total internal reflection occurs when the angle exceeds the critical angle arcsin(n2/n1).

Thin lens equation: 1/f = 1/u + 1/v; power in dioptres P = 1/f (metres). Vergence of a surface = (n2 − n1)/r.

Gullstrand reduced eye: total power ≈ 60 D, axial length 22.22 mm, refractive index 1.333; 1 mm axial change ≈ 3 D refractive change at the spectacle plane.

Spherical equivalent = sphere + ½ cylinder; with-the-rule astigmatism has the steeper meridian vertical (typical in young eyes).

Knapp's law: for axial ametropia, place a correcting lens at the anterior focal point (vertex distance ≈ 15.7 mm) to keep retinal image size unchanged.

Fresnel prism power (Δ) = 100 × tan(deviation angle); 1 prism dioptre deviates a ray 1 cm at 1 m.

Diffraction limit (Rayleigh): angular resolution = 1.22 λ/D; smaller pupil improves aberrations but diffraction dominates below ~2 mm.

Schematic eye: principal planes ~1.6 mm behind cornea; nodal point ~7.1 mm behind cornea - used for retinal image size calculations.

Cycloplegic refraction is mandatory in children under ~12 years and in accommodative esotropia; cyclopentolate 1% is standard, atropine 1% for dark irides or non-response.

Vertex distance conversion: F2 = F1 / (1 − d·F1); significant above ±4 D (d in metres).

Soft contact lens base curve: steeper (smaller) BC fits steeper corneas; typical range 8.3–8.8 mm; overall diameter 13.8–14.5 mm.

RGP fitting: fluorescein pattern shows apical clearance or touch; alignment fit = even, thin edge clearance with mid-peripheral bearing.

Keratoconus: RGP lenses improve BCVA beyond spectacle; steep cones may need Rose K or scleral lenses.

Orthokeratology flattens central cornea by ~1.5–3 D overnight; requires ≥ 0.75 D with-the-rule astigmatism limit for standard designs.

Contact lens complications: microbial keratitis risk highest with extended wear and overnight use; Acanthamoeba linked to tap-water rinsing.

Hydrogel Dk/t: silicone hydrogel Dk > 100; daily wear requires Dk/t ≥ 24, extended wear ≥ 87 (Holden–Mertz criteria).

Corneal layers: epithelium (~50 µm), Bowman's, stroma (~90% thickness), Descemet's (~10 µm at birth, thickens with age), endothelium.

Corneal endothelium: hexagonal monolayer, density ~2500 cells/mm² at birth, declines ~0.5%/year; pump-leak mechanism maintains deturgescence.

Keratoconus signs: inferior steepening, Vogt striae, Fleischer ring (iron), Munson sign; Pentacam Belin/Ambrósio display is the screening standard.

Fuchs endothelial dystrophy: guttata, corneal oedema worse on waking; treatment DSEK/DMEK preferred over penetrating keratoplasty.

Bacterial ulcer: hypopyon, stromal infiltrate; scrape for Gram stain/culture before antibiotics; Pneumococcus and Pseudomonas are common.

Corneal foreign body/abrasion: avoid topical anaesthetic for pain relief (epithelial toxicity); use antibiotic ointment and review in 24–48 h.

Herpes simplex keratitis: dendritic ulcer with terminal bulbs; treat with topical acyclovir or debridement; topical steroids contraindicated in epithelial disease.

Corneal graft rejection: endothelial rejection line (Khodadoust), stromal oedema; treat with frequent topical and systemic steroids.

Anterior uveitis: cells and flare in anterior chamber; HLA-B27, sarcoid, herpes, and trauma are common causes; hypopyon suggests severe inflammation or infection.

Dry eye: Schirmer I < 5 mm/5 min indicates aqueous deficiency; TBUT < 10 s indicates evaporative/mucin deficiency.

Blepharitis: anterior (staphylococcal, seborrhoeic) vs posterior (meibomian gland dysfunction); treat with lid hygiene and warm compresses.

Conjunctivitis: viral (watery, preauricular node), bacterial (purulent), allergic (itchy, cobblestone papillae); avoid steroids in undiagnosed red eye.

Pterygium: fibrovascular growth onto cornea; excision with conjunctival autograft reduces recurrence versus bare sclera.

Scleritis: severe boring pain, violaceous sclera, 50% associated with systemic disease (RA, GPA); anterior non-necrotising most common.

Pinguecula vs pterygium: pinguecula is a yellow conjunctival deposit not crossing the limbus.

Episcleritis: sectoral redness, mild discomfort, blanches with phenylephrine 2.5%; self-limiting, no systemic association in most cases.

Normal IOP 10–21 mmHg; open-angle glaucoma diagnosis requires optic disc/RNFL damage plus field defect, not IOP alone.

Goldmann applanation: IOP = force/area (3.06 mm diameter); underestimates in thin corneas and overestimates in thick corneas.

Primary open-angle glaucoma: cupping > 0.6, neuroretinal rim thinning, nasal step, arcuate scotoma; treat with prostaglandin analogue first-line.

Acute angle-closure: mid-dilated fixed pupil, corneal oedema, IOP often > 40; treat with IV acetazolamide, pilocarpine, topical beta-blocker, then laser peripheral iridotomy.

Optic disc haemorrhage, beta-zone parapapillary atrophy, and disc haemorrhage are risk factors for progression in glaucoma.

Trabeculectomy: mitomycin C reduces scarring; watch for hypotony, bleb leak, endophthalmitis (late complication).

Angle grading: Shaffer 0–4; grade ≤ 2 indicates narrow angle and risk of closure.

Ocular hypertension treatment trial: treat if IOP ≥ 24 with risk factors; 20% IOP reduction reduces progression by ~50%.

Cataract types: nuclear sclerotic (yellow-brown, index myopia), cortical (spokes, glare), posterior subcapsular (posterior opacity, steroid-related).

Biometry: optical (IOLMaster) preferred; A-scan for dense cataracts; SRK/T or Barrett formula; adjust for prior refractive surgery.

Phacoemulsification: divide-and-conquer or chop; capsulorhexis ~5–5.5 mm; aim for in-the-bag IOL placement.

Complications: posterior capsule rupture (PCR), dropped nucleus, endophthalmitis (0.03–0.1%), retinal detachment (higher in high myopia).

Endophthalmitis: presents 3–7 days post-op with pain and hypopyon; treat with intravitreal antibiotics (vancomycin + ceftazidime) after vitreous tap.

Posterior capsular opacification: treat with Nd:YAG laser capsulotomy; risk of retinal detachment and IOL pitting.

Pediatric cataract: operate within first 6–8 weeks for monocular, 8–10 weeks for binocular to prevent amblyopia; aphakia managed with contact lens or IOL.

IOL power calculation: axial length and keratometry are key; post-refractive surgery eyes need history or no-history method (e.g., Barrett True-K).

Diabetic retinopathy: non-proliferative (microaneurysms, dot-blot haemorrhages, hard exudates, cotton wool spots) vs proliferative (NVD, NVE, vitreous haemorrhage).

Diabetic macular oedema: treat with anti-VEGF (ranibizumab, aflibercept) or focal/grid laser for non-centre-involving oedema.

CRVO vs BRVO: CRVO shows diffuse retinal haemorrhages in all quadrants; BRVO is sectoral with a corresponding field defect.

Retinal detachment: rhegmatogenous (tear, photopsia, floaters, field defect), tractional (diabetes, PVR), exudative (serous, no tear).

Central retinal artery occlusion: cherry-red spot, pale retina, sudden painless vision loss; treat with ocular massage, anterior chamber paracentesis, IOP lowering.

Age-related macular degeneration: dry (drusen, geographic atrophy) vs wet (CNV, subretinal fluid, haemorrhage); anti-VEGF for wet AMD.

Retinopathy of prematurity: screening for infants ≤ 30 weeks or ≤ 1500 g; treat type 1 ROP with laser or anti-VEGF.

Vitreous haemorrhage: most common causes are PDR and posterior vitreous detachment; B-scan ultrasound if fundus obscured.

Anterior uveitis: cells/flare, miosis, photophobia; HLA-B27, Behçet, sarcoid, herpes, and trauma are common associations.

Intermediate uveitis: vitritis, snowbanking, pars planitis; associated with MS and sarcoidosis.

Posterior uveitis: retinitis, choroiditis, vasculitis; CMV retinitis (HIV, CD4 < 50), toxoplasmosis (headlight-in-fog lesion), Behçet (occlusive vasculitis).

Sympathetic ophthalmia: bilateral granulomatous uveitis after penetrating trauma; prevent by early enucleation of blind injured eye or primary repair.

Vogt–Koyanagi–Harada: bilateral panuveitis, exudative detachment, meningismus, vitiligo; treat with systemic steroids.

Uveitis workup: CBC, ESR, ACE, chest X-ray, HLA-B27, syphilis serology, TB (QuantiFERON), and Lyme where relevant.

Immunosuppression: steroids first-line; steroid-sparing agents include methotrexate, azathioprine, mycophenolate; biologics (infliximab, adalimumab) for refractory Behçet.

CMV retinitis: 'pizza-pie' or 'brushfire' appearance; treat with ganciclovir, valganciclovir, or foscarnet; check for immune recovery uveitis.

Optic neuritis: unilateral painful vision loss, afferent pupillary defect, dyschromatopsia, disc swelling in ~30%; MS association; treat with IV methylprednisolone for speed of recovery.

Papilloedema: bilateral disc swelling from raised ICP; enlarged blind spot, preserved acuity until late; investigate with MRI/MRV and lumbar puncture.

Third nerve palsy: ptosis, down-and-out eye, mydriasis if compressive (pupil-involving = surgical emergency, posterior communicating artery aneurysm).

Fourth nerve palsy: vertical diplopia worst on downgaze and contralateral gaze; head tilt compensatory; congenital vs traumatic.

Sixth nerve palsy: esotropia, abduction deficit; false localising sign of raised ICP; microvascular most common in adults.

Horner syndrome: ptosis, miosis, anhidrosis; test with apraclonidine; postganglionic causes (carotid dissection) need urgent imaging.

Argyll Robertson pupil: small, irregular, reacts to accommodation but not light; classically neurosyphilis.

Leber hereditary optic neuropathy: bilateral sequential painless vision loss in young males; mitochondrial DNA mutations (m.11778G>A most common).

Orbital cellulitis: fever, proptosis, pain, restricted motility; treat with IV antibiotics; CT to exclude abscess; urgent in children (ethmoid sinus source).

Thyroid eye disease: lid retraction, proptosis, restrictive myopathy (inferior rectus most common); treat with steroids, orbital decompression for severe cases.

Orbital fracture: blowout fracture shows enophthalmos, restricted upgaze, and orbital floor defect on CT; trapdoor fracture in children is an emergency.

Ptosis: congenital (levator maldevelopment), aponeurotic (involutional), myogenic (myasthenia), neurogenic (Horner, third nerve); treat with levator resection or frontalis sling.

Dacryocystitis: painful medial canthal swelling; treat with antibiotics and warm compresses; dacryocystorhinostomy (DCR) for chronic obstruction.

Epiphora: assess with Jones dye test, syringing, and dacryocystography; common causes are nasolacrimal duct obstruction and punctal stenosis.

Orbital tumours: capillary haemangioma (children), cavernous haemangioma (adults), lymphoma (older adults, moulding around structures), rhabdomyosarcoma (children, rapid growth).

Enucleation vs evisceration: evisceration retains sclera and may give better motility; enucleation required for intraocular malignancy.

Amblyopia: reduced acuity without organic cause; treat with occlusion or atropine penalisation; critical period up to ~8–10 years.

Esotropia: accommodative (hypermetropia, treat with glasses), infantile (onset < 6 months, treat with surgery), and intermittent (convergence excess).

Exotropia: intermittent most common; surgery if decompensating or causing symptoms; check for underlying disease.

Strabismus surgery: recession weakens, resection strengthens; adjustable sutures for adults; risk of anterior segment ischaemia with multiple muscles.

Leukocoria: retinoblastoma, congenital cataract, ROP, Coats disease, toxocariasis; urgent B-scan and paediatric oncology referral.

Congenital glaucoma: buphthalmos, corneal oedema, photophobia, tearing; treat with goniotomy or trabeculotomy.

Retinopathy of prematurity: stages 1–5; plus disease indicates type 1 ROP requiring treatment.

Anisometropia: difference > 1 D increases amblyopia risk; treat with refractive correction and occlusion.

Retinoblastoma: leukocoria, strabismus; calcification on CT; genetic (RB1 mutation) vs sporadic; treat with chemotherapy, laser, cryotherapy, enucleation.

Uveal melanoma: pigmented choroidal mass, ultrasonography shows low internal reflectivity; treat with plaque brachytherapy, proton beam, or enucleation.

Conjunctival melanoma: pigmented lesion, biopsy required; treat with excision and cryotherapy; monitor for recurrence.

Squamous cell carcinoma of conjunctiva: gelatinous or leukoplakic lesion; treat with excision, cryotherapy, topical mitomycin C or 5-FU.

Basal cell carcinoma: most common eyelid malignancy; pearly nodule with telangiectasia; treat with excision with margin control.

Sebaceous gland carcinoma: yellow lid mass, madarosis, pagetoid spread; biopsy with lipid stain; can mimic blepharitis.

Choroidal naevus vs melanoma: naevus is flat, < 2 mm thick, drusen; melanoma shows growth, subretinal fluid, orange pigment, thickness > 2 mm.

Orbital lymphoma: older adults, salmon-patch conjunctival lesion, moulds around structures; treat with radiotherapy or chemotherapy.

Chemical injury: irrigate with copious saline for at least 30 minutes; check pH; treat with topical steroids and antibiotics; urgent ophthalmology review.

Open globe: do not remove protruding foreign bodies; shield eye, avoid pressure, give IV antibiotics and tetanus prophylaxis, and proceed to theatre.

Hyphema: bed rest, head elevation, avoid NSAIDs/aspirin; check for rebleed at 3–5 days; treat with topical steroids and cycloplegics.

Orbital compartment syndrome: proptosis, tense orbit, afferent pupillary defect; emergency lateral canthotomy and cantholysis.

Traumatic optic neuropathy: suspect with afferent pupillary defect after trauma; high-dose steroids controversial; consider optic canal decompression.

Intraocular foreign body: CT scan for metallic; avoid MRI if metallic; remove via pars plana vitrectomy.

Corneal abrasion: treat with antibiotic ointment and review; avoid topical anaesthetics; consider bandage contact lens for large defects.

Endophthalmitis after trauma: pain, hypopyon, decreased vision; treat with intravitreal antibiotics and vitrectomy if severe.

OCT: high-resolution cross-sectional imaging of retina and optic nerve; used for macular oedema, CNV, and RNFL thickness in glaucoma.

Fluorescein angiography: evaluates retinal vascular leakage, CNV, and capillary non-perfusion; side effects include nausea and rare anaphylaxis.

Indocyanine green angiography: better for choroidal vasculature; used in AMD and polypoidal choroidal vasculopathy.

Visual field testing: Humphrey 24-2 or 30-2; reliability indices (fixation losses, false positives/negatives); pattern deviation for glaucoma.

B-scan ultrasound: useful when fundus obscured (vitreous haemorrhage, dense cataract); detects retinal detachment and intraocular tumours.

CT vs MRI: CT better for bone and calcification (retinoblastoma, foreign bodies); MRI better for soft tissue and optic nerve.

Electrophysiology: ERG for retinal dystrophies, VEP for optic nerve disease, EOG for Best disease.

Corneal topography/Pentacam: maps curvature and elevation; essential for keratoconus screening and refractive surgery planning.

Preoperative assessment: history of anticoagulants, alpha-blockers (floppy iris syndrome), and allergies; fasting guidelines per local protocol.

Anticoagulation: aspirin and warfarin usually continued for cataract surgery; clopidogrel may be continued; check INR if on warfarin.

Prophylaxis: topical antibiotics before and after cataract surgery; intracameral cefuroxime reduces endophthalmitis risk.

Anaesthesia: topical ± intracameral lidocaine for phaco; peribulbar/retrobulbar for complex cases; check for globe perforation in high myopia.

Postoperative review: day 1 check acuity, IOP, and wound; watch for endophthalmitis, wound leak, and corneal oedema.

Floppy iris syndrome: associated with tamsulosin; warn patients, use intracameral phenylephrine and iris hooks.

Steroid response: monitor IOP after topical steroids; treat with IOP-lowering agents if elevated.

Patient counselling: discuss risks of surgery, expected visual outcome, and the need for postoperative drops and follow-up.

Levels of evidence: systematic reviews/meta-analyses > randomised controlled trials > cohort > case-control > case series > expert opinion.

Number needed to treat (NNT) = 1 / absolute risk reduction; useful for comparing interventions.

Sensitivity and specificity: sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Consent: must be informed, voluntary, and given by a competent patient; document risks, benefits, and alternatives.

Confidentiality: patient data must be protected; disclose only with consent or legal requirement.

Conflict of interest: declare financial or personal interests that may affect clinical decisions or research.

Research ethics: institutional review board approval, informed consent, and adherence to Declaration of Helsinki.

Audit vs research: audit evaluates practice against standards; research generates new knowledge and requires ethical approval.

Visual acuity: Snellen or logMAR; pinhole improves refractive error; record with and without correction.

Pupil examination: check size, shape, direct and consensual reflex, and swinging flashlight test for afferent pupillary defect.

Slit lamp: examine lids, conjunctiva, cornea, anterior chamber, iris, and lens; use fluorescein for corneal epithelial defects.

Tonometry: Goldmann applanation is gold standard; Tonopen for irregular corneas; avoid in suspected open globe.

Gonioscopy: assess angle with Shaffer grading; use a mirrored lens; essential in glaucoma and trauma.

Fundoscopy: direct ophthalmoscope for disc and macula; indirect for peripheral retina; document cup-disc ratio and vessel changes.

Amsler grid: detects metamorphopsia in macular disease; patient self-monitoring tool.

Colour vision: Ishihara plates for red-green defects; Farnsworth-Munsell for more detailed assessment.

Premedication: avoid routine sedation in elderly; consider antiemetics for patients with motion sickness or prior PONV.

Local anaesthesia: check for allergy to ester/amide; use hyaluronidase to improve spread; avoid in infected tissue.

Intraoperative floppy iris: use iris hooks or pupil expansion rings; intracameral phenylephrine helps.

Postoperative endophthalmitis prevention: povidone-iodine 5% conjunctival prep, sterile drapes, intracameral cefuroxime.

Wound construction: clear corneal incisions should be watertight; suture if leak persists; check Seidel test.

Postoperative IOP spike: common after viscoelastic use; monitor and treat with topical agents or oral acetazolamide if severe.

Discharge instructions: use drops as prescribed, avoid eye rubbing, and return if pain or vision loss occurs.

Documentation: record consent, anaesthesia, procedure, complications, and postoperative plan.

Randomised controlled trials: randomisation reduces selection bias; blinding reduces measurement bias; intention-to-treat analysis preserves randomisation benefits.

Confidence intervals: 95% CI indicates range likely containing true effect; narrower CI means more precision.

P-values: probability of observed result if null hypothesis true; not a measure of effect size.

Meta-analysis: combines studies; check for heterogeneity (I² statistic) and publication bias (funnel plot).

Clinical practice guidelines: based on systematic reviews; adapt to local resources and patient preferences.

Ethical principles: autonomy, beneficence, non-maleficence, justice; apply to consent and resource allocation.

Professionalism: maintain competence, honesty, and patient welfare above self-interest; report impaired colleagues.

Telemedicine: ensure privacy, informed consent, and appropriate documentation; not a substitute for in-person examination when needed.

Corneal ulcer management: identify organism, start broad-spectrum antibiotics (fortified cefazolin + tobramycin), review daily; add antifungal if fungal suspected.

Fungal keratitis: feathery margins, satellite lesions, hypopyon; treat with natamycin 5% or voriconazole; avoid steroids initially.

Acanthamoeba keratitis: contact lens wearer, severe pain out of proportion, ring infiltrate; treat with polyhexamethylene biguanide and propamidine.

Corneal dystrophies: epithelial basement membrane (map-dot-fingerprint), granular, lattice, macular; genetic counselling and keratoplasty for advanced cases.

Keratoplasty types: PK (full thickness), DALK (stroma), DSEK/DMEK (endothelium); DALK preserves endothelium and reduces rejection.

Corneal perforation: treat with cyanoacrylate glue, bandage contact lens, or tectonic keratoplasty; systemic antibiotics if infected.

Dry eye: artificial tears, punctal plugs, cyclosporine; treat meibomian gland dysfunction with lid hygiene and omega-3.

Corneal neovascularisation: treat underlying cause; topical steroids and anti-VEGF may help; avoid contact lens overwear.

Angle-closure glaucoma: laser peripheral iridotomy is definitive for pupillary block; treat acute attack with IOP-lowering agents first.

Primary open-angle glaucoma: prostaglandin analogues increase uveoscleral outflow; beta-blockers reduce aqueous production; alpha-agonists and carbonic anhydrase inhibitors are adjuncts.

Glaucoma progression: monitor with visual fields and OCT RNFL; disc haemorrhage and thin central corneal thickness are risk factors.

Normal-tension glaucoma: IOP within normal range but glaucomatous damage; treat with IOP lowering and investigate systemic associations.

Secondary glaucoma: pseudoexfoliation, pigment dispersion, neovascular, uveitic, and steroid-induced; treat underlying cause.

Surgical options: trabeculectomy, glaucoma drainage devices (Ahmed, Baerveldt), MIGS (iStent, Hydrus) for mild-moderate disease.

Pediatric glaucoma: buphthalmos, corneal oedema; treat with goniotomy or trabeculotomy; monitor for amblyopia.

Glaucoma screening: not recommended for general population; target high-risk groups (family history, older age, African ancestry).

Cataract grading: LOCS III system for nuclear colour, cortical, and posterior subcapsular opacities.

Biometry formulas: SRK/T for average eyes; Hoffer Q for short eyes; Haigis for post-refractive surgery; Barrett Universal II widely used.

Phacoemulsification: maintain anterior chamber with viscoelastic; avoid anterior capsule tear; aim for in-the-bag IOL.

Complications: posterior capsule rupture, vitreous loss, dropped nucleus, endophthalmitis, retinal detachment, and cystoid macular oedema.

Endophthalmitis: treat with intravitreal vancomycin and ceftazidime; vitrectomy if severe; prevent with povidone-iodine and intracameral antibiotics.

Posterior capsular opacification: Nd:YAG capsulotomy; risk of retinal detachment and IOL damage; use lowest effective energy.

Pediatric cataract: early surgery to prevent amblyopia; postoperative refractive correction and occlusion therapy.

IOL types: monofocal, multifocal, toric, and extended depth of focus; discuss dysphotopsia and spectacle independence.

Diabetic retinopathy screening: annual dilated fundoscopy; refer for proliferative disease or macular oedema.

Anti-VEGF: ranibizumab, aflibercept, bevacizumab; used for DME, wet AMD, and RVO; monitor for endophthalmitis and IOP rise.

Retinal detachment: rhegmatogenous repair with scleral buckle or vitrectomy; pneumatic retinopexy for suitable cases.

Macular hole: stages 1–4; treat with vitrectomy and gas tamponade; face-down positioning may improve closure.

Epiretinal membrane: macular pucker; vitrectomy with membrane peeling for symptomatic cases.

Central serous chorioretinopathy: serous detachment in young males; associated with steroids; observe or treat with PDT.

Retinopathy of prematurity: screening and treatment with laser or anti-VEGF; monitor for recurrence.

Vitreous haemorrhage: B-scan if fundus obscured; treat underlying cause; vitrectomy for non-clearing haemorrhage.

Anterior uveitis: topical steroids and cycloplegics; investigate if recurrent or bilateral.

Intermediate uveitis: treat with periocular or systemic steroids; consider immunomodulation for chronic cases.

Posterior uveitis: identify infectious vs non-infectious; treat with antimicrobials or immunosuppression accordingly.

Behçet disease: oral ulcers, genital ulcers, uveitis; treat with systemic steroids and biologics (infliximab).

Toxoplasmosis: classic focal retinochoroiditis; treat with pyrimethamine and sulfadiazine plus folinic acid; steroids after antimicrobial cover.

CMV retinitis: treat with ganciclovir, valganciclovir, or foscarnet; monitor for immune recovery uveitis.

Sympathetic ophthalmia: bilateral granulomatous uveitis after trauma; treat with systemic steroids and immunosuppression.

VKH: systemic steroids; monitor for complications (cataract, glaucoma, choroidal neovascularisation).

Optic neuritis: IV methylprednisolone speeds recovery but does not change final acuity; MRI for MS risk stratification.

Papilloedema: investigate with MRI/MRV and lumbar puncture; treat underlying cause; weight loss for idiopathic intracranial hypertension.

Third nerve palsy: pupil-involving = urgent imaging for aneurysm; pupil-sparing = microvascular until proven otherwise.

Fourth nerve palsy: congenital vs acquired; treat with prisms or surgery; check for head tilt.

Sixth nerve palsy: microvascular most common; investigate if bilateral, progressive, or in children.

Horner syndrome: test with apraclonidine; postganglionic causes need carotid imaging.

Leber hereditary optic neuropathy: mitochondrial inheritance; no effective treatment; genetic counselling.

Visual field defects: bitemporal hemianopia (chiasm), homonymous hemianopia (retrochiasmal), and quadrantanopia localise lesions.

Orbital cellulitis: IV antibiotics; CT to exclude abscess; urgent in children.

Thyroid eye disease: steroids, orbital decompression, and strabismus surgery for restrictive myopathy.

Blowout fracture: CT for floor defect; repair if enophthalmos > 2 mm or persistent diplopia.

Ptosis: levator function > 8 mm = levator resection; < 4 mm = frontalis sling.

Dacryocystitis: antibiotics and warm compresses; DCR for chronic obstruction.

Epiphora: Jones dye test, syringing, and dacryocystography; treat underlying cause.

Orbital tumours: imaging with CT/MRI; biopsy for diagnosis; multidisciplinary management.

Enucleation vs evisceration: evisceration for blind painful eye; enucleation for intraocular malignancy.

Amblyopia: occlusion or atropine; treat before age 8–10 for best results.

Esotropia: accommodative (glasses), infantile (surgery), intermittent (observation or surgery).

Exotropia: intermittent most common; surgery if decompensating.

Strabismus surgery: recession weakens, resection strengthens; adjustable sutures for adults.

Leukocoria: urgent referral; retinoblastoma, cataract, ROP, Coats disease.

Congenital glaucoma: buphthalmos, corneal oedema; goniotomy or trabeculotomy.

ROP: screening for preterm infants; treat type 1 ROP with laser or anti-VEGF.

Anisometropia: refractive correction and occlusion for amblyopia.

Retinoblastoma: leukocoria, calcification on CT; treat with chemotherapy, laser, cryotherapy, enucleation.

Uveal melanoma: pigmented choroidal mass, low internal reflectivity; plaque brachytherapy or enucleation.

Conjunctival melanoma: biopsy and excision with cryotherapy; monitor for recurrence.

Squamous cell carcinoma: gelatinous lesion; excision, cryotherapy, topical mitomycin C.

Basal cell carcinoma: pearly nodule; excision with margin control.

Sebaceous gland carcinoma: yellow lid mass, madarosis; biopsy with lipid stain.

Choroidal naevus vs melanoma: growth, subretinal fluid, orange pigment, thickness > 2 mm.

Orbital lymphoma: salmon patch, moulds around structures; radiotherapy or chemotherapy.

Chemical injury: irrigate for at least 30 minutes; check pH; topical steroids and antibiotics.

Open globe: shield eye, avoid pressure, IV antibiotics, tetanus, theatre.

Hyphema: bed rest, head elevation, avoid NSAIDs; check for rebleed.

Orbital compartment syndrome: lateral canthotomy and cantholysis.

Traumatic optic neuropathy: suspect with APD; steroids controversial.

Intraocular foreign body: CT for metallic; avoid MRI; remove via vitrectomy.

Corneal abrasion: antibiotic ointment; avoid topical anaesthetics.

Endophthalmitis after trauma: intravitreal antibiotics and vitrectomy if severe.

OCT: macular oedema, CNV, RNFL thickness.

Fluorescein angiography: leakage, CNV, non-perfusion; rare anaphylaxis.

Indocyanine green: choroidal vasculature; AMD and PCV.

Visual fields: Humphrey 24-2/30-2; reliability indices; pattern deviation.

B-scan: fundus obscured; retinal detachment, tumours.

CT vs MRI: CT for bone/calcification; MRI for soft tissue/optic nerve.

Electrophysiology: ERG, VEP, EOG for dystrophies and optic nerve disease.

Topography/Pentacam: keratoconus screening and refractive surgery planning.

Preoperative: anticoagulants, alpha-blockers, allergies; fasting per protocol.

Anticoagulation: aspirin and warfarin usually continued; check INR.

Prophylaxis: topical antibiotics; intracameral cefuroxime reduces endophthalmitis.

Anaesthesia: topical ± intracameral lidocaine; peribulbar for complex cases.

Postoperative review: day 1 acuity, IOP, wound; watch for endophthalmitis.

Floppy iris: tamsulosin; intracameral phenylephrine and iris hooks.

Steroid response: monitor IOP; treat if elevated.

Counselling: risks, benefits, drops, follow-up.

Levels of evidence: systematic reviews > RCTs > cohort > case-control > case series.

NNT = 1 / absolute risk reduction.

Sensitivity = TP / (TP + FN); specificity = TN / (TN + FP).

Consent: informed, voluntary, competent; document risks and alternatives.

Confidentiality: protect patient data; disclose only with consent or legal requirement.

Conflict of interest: declare financial or personal interests.

Research ethics: IRB approval, informed consent, Declaration of Helsinki.

Audit vs research: audit evaluates practice; research generates new knowledge.