• slit lamp technique in glaucoma
• chronic glaucoma..when to laser
• gonoiscopy appearance
• grading gonioscopy appearance...does the patient
  need a PI
• documenting gonioscopy appearance
  
  
• management principles
• other slit lamp signs
• Ultrasound appearance
• how to laser PIs (peripheral iridotomies)
• how to laser a thick iris
  
  
• glare after PIs
• topiramate and other drugs
• Uveal Effusion in Asian Eyes With Primary Angle Closure Glaucoma
• genes
• risk factors
  
  
• symptoms
• iridoplasty and plateau iris
• www.gonioscopy.org...a wonderful website
• helpful book
• cataract
  

• What is glaucoma?
  • Text
  • Animation of glaucoma
  • Professionals: notes
  • SLT laser
  • high myopia and glaucoma
• Angle closure glaucoma & narrow angle glaucoma / laser iridotomies
  • Animation of laser iridotomy
  • Chronic narrow angle glaucoma
  • Text
  • Professionals: notes
• Internat. Glaucoma Association
• Intraocular hypertension
• Low tension glaucoma
• Pre-perimetric glaucoma
• Visual field testing
• Drops & tablets for glaucoma
• Animations etc
  • Glaucoma
  • Laser iridotomy
  • Trabeculectomy
  • Rubeotic glaucoma
  • Progression model
  • SLT laser
• Rubeotic glaucoma
  • Text
  • Rubeotic glaucoma animation
  • Professionals: notes
• Students: Cases
  • Case 1
  • Case 2
  • Case 3
  • Case 4
  • Case 5
  • Case 6
  • Case 5
  • Case 8
  • Case 9
  • Case 10
  • Case 11
• Pseudoexfoliation..link
• Pigmentary glaucoma ..link
• Trabeculectomy
  • Text
  • Animation
  • Audit
    • 2006 with photos
    • 2008
• More technical
  • Corneal thickness & IOP
  • Hypotony
  • Arcuate scotomas ..glaucoma?
• Glaucoma letters
• Glaucoma photos (professionals)

By using the same examination technique each time, you are less likely to forget what to look for. An idea (Prof Peter Shah)

1. start
2. look for stromal atrophy
3. glaucomaflecken/central depth
4. corneal oedema
5. Van Herrick test (diagram)
6. convex iris configuration

The normal lens/axial length ratio =15%. Such eyes rarely develop acute glaucoma or need laser PIs.
If the lens/axial length ratio >20%, and gonioscopy shows narrow angles, there may be a risk and such a patient may need laser. An axial length measurement (A scan) will give these figures.
Check history, family history, refraction (high hypermetropia contributes).

• 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   (diagram) and look at the peripheral angle
• the pressure rise may be due to pupil block, aqueous mis-direction, or ITC  (irido-trabeular contact)
• measure the horizontal corneal diameter with a plastic ruler
  • average 12mm
  • megacornea 13mm
  • microcornea <11mm
• suspect angle closure attacks with iris atrophy, pigmentation on trabecular meshwork,
• always carry our gonioscopy in the DARK as the angle will be narrower.

Use the view below to identify Schwalbe's line.

• very dim room illumination
• slit lamp angle at 10 degrees...the first notch
• very narrow beam
• short beam....angle opens if pupil goes small (if light goes in pupil)
• look for the inverted 'Y' pattern as below...Schwalbe's line is at the join
• don't press, assess in primary position, don't tilt to start
• helpful book

Angle becomes narrower over the years in some people

1. anda...anatomically narrow drainage angle
   (ANDA: can see pigmented trabecular meshwork all round, safe)
   2 years later progresses in 33%
   
   
2. ITC: iridotrabecular contact: cannot see pigmented angle in places
   2 years later progresses in 33%
   
   
3. PAS...peripheral anterior synechiae
   2 years later...
   
   
4. PAC: primary angle closure= ITC + IOP (high pressure) + PAS + symptoms

ANDA...patient can be discharged
ITC  <180 degrees, no need to watch carefully (yearly exam at optometrist)
ITC  >180 degrees, generally needs a PI
PAC/PACG needs PI
Concerning when to carry out laser PI: make decisions in pirmary position without indentation

Abbreviations, for example (in the direction of the mirror..12 o'clock on the drawing is 12 o'clock in the patient's eye)

1. ITC: iridotrabecular contact
2. llNP  ....see non-pigmented trabecular meshwork only
3. llP  ....see pigmented trabecular meshwork
4. PAS

• Once the ITC (iridotrabecular contact) exceeds 180 degrees, surgery is indicated (laser iridotomies [PIs] or lens removal [phaco or 'cataract surgery'].)
• If, despite the PIs, the ITC (iridotrabecular contact) exceeds 180 degrees, the laser iridoplasty as below may be needed.
• If, despite the PIs & iridoplasty, the ITC (iridotrabecular contact) exceeds 180 degrees, phaco may be needed.
• If the ITC reduces to, 180 degrees, the pressure
  • may be normal, and regular checks over years are needed until it is clear the angle is not starring to close again
  • the pressure may be slightly high, and Xalatan drops or equivalent may control the pressure
• If the pressure remains high, trabeculectomies will be needed. Usually phaco is carried out first.
• If the angle closure is secondary to another condition (eg inflamation) and recent, gonioviscolysis may help, possibly with iridectomy.
• patients with narrow angles develop PAS and high IOP at a rate of ~20%/year, as in this diagram below:
  

• anterior chamber depth, centrally
• anterior chamber depth, peripherally (Van Herrick's test)
• stromal atrophy
• glaucomaflecken
• convex iris configuration

See this page   Also see

• pre-laser ..pilocarpine 2%; this makes iris more taught.
• 1% apraclonidine; dexamethasone minims
• apraclonidine (iopidine 1%) reduces iris blood flow and helps laser penetration at lower power: use 1 hour before and again at time of laser Yag laser
• laser 11-1 o'clock
• 12 o'clock may be obstructed with bubbles...best 11.30 or 12.30 position.
• try to avoid lasering where not covered with eyelid...also avoid upper lid tear film meniscus
• if laser is not under the eyelid...patients will get ghosting or glare
• similarly lasering under the upper lid meniscus makes visual symptoms of polyopia etc more likely ...these can be very troublesome.
• stop aspirin and gingo a few days before..as these increase risk of bleeding (gingo biloba...leave a 10 day gap without)
• 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, I personally carry out both eyes if low risk in same session)
• post-laser inflammation is related to iris pigmentation

acute attack

• 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

PI if there is advanced glaucoma

• expect a pressure rise
• add oral diamox for several days
• take pressure 1 hour after

where uveitis present/expected

• consider adding froben

during laser

• iris should go flatter...assess 1 hour later
• procedure is more problematic if there is a corneal arcus
• if cannot get through..consider surgical PI
• Afro-Caribbeans ..higher power...eg 9mx 2 pulses (versus normal power 6 x 2mj)
• Yag laser setting...1 pulses, about 6 mj, use an iridotomy contact lens eg Wise 55 dioptre lens
• when lasering . iridotomy is patent when there is a rush of aqueous and pigment, like a mushroom of 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

following laser

• dexamethasone (such as Maxidex) 2 hourly drops for 4 days reducing to 4 times a day for 2 weeks post-laser (if lots of inflammation expected, start hourly for a day, then reduce.
• extra diamox if disc is cupped or pressure rise expected, perhaps froben if uveitis present
• review 1-2 weeks, always repeat goinioscopy to check angle has opened. If not consider plateau iris.

Usually Yag laser above works. Occasionally the iris is so thick surgery is needed (very unusual in the UK). However, some irisis are very thick, but can be lasered by carrying out argon laser first.

• see
• before the YAG laser
• using the PI lens (usually a 'Wise' lens)
• using 200µ 0.1 second light burns applied to the surface of the iris (clearly visible...adjust the power so there is a visible burn)
• apply a ring of argon laser
• then change to the Yag laser and laser in the usual way.
• effectively the argon laser stretches the iris making iteasier for the Yag laser to perforate.
• this technique works for most thick irisis if the Yag laser itself does not work straight away.

 a ring or argon laser (red) is carried out before the Yag (white)

• often this could have been prevented by lasering under the eyelid
• polarised lenses will reduce glare considerably
• corneal tattoo may help.

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 .

• 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..if not, some alternative treatment is needed.
• Sympathomimetics, anticholinergics (such as tricyclic antidepressants), anthistamines, and idiosyncratic (such as Topiramate). Stress, the head down posture, low lighting, extreme climates, may precipitate attacks.
• Older patients, women will get more attacks. Also, Asian women may be more prone.

See   90% in Chinese families

See Casson 2009

• shorter AL
• shorter ACDs
• thicker lenses than those without occludable angles.
• thicker iris BJO 2010
• In multivariate analysis, increasing age, decreasing AL, decreasing ACD, and nuclear cataract were significant predictors of early AD. The presence of nuclear cataract per se should raise clinical suspicion of the possibility of AD in this population.

• haloes/pain/intermittent/unilateral/relationship to tasks such as reading
• when you get the haloes, are the eyes red?
• how does the eye feel when it is red? (an ache suggests higher pressure/inflammation)

• see plateau iris    
• use for plateau iris only, not simply angle closure
  • Argon laser
  • Abraham lens
  • 0.2 seconds
  • 200µ
  • 400mj
  • 2 quadrants
  • 10 applicatons/quadrant
  • Lim 93

This is becoming increasingly noticeable as anterior segment imaging (OCT or ultrasound) becomes available.

A plateau iris may cause angle obstruction (and rise in pressure), particularly in ther dark. This is a diagam of the OCT appearance.

Hoffer Q or Hargis formulae for very small eyes (2010)