Surgery Procedures PDF

Surgery Nystagmus -- Rectus muscle recession and resection - Surgery on all four recti muscles\ Face turn to right, null zone to left\ Surgery moves BEs in direction of CHP to centre the null zone - Face turn to the right\ RLR 8mm resection RMR 5mm recession LMR 6mm rese...

Surgery Nystagmus -- Rectus muscle recession and resection - Surgery on all four recti muscles\ Face turn to right, null zone to left\ Surgery moves BEs in direction of CHP to centre the null zone - Face turn to the right\ RLR 8mm resection RMR 5mm recession LMR 6mm resection LLR 7mm recession - Usually improves but may not abolish CHP\ Effect may not last\ May improve vision\ Most patients will not reach driving standard Subretinal fluid drainage -- retinal detachment - Drainage of fluid via the sclera\ for deep / longstanding SRF\ Not done frequently --\ complications include retinal\ perforation +/- incarceration\ in the entry site RD surgery -- pars plana vitrectomy (PPV)\ When? With giant tears, very large breaks, or PVR (where scleral\ buckling unlikely to work)\ Cut and aspirate vitreous\ Infusion of saline to maintain the vitreous cavity pressure and volume\ Tamponading agents -- expanding gases or silicone oil\ Complications\ Raised IOP -- gas expansion, oil blocking trabecular meshwork,\ secondary glaucoma (ghost cell, inflammatory, steroid-induced)\ Cataracts\ Band keratopathy RD surgery -- scleral buckling\ Scleral buckling, or conventional/external\ RD surgery\ Silicone sutured onto the sclera (an\ explant) which creates an inwards\ indentation. Closes RD by apposing RPE\ to the sensory retina\ Complications -- transient IOP spikes and\ diplopia, CMO, buckle extrusion /\ intrusion / infection, choroidal\ detachment\ Must catch all breaks or a high risk of\ failure RD surgery -- vitrectomy and retinopexy\ Vitrectomy\ 3 ports - infusion cannula, vitreous cutter, and fibreoptic light probe\ Remove the central vitreous gel and posterior hyaloid face\ Pneumatic retinopexy\ For small breaks\ Inject a gas bubble\ Then use laser / cryo to seal breaks Cataract surgery - phacoemulsification\ Anaesthesia\ Povidone-iodine 5% or chlorhexidine instillation and eyelid cleaning\ Draping and speculum insertion\ Creation of 1-2 side ports and the main corneal incision\ Viscoelastic into the AC Capsulorhexis: femto laser, cystotome (bent hypodermic needle), forceps\ Hydrodissection: insert fluid under capsulorhexis to separate lens from capsule\ Divide and conquer / phaco chop\ Removal of lens cortex: vacuum carefully peels away from capsule and aspirated Cataract surgery - phacoemulsification\ IOL insertion -- viscoelastic\ Wound sealing -- hydrosealing (stromal\ saline injection), stepped approach (typically\ no sutures required)\ Prophylactic Abx\ intracamerally/subconjunctivally\ Femtosecond lasers: more precise with slightly improved refractive outcomes, but\ costly, difficult to learn, time-consuming Other types of cataract surgery\ Extracapsular cataract extraction (ECCE) -- large anterior capsulotomy with large\ limbal incision\ Intracapsular cataract extraction (ICCE) -- cryoprobe removes entire lens and\ capsule\ Manual small-incision cataract surgery (MSICS) -- used for high volume clinics in\ developing countries, creation of a scleral tunnel Cataract surgery -- intra-operative complications\ Damage to the iris or cornea\ Corneal epithelial abrasion, endothelial damage/Descemet's tear, iris damage\ Damage to the capsule - posterior capsule rupture (PCR)\ With or without loss of some of the vitreous jelly inside the eye\ PCR causes increased risk of poor visual outcome and complications\ including CMO, retinal detachment, infection, inflammation\ Loss of all or part of the cataract or the implant into the back of the eye which\ may require a further operation (dropped nucleus or cataract lens fragments).\ Bleed (suprachoroidal haemorrhage): ruptured posterior ciliary artery; can result\ in expulsion of intraocular contents\ Endophthalmitis Cataract surgery -- post op review\ Post-op instructions:\ Instil all post-op drops as specified (Abx and steroids)\ Avoid: rubbing/touching eye, dusty/dirty environments, no water or soap in the\ eye (washing hair), no swimming for 2/52,no bending to pick heavy objects, no\ eye makeup\ Can resume light exercise and everyday activities within 2-3/7\ Mild discomfort (watering, gritty sensation, some light sensitivity) is normal\ May get diplopia initially Cataract surgery -- post op review\ When you see them\...\ Is the vision what you expect it to be?\ Unexplained reduced vision\ Was there a guarded prognosis?\ Do they need listing for the second eye?\ Symptomatic cataract\ VA \6/12 Cataract surgery -- post-operative endophthalmitis\ Severe inflammation that can lead to total loss of vision\ Symptoms: painful red eye and significant loss of vision\ Signs: lid oedema and chemosis, significant conj hyperaemia,\ corneal haze, AC activity (cells, flare / fibrinous exudate,\ hypopyon), vitritis\ Differentials: retained lens material, vitreous haem, severe\ p/o uveitis (from complicated / prolonged surgery)\ Management in HES: sample aqueous and vitreous for\ culture to identify the pathogen, then IV + systemic Abx,\ topical and systemic steroids, pars plana vitrectomy\ Prognosis? Depends on VA at presentation -- if PL then 1/3\ may achieve up to 6/12, if better than PL then up to 2/3 may\ achieve this How soon to refer post-op complications?\ Emergency: suspected endophthalmitis\ Urgent\ Retinal detachment/retinal tear\ Wound closure problems\ Marked or persistent mild/moderate iritis\ IOP\>28mmHg\ Unexpected IOL displacement +/- refractive surprise\ Corneal oedema, cystoid macular oedema, severe diabetic retinopathy\ Drop allergy\ Routine: significant symptomatic PCO, patient not happy with vision/refractive\ outcome/comfort Photodynamic therapy (PDT)\ ▪ Photodynamic therapy (PDT) with verteporfin has largely been\ replaced by anti VEGF for more patients\ ▪ May be used either in combination with anti VEGF or PDT alone\ (rarely)\ ▪ It may also be used for a chronic central serous chorioretinopathy Photodynamic therapy (PDT) action\ ▪ Intravenous injection of verteporfin (visudyne)\ ▪ Verteporfin preferentially taken up by the CNV membrane, not the\ retina, hence no retinal damage\ ▪ Drug is activated by low powered laser causing damage to\ proliferating cells and seals/regresses leaking vessels.\ ▪ Usually painless for the patient Anti-VEGF\ ▪ Vascular endothelial growth factor (VEGF) is a protein that triggers\ the formation of new blood vessels\ ▪ Anti VEGF drugs bind with VEGF to prevent the trigger for abnormal\ blood vessel growth and leakage\ ▪ Anti VEGF drugs are administered via intravitreal injection Anti-VEGF\ ▪ NICE recommends for patients with:\ ▪ Evidence of progressive wet AMD\ ▪ VA between 6/12 and 6/96\ ▪ No structural damage to the fovea\ ▪ From clinical experience:\ ▪ Refer patients with suspected wet AMD regardless of their level of\ vision\ ▪ Patients with VA better than 6/12 or worse than 6/96 may be\ considered for treatment off license in certain clinical\ circumstances\ ▪ Most patients are suitable for anti VEGF \~ 90% Maculopathy (M1): management\ ARGON green laser-energy\ absorbed by & destroys\ micro-aneurysms\ Closes leakage site\ Encourages exudates\ absorption & oedema\ resolution\ May destroy surrounding area\ Poor response shown with\ ischaemic maculopathy Non-proliferative (R2, severe) ◊ Prevent progression to R3\ LASER Pan-Retinal Photocoagulation (PRP) -- scatter pattern\ -- reduce O2 demand of retina by tissue destruction, inhibits NV growth ◊ regression\ -- \>\> scarring & peripheral visual field loss (up to 40-50% reduction of visual field)\ -- tritan colour vision defect ? Laser Iridotomy\ Mode of Action: Treatment of primary angle\ closure glaucoma (or secondary angle closure\ with pupil block).\ What is it?\ Laser used to create a small hole in the iris\ (usually under the eyelid between 11 and 1\ o'clock position to reduce diplopia/glare). Management:\ Patient should lie down\ Acetazolamide 500mg (IV if IOP \>50mmHg;\ orally if IOP\ 24mmHg and chose not to have SLT/ SLT is not suitable/are waiting for SLT:\ Prostaglandin analogue eye drops (First choice)\ Topical beta blocker (second choice)\ Carbonic anhydrase inhibitors\ Or a combination of treatments.\ Management Laser Trabeculoplasty Mode of action: delivery of laser to the trabecular meshwork in order to increase aqueous outflow\ thus reduce IOP.\ Examples:\ Selective laser trabeculoplasty (SLT): First line treatment for Glaucoma (NG81)\ Argon laser trabeculoplasty (laser burns to increase IOP reduction)\ Micro pulse laser trabeculoplasty\ Usage: Primary and secondary open angle glaucoma; Ocular Hypertension. Selective Laser Trabeculoplasty First line treatment for Primary Open Angle Glaucoma and Ocular Hypertension.\ Mechanism of Action: Low energy light targeting melanin rich cells in the aqueous chamber. This\ results in an immune response whereby white blood cells clear the affected cells and rebuild the\ trabecular meshwork- thus restoring its functionality.\ Benefits: Reduced ocular and systemic side effects, No tissue damage, reduced need for medication\ (particularly useful when problems with adherence or drop use). Prostaglandin Analogues Mechanism of Action: Increases uveoscleral outflow. Reduces IOP 27-35% from baseline.\ Examples: Latanoprost, Travoprost, Bimatoprost, Tafluprost\ Side effects:\ Skin (reversible) & iris (irreversible) hyperpigmentation\ Excessive eyelash growth\ Cystoid Macular Oedema\ Conjunctival hyperaemia\ Avoid in pregnancy: Risk of spontaneous abortion? Beta blockers Mechanism of Action: Decrease Aqueous production. Reduce IOP 21-27% from baseline.\ Examples: Timolol, Betaxolol, Carteolol, Metripranolol\ Side effects:\ Ocular Side Effects: allergy, punctate corneal erosions, reduced aqueous secretion, Decreased\ corneal sensitivity (prolonged use)\ Systemic: Bradycardia (reduced heart rate), Arrhythmia (irregular heartbeat), Heart failure,\ Bronchospasm (tightening of the muscles that line airways). Syncope (feeling faint), Nocturnal\ hypotension (reduced blood pressure at night)- thus should avoid instillation during bedtime.,\ Headache, and depression.\ Contraindications: Asthma, COPD, bradycardia, heart failure, Normal tension glaucoma Alpha 2 agonists Mechanisms of Action: decreases aqueous production and increases uveo-scleral outflow\ Examples: Brimonidine, Apraclonidine\ Contraindications: Children under 2 years old, accompanying oral monoamine oxidase inhibitor anti-\ depressants (as they can cause hypotensive crisis).\ Note: As these drugs cross the blood-brain barrier and thus caution should be taken in young children\ who have central nervous system depression and hypotension Carbonic Anhydrase Inhibitors Mechanism of action: Inhibit aqueous secretion.\ Examples: Dorzolamide, Brinzolamide\ Side effects: Blurred vision, induced myopia\ Contraindications: sulphonamide allergy, renal impairment, take caution with individuals with corneal\ endothelial dysfunction as these precipitate corneal decompensation in these patients Miotics Mechanism of action:\ 1. The contraction of the sphincter pupillae pulls the peripheral iris away from the trabecular\ meshwork thus opening the anterior chamber angle, in the case of angle closure.\ 2. Contract the ciliary muscle -- thus increasing aqueous outflow through the trabecular meshwork.\ Example: Pilocarpine\ Side effects: brow ache, miosis, myopic shift, increase in cataract symptoms, confusion, bradycardia,\ bronchospasm, and gastrointestinal symptoms.\ Note that systemic side effects are rare