• Chronic glaucoma..when to laser
• Ultrasound appearance
• how to laser PIs
• topiramate

The normal lens/axial length ratio =15%. Such eyes rarely develop acute glaucoma or need laser

If the lens/axial length ratio >20%, and gonioscopy shows narrow angles, there may be a risk and such a patient may need laser. Such advice will change according to more definitive studies such as the ultrasound studies immediately above. An axial length measurement (A scan) will give these figures.

Check history, family history, refraction (high myper-mertopia contributes).

Cupping suspect. Angle needs to be narrower than 25% grade 1 (narrow), check gonio with eye movements and indentation.

• Axial length <22mm.
• Anterior chamber depth < 2.2mm.
• Lens thickness >4.0mm.
• Lens thickness/axial length ratio LT/AL > 20% is very suspect.
• if there is pigment in the superior angle
• earlier if there is a family history of angle closure
• earlier if there is diabetes require dilating
• patient choice if clinically borderline
• use the Van Herrick test and look at the peripheral angle
• the pressure rise may be due to pupil block, aqueous mis-direction, or ITC  (irido-trabeular contact),
  

• pre-laser ..pilocarpine 2-4%; 1% apraclonidine; dexamethasone minims
• apraconidine reduced iris blood flow and helps laser penetration at lower power.
• laser 11-1 o'clock
• try to avoid lasering where not covered with eyelid...also avoid superior lid tear film miniscus
• if laser is not under the eyelid...patients will get ghosting or glare
• stop aspirin, gingo a few days before..as these increase risk of bleeding
• warfarin...ideally this would be stopped...but as it is often important to prevent emboli, proceed with care (but check not over-anticoagulated)
• both eyes separately (this is controversial, many others carry out both eyes same session)
• laser day after acute attack or earlier if corneal clear...
• immediate paracentesis in acute glaucoma may abort attack...follow this with laser PI, cataract surgery, etc
• post-laser inflamaton is related to iris pigmentation

if there is advanced glaucoma

• expect a pressure rise
• add oral diamox
• take pressure 1 hour afer

where uveitis present/expected

• consider adding froben

during laser

• iris should go flatter...assess 1 hour later
• hard if corneal arcus present
• if cannot get through..consider surgical PI
• Afrocaribean..higher power...eg 9mx 2 pulses (versus normal power 6 x 2mj)
• setting...2 pulses, about 6 mj, use an iridotomy contact lens
• when lasering . iridotomy are patent when there is a rush of aqueous and pigment...
• if you think you are through but are not sure proceed with 1 or 2 extra shots until a GOOD PLUME OF AQUEOUS seen
• typically 2-4 shots will get through with this good plume of aqueous

if patient does get too much glare

• often this could have been prevented by lasering under the eyelid
• polarised lenses will reduce glare considerably

following laser

• dexamethasone 2 hourly drops for 2 weeks
• extra diamox if disc is cupped or pressure rise expected, perhaps froben if uveitis present
• review 1-2 weeks

This is a new treatment for severe epilepsy and migraine. Unfortunately it may cause angle closure glaucoma, see. Treatment is DIFFERENT FROM  ordinary ACUTE GLAUCOMA .

• paper    article
• treatment with
  • cyclopentolate, dilate pupil, steroids, probably NO diamox
  • try and detect suprachoroidal fluid (ultrasound or OCT) and myopia
  • NO MIOTICS
  • this treatment works over 2-3 days..some alternative treatment is needed.