Primary angle closure glaucoma (PACG) results from occlusion of the trabecular meshwork by the peripheral iris, obstructing aqueous outflow. It has several classifications including primary angle closure suspect (PACS), primary angle closure (PAC), and PACG. PACG is usually caused by pupillary block but can also be caused by non-pupillary block mechanisms. Risk factors include older age, female sex, Asian ethnicity, hyperopia, and shallow anterior chamber. Treatment involves laser iridotomy, medical therapy, and sometimes surgery.

1. PRIMARY ANGLE
CLOSURE
GLAUCOMA
MAJ F M ASHEKULLAH
FCPS PART-11 TRAINEE IN
OPHTHALMOLOGY

2.  The term ‘angle closure’ refers to
occlusion of the trabecular meshwork
by the peripheral iris (iridotrabecular
contact – ITC), obstructing aqueous
outflow. PACG may be responsible for
up to half of all cases of glaucoma
globally

3. Classification
• Primary angle closure Suspect( PAC-Suspe
• Primary angle Closure (PAC)
• Primary Angle-Closure Glaucoma(PACG)

4. Primary angle closure suspect
(PACS)
○ Gonioscopy shows posterior
meshwork ITC in three or more
quadrants but no PAS.
○ Normal IOP, optic disc and visual
field.
- The risk of PACG at 5 years may be
around 30%.

6. Primary angle closure
(PAC)
○ Gonioscopy shows three or more
quadrants of ITC with raised IOP
and/or PAS or excessive pigment
smudging on the TM.
○ Normal optic disc and field.

8. Primary angle-closure
glaucoma (PACG)
○ ITC in three or more quadrants, with
glaucomatous optic neuropathy.
○ Optic nerve damage may not appear
as typical glaucomatous cupping.

9. Mechanism
Relative pupillary block
○ Failure of physiological aqueous flow through
the pupil
leads to a pressure differential between the
anterior and posterior chambers
anterior bowing of the iris .
○ The lens vault quantifies the portion of the
lens located anterior to the anterior chamber
angle

11. Non-pupillary block
○ Far Eastern patients.
○ deeper anterior chamber (AC) than pure
pupillary block.
○ younger than those with pure pupillary
block.
○ angle closure is not fully relieved by
iridotomy.
○ plateau iris, and a thicker or more

12. ○ Plateau iris configuration is
characterized by a flat or only slightly
convex central iris plane. A
characteristic ‘double hump’ sign is
seen on indentation gonioscopy.
○ Plateau iris syndrome describes the
persistence of gonioscopic angle
closure despite a patent iridotomy in a
patient with morphological plateau iris

14. • Reduced aqueous outflow in angle
closure caused by the following
mechanisms :
○ Appositional obstruction by the iris.
○ Degeneration or damage of the TM
itself
○ Permanent occlusion of the TM by
PAS

15. Risk factors
• Age
• Family history
• Gender. Females >males.
• Axial length
• Race.Far Eastern and Indian Asians
• Refraction.Up to one in six patients with
hypermetropia of one dioptre or more are
primary angle closure suspects
- so routine gonioscopy should be
considered in all hypermetropes.

17. Diagnosis
Symptoms
• Most are asymptomatic.
• intermittent mild symptoms of blurring
(‘smoke-filled room’) and haloes
(‘rainbow around lights’) or acutely
with markedly decreased vision,
redness and ocular/periocular pain
and headache etc.

18. • Precipitating factors include
- watching television in a darkened
room,
- pharmacological mydriasis
- semiprone position (e.g. reading)
- acute emotional stress and
-occasionally systemic medication

19. Signs
• Chronic presentation
○ VA is normal unless damage is
advanced.
○ The AC is usually shallower in relative
pupillary block than non-pupillary block.
○ IOP elevation may be only intermittent.
○ ‘Creeping’ angle closure
○ Intermittent ITC with discrete PAS
○ Optic nerve signs

20. • Acute primary angle closure (APAC)
- VA is usually 6/60 to HM.
- The IOP is usually very high (50–100
mmHg).
- Conjunctival hyperaemia with violaceous
circumcorneal injection.
- Corneal epithelial oedema
-The AC is shallow, and aqueous flare is
usually present.
- An unreactive mid-dilated vertically oval
pupil

21. • Resolved APAC
○ Early:
-low IOP
-folds in Descemet membrane
- optic nerve head congestion
-choroidal folds.

22. ○ Late:
-iris atrophy with a spiral-like
configuration
-glaukomflecken and other forms of
cataract
-irregular pupil due to iris
sphincter/dilator damage
-posterior synechiae
- optic nerve may be normal or exhibit
pallor and/or cupping

23. ○ The greater
(i) the duration of an attack of APAC
and
(ii) the extent of post-APAC PAS
the lower the likelihood of IOP control
with medical treatment alone.

26. Investigation
• Anterior segment OCT
• Anterior chamber depth measurement
• Biometry if lens extraction is
considered.
• Posterior segment ultrasonography
• Provocative testing.
○ Pharmacological mydriasis
○ Dark room/prone provocative test
(DRPPT):

27. Differential diagnosis of acute
IOP elevation
• Lens-induced angle closur
• Malignant glaucoma
• Neovascular glaucoma
• Hypertensive uveitis
• Scleritis (rarely episcleritis)
• Pigment dispersion.
• Pseudoexfoliation.
• Orbital/retro-orbital lesions

28. Treatment
PACS
• Laser iridotomy
• If significant ITC persists after iridotomy,
options include observation (most), laser
iridoplasty, and long-term pilocarpine
prophylaxis, If symptomatic cataract is
present, lens extraction
PAC and PACG
• Management is as for PACS
• Medical treatment as for POAG may be

30. APAC
• Initial treatment
○ supine position
○ Acetazolamide 500 mg intravenously if IOP >50
mmHg, and orally if IOP is <50 mmHg.
○ If treatment is intravenous an additional oral dose of
acetazolamide 500 mg
○ A single dose of each of apraclonidine 0.5% or 1%,
timolol 0.5%, and prednisolone 1% or dexamethasone
0.1%
○ Pilocarpine 2–4% one drop to the affected eye,
repeated after half an hour; one drop of 1% into the
fellow eye

31. • Resistant cases
○ Central corneal indentation
○ Further pilocarpine 2–4%, timolol 0.5%,
apraclonidine 1% and topical steroid.
○ Mannitol 20% 1–2 g/kg intravenously over 1
hour
○ Early laser iridotomy or iridoplasty
○ Paracentesis can be performed
○ Surgical options: peripheral iridectomy, lens
extraction, goniosynechialysis,
trabeculectomy and cyclodiode.

32. Globe Compression

33. Peripheral Iridectomy

34. • Subsequent medical treatment
○ Pilocarpine 2% four times daily to the
affected eye and 1% four times daily to
the fellow eye.
○ Topical steroid four times daily
○ Any or all of the following should be
continued as necessary according to
response: timolol 0.5% twice daily,
apraclonidine 1% three times daily and
oral acetazolamide 250 mg four times
daily.

35. • Bilateral laser iridotomy is performed
once an attack has been broken.
• Trabeculectomy is occasionally
necessary.

36. Follow up
 Repeat gonioscopy to look for chronic
angle closure.

37. reference
1.Kanski’s clinical ophthalmology
2.American academy section 10
3.Parson’s diseases of the eye
4.Wilis eye manual