Competency 6.1.11 Flashcards
Systemic Cataract Preoperative Considerations
Can patient lie flat?
- COPD where lying supine may cause shortness of breath
- Spinal abnormalities
Alpha blockers
- Tamulosin and naftopidil can cause floppy iris syndrome
Allergy
- Allergy to shellfish may indicate iodine allergy
Ocular Cataract Preoperative Considerations
Deep set eyes & shallow AC
- can make surgery more difficult
Lids and Adnexa
- Blepharitis or lid malposition can predispose to endophthalmitis
Fundus Examination
- Coexisting pathology can impact visual outcome
Refraction
- Consider K values, AL and refraction to leave patient at emmetropia
- Consider any previous refractive suprise
- Consider previous laser eye surgery
What is Phacoemulsification?
- Is standard method of cataract surgery
- Is a device which breaks up the lens using ultrasonic waves which can then be vacuumed out
- Surgery is a 30 minute affair which takes place under local anaesthetic
Phacoemulsification Procedure
- Incisions either 60 or 180 degrees apart at limbus to allow access
- Opening of anterior lens capsule (capsularhexis)
- Removal of lens material using phaco, many techniques including divide and conquer
- Removal of lens material
- Insertion of IOL into lens caspsule
- Incisions may be sealed with stromal saline injection
Extracapsular Cataract Extraction
- Requires larger incision and so has slower recovery rate
- Used in very dense cataract where higher phaco powers would potentially cause issues
- The larger incision allows the cataract to be removed in one piece.
- requires stitches after surgery
Post Surgery Pharmacological Treatment
- Dexamethasone 0.1% or prednisolone 1.0% bds for 4 weeks
- Chloramphenicol bds for 4 weeks
- May be given topical NSAID if diabetic
Post Surgery Non-Pharmacological Treatment
- Eye shield to wear every night for first week after surgery to protect eye during night can also be used in shower to protect when washing hair
Post Surgical Advice
- No swimming for 4 to 6 weeks
- Take it easy, no intense exercise
- Can use electronic devices
- Use shield or glasses outdoors
- Bathe and shower as usual
- No driving until advised safe to do so
Cataract Surgery Complications
- Rupture of Posterior Lens Capsule
- Posterior dislocation of IOL
- Endophthalmitis
- Double Vision/Ptosis
- Increased IOP
- Corneal oedema
- CMO
- Dysphotopsia
- Posterior capsular opacification
Rupture of Posterior Lens Capsule
- Can be accompanied by vitreous loss, posterior migration of lens material and expulsive haemorrhage
- Vitreous loss can lead to:
- CMO
- Retinal detachment
- Endophthalmitis
Posterior Dislocation of IOL
- Rare
- IOL ends up in vitreous cavity
- Occurs in eyes with fragile zonular attachments e.g. in pseudoexfoliation where in entire capsular bag may dislocate
- Can lead to:
- Vitreous haemorrhage
- Chronic CMO
- Uveitis
- Retinal detachment
Endophthalmitis Risk Factors
- Posterior capsular rupture
- Prolongued procedure time
- Combined procedure
- Diabetes
How does Endophthalmitis Damage the Eyes?
- Acute intraocular infection
- Damage is done by toxins produced by infecting bacteria and inflammatory response
Endophthalmitis Treatment
- Intravitreal antibiotics
- Subconjunctival antibiotics injections
- Topical antibiotics
- Oral antibiotics
- Oral steroids
- Pars plana vitrectomy
Double Vision/Ptosis After Cataract Surgery
- Can occur post-operatively due to clamps used during surgery
- Can unmask existing phoria
- Usually self resolving
- Needs investigated to rule out unrelated neurological event
Increased IOP After Surgery
Causes:
- Steroid responder
- Leftover viscoelastic material
What is Viscoelastic?
- Facilitates surgery by ensuring spaces such as AC remain open throughout procedure
Cystoid Macular Oedema After Cataract Surgery
- Occurs 6 to 10 weeks after surgery but can take longer to appear
- Presents with symptoms of blurring especially at near along with possible distortion
Corneal Oedema After Cataract Surgery
- Can be caused by high-powered phaco used to break up a very dense cataract
- Treated with 0.1% dexamethasone or 1.0% prednisolone
Dysphotopsia After Cataract Surgery
- Positive dysphotopsia is flashing lights and floaters
- Negative dysphotopsia is dark scotomas
- Investigate as risk of retinal detachment
- Rounded edge IOL are less likely to cause negative photopsia
- Phenomena tends to reduce over time
Posterior Capsular Opacification After Cataract Surgery
- Proliferation of leftover lenticular cells which have remained within lens capsule
- Results in variable degree of reduced vision
- Square edge design though to be less susceptible
- Treatment is via YAG laser known on posterior capsulotomy
Dry AMD Advice
Smoking cessation
- Associated with earlier AMD onset
- Associated with faster progression
Dietary Advice
- Encourage intake of food with lutein and zeaxathin content such as kale, red pepper or leafy green veg
- Supplementation (careful in smokers)
UV Protection
- Can protect back of eye
Two Main Wet AMD Medical Interventions
- Anti-VEGF
- Photodynamic therapy
What do Anti-VEGF Medications do in Wet AMD?
- VEGF is a protein which allows for the formation of new blood vessels when produce by the body
- These vessels can damage vision via leakage
- Anti-VEGF therapy slows development of new vessels and helps maintain vision
- Injection itself takes on 20 seconds
Types of Anti-VEGF Therapy
Ranibizumab
- Lucentis injections given every 4 weeks for as long as necessary
Brolucizumab
- Beovu injections every 12 weeks
Photdynamic Therapy In Wet-AMD
- Verteporfin is light activated drug that is injected into arm and eventually enters circulation of vessels at the macula
- Ophthalmologist can use a laser focussed by a contact lens which activates drug and causes destruction of the abnormal vessels
- Multiple treatments are required
Features Suggestive of R3 DR
- 4 or more dot/blot haemorrhages
- IRMA
- Venous beading
General Points for Management of DR
Patient Education
- Emphasise need to comply with review and treatment schedules
- Attend DR screening
- Information on weight management
Diabetic Control
- Optimised control of diabetes
Other Risk Factors
- HBP and high cholesterol control
Other Factors
- Smoking stopped
- Renal failure issues addressed
- Anaemia addressed
Treatment of Diabetic Macular Oedema
- Intravitreal anti-VEGF Agents
- Focal/Grid Laser Photocoagulation
What is the Difference Between Focal/Grid Laser?
- Focal laser is applied directly to the cause of oedema
- Grid laser is applied to more general areas where there is leakage coming from IRMA or capillary beds
Intravitreal Anti-VEGF in DMO Treatment
Intravitreal anti-VEGF Agents
- Intravitreal ranibizumab improves VA more effectively than focal/grid laser for centre involved DMO
- Laser treatments should be deferred for 6 months after this point
- Good outcomes can be expected for around 5 years
Focal/Grid Laser Photocoagulation in DMO Treatment
- Laser burns applied directly to the causes of oedema
- Treats areas no closer than 500 microns from fovea
- Only indicated with non-centre involved DMO
Treatment of Proliferative Diabetic Retinopathy
- Scatter Laser Treatment (PRP)
- Intravitreal anti-VEGF
- Pars plana vitrectomy
Scatter Laser Treatment in Proliferative DR Treatment
- Mainstay of Proliferative DR Treatment (AKA pan retinal photocoagulation)
- Performed under topical anaesthesia
- Laser applied to peripheral retina which causes shrinkage of vessels and inhibits future growth
- Reduces risk of vitreous haemorrhage and retinal detachment
- Multiple treatments may be required
Intravitreal Anti-VEGF Agents in Proliferative DR Treatment
- Intravitreal ranibizumab is as effective as PRP in patients at risk of proliferative DR
- Macular oedema risk reduced when compared to PRP
- Peripheral vision better preserved compared to PRP
Pars Plana Vitrectomy in Proliferative DR Treatment
- For advanced DR
- Sometimes combined with PRP
- Indications include retinal detachment and vitreous haemorrhage
Types of Surgical Glaucoma Management
- Selective Laser Trabeculoplasty (SLT)
- Laser iridotomy
- Trabeculotomy
Selective Laser Trabeculoplasty in Glaucoma Management
- Now first line treatment according to SIGN
- Used in treatment of POAG
- Laser focussed onto trabecular meshwork which stimulates better drainage through a biological/chemical process
- Often results in 25% drop in pressure
- Around 80% of patients can expect to be drop free and at target pressure after 3 years
- Effects wane over time but surgery can be repeated again
- Complications include ocular inflammation
Selective Laser Trabeculoplasty vs Argon Laser Trabeculplasty
- Less intense complications compared to Argon Laser
- In Argon Laser there is also mechanical opening of trabecular meshwork which contributes to IOP lowering
Laser Iridotomy in Glaucoma Management
- Used in treatment of ACG
- Focussed laser beam is used to create and opening in iris to allow passage of trapped aqueous
- Complications include:
- Iritis
- Corneal burns
- Cataract formation
- Monocular diplopia when coincident with lid margin
Trabeculotomy
- Creation of a fistula which allows aqueous from AC into subtenant space protected by a flap created in the sclera
- Aqueous drains out and forms a blur which is hidden under upper lid, where it is absorbed into the blood stream
- Indicated in advanced glaucoma/young patient where low IOP targets are needed
- Complication can include infection of bleb leading to Endophthalmitis
Glaucoma Drops Order of Prescribing
1st Line: Prostaglandin Analogues
2nd Line: Beta Blocker/Carbonic Anhydrase Inhibitor/Alpha Agonist
3rd Line: As for 2nd but add from a different class
4th Line: As for 3rd but can also include pilocarpine in some cases
Prostaglandin Analogues Mechanism of Action
- Prostaglandins are pro-inflammatory molecules
- They act at F2 receptors in the ciliary muscle and increase outflow by inducing ciliary muscle relaxation
Prostaglandin Analogues Effectiveness
- Several weeks from starting treatment until maximum effect is enjoyed
- Can expect a 25-35% decreased in IOP
- Initial effect after 2 hours
- Peak effect after 8 to 12 hours
- Duration of effect for 24 hrs
Prostaglandin Analogues Examples
- Latanoprost (od)
- Travoprost (od)
- Bimatoprost (od)
- Tafluprost (od)
Prostaglandin Analogues Contraindications
- Uveitis
- CMO
- HSK
- Aphakia and pceudoaphakia (risk of CMO)
- Pregnancy (effect on uterus)
Prostaglandin Analogues Side Effects
- Conjunctival hyperaemia
- Punctate keratopathy/FB sensation/ocular irritation
- Increased iris/lower lid pigmentation
- Lengthening of lashes
- CMO/Uveitis/HSK
Carbonic Anhydrase Inihibitors Mechanism
- Lower IOP via inhibiting the enzyme carbonic anhydrase found in ciliary body epithelium which reduces aqueous production
- Potential protective effect on optic nerve head
Carbonic Anhydrase Inihibitors Examples
- Dorzolamide (bd/tds)
- Brinzolamide (bd)
- Drops are in suspesion form so need shaking prior to use
Carbonic Anhydrase Inihibitors Effect
- Around 20% reduction
Carbonic Anhydrase Inihibitors Side Effects
- Hyperaemia
- Ocular irritation/FB sensation/ocular pain
- Transient blurred vision
- Corneal thickening and clouding in unhealthy endotheliums
- Aplastic anaemia or Stevens-Johnsons Syndrome (rare in topical use)
Beta Blockers Mechanism
- Reduce aqueous production by reducing ultrafiltration, which is one of three methods of by which aqueous is produced
Beta Blockers Effect
- Around 20 - 30% reduction in IOP
- Suffer from tachyphylaxis
- No effect difference in concentration
Beta Blockers Examples
- Timolol
- Betaxolol
Beta Blockers Side Effects
Ocular side effects of Beta Blockers include:
- Corneal hypaesthesia
- Punctate keratopathy/dry eye/burning/stinging
- Pseudopemphigoid
Systemic side effects of Beta Blockers include:
- Anxiety
- GI disturbances
- Reynauds
- Arrhythmia
- Systemic hypotension
- Exacerbation of asthma
Beta Blockers Cautions
- Patients with arrhythmias/cardiac failure/COPD
- Patients on systemic beta blockers
- Elderly patients
Alpha-2 Agonists Mechanism
- Reduces aqueous by acting on alpha-2 receptors which inhibit enzymes involved in aqueous production
Alpha-2 Agonists Effect
- Around 20 - 25% reduction
- Usually additive with other agents, not at effective as monotherapy
- Apraclinidine suffers from tachyphylaxis
Alpha-2 Agonists Examples
- Apraclonidine
- Brimonidone
Alpha-2 Agonists Side Effects
- High rate of ocular allergy (hyperaemia and follicular conjunctivitis)
- Dry mouth
- Drowsiness
- Systemic blood pressure reduction
Alpha-2 Agonists Contraindications
- Patients taking MAOIs or tricyclic antidepressants
- Severe cardiac disease
Acute Allergic Conjunctivitis Management
- Avoidance of allergen
- Avoidance of eye rubbing
- Cold compresses for symptomatic relief
- Prophylactic sodium cromoglicate 2% qds
- Olopatidine bds whilst symptomatic
Seasonal Allergic Conjunctivitis Management
- Advise recurrent nature
- Avoidance of eye rubbing
- Cold compresses for symptomatic relief
- Sodium cromoglicate 2% qds prophylactically
- Olopatidine bds for immediate relief
- Oral antihistamine
Bacterial Conjunctivitis Management
- Typically self resolving within a week
- Bathing and cleaning of lid margins with purpose made wipes or cooled boiled water and cotton wool
- Remove CLs
- Advice on contagious nature
- Supply chloramphenicol 1% ointment ads for 1 week
- Refer if: corneal involvement or non-resolving
MGD Management
- Advise there isn’t a “cure”
- Heat up blockage and massage it out, then remove
Anterior Bleph Management
- Advise isn’t a “cure”, likely to flare up
- Lid hygiene measures still effective
- Treat associated dry eye with lubricants
- Chloramphenicol 1% ointment ads for 1 week to reduce bacterial load
- BlephEx
- If associated with rosacea then refer to IP colleague for systemic tetracycline use
Dry Eye Management
Advice
- Give up smoking/avoid smoky enviroments
- Avoid windy environments
- Heated environments
- Air con
- VDU usage
- Medication as a cause
- Artificial tears
- Unmedicated ointment at nightime
- Acetylcystine 5% for mucus strands
