Adult onset optic neuropathy with open angles

1% of the population but up to 50% may be undiagnosed

## Risk factors
- Age
- Ethnicity: Afro-caribbean
- Family history
- Steroid induced IOP elevation (“steroid responder”)
- Vascular disease (diabetes, HTN)
- Myopia: possibly due to scleral canal morphology
- Genetics: **GLC1A** (**TIGR/MYOC**) was the first POAG gene discovered on chromosome 1
    - Encodes **myocilin**, a protein that can be induced in the TM by topical steroid
    - Found in 3% of adults with POAG
    - Even more so associated with juvenile onset glaucoma

## Clinical features
- Typically asymptomatic
- IOP >21 with higher than usual diurnal variability
- C:D asymmetry
- High C:D for disc size
- Vertical elongation of the cup
- NRR notch/thinning out-of-keeping with ISNT rule
- Disc haemorrhage
- Vessel bayoneting
- Nasally displaced vessels
- Peripapillary atrophy: “beta” zone PPA is directly adjacent to disc
- Visual field defects: focal defects respecting the horizontal meridian
    - Nasal step
    - Baring of blind spot
    - Paracentral scotomas
    - Arcuate defects
    - Altitudinal defects
    - Generalized depression of the field

## Management
- Counselling including implications for driving and importance of drop compliance
- Define target IOP: typically at least a **20% reduction** at first. Aim for &lt;18 in moderate and &lt;15 in advanced disease
- Review initial treatment at 6 weeks
- Topical therapy
    - Prostaglandin analogues
    - Beta blockers
    - Alpha2 agonists
    - Carbonic anhydrase inhibitors

- Laser trabeculoplasty: argon (ALT) or selective (SLT)
    - IOP control may fall with time (50% failure at 5 years)

- Trabeculectomy +/- augmentation
    - Occasionally a primary treatment in advanced disease with a need for low target IOP especially if intolerant of topical therapy
    - Mitomycin C is anti-scarring

- Shunt procedures: Baerveldt, Molteno or Ahmed tubes
- Ciliary body destruction: diode laser cycloablation

### NICE guidelines for chronic open angle glaucoma (COAG)

<HotTopic>The NICE guidelines for glaucoma management are a hot topic in exams, including in evidence-based medicine stations in the Oral exam!</HotTopic>

- Do not offer treatment if IOP &lt;24 and patient is not at risk of visual impairment in their lifetime
- Initial treatment: offer 360 degree selective laser trabeculoplasty (SLT) unless pigment dispersion syndrome
    - SLT can delay need for eye drops
    - SLT can be offered to patients with OHT if IOP is >24 and they are at risk for visual impairment within their lifetime

- Generic prostaglandin analogue if:
    - Patient does not wish SLT
    - SLT not suitable (eg. pigment dispersion syndrome)
    - Patient requires interim treatment prior to SLT
    - IOP not sufficiently lowered by SLT

- If ongoing progression: check adherence with drops and instillation technique
- If satisfactory adherence/technique:
    - Add further topical treatment with another drug class
    - Offer 360 degree SLT if not previously tried
    - Consider glaucoma surgery with augmentation

- Always consider SLT or surgery if unsatisfactory control with 2 or more topical agents
- If a topical therapy cannot be tolerated, consider an alternative drug agent or a preservative free preparation
- Patients who present with advanced COAG can be offered glaucoma surgery with augmentation directly, with topical therapy as an interim measure
- Follow-up times are based on the IOP control, perceived risk of conversion to COAG (for OHT patients) or risk of sight loss


Glaucoma

Primary Open Angle Glaucoma

Intro

FRCOphth Part 2 Study Notes

Tumours, masses and neoplasia

Tumours overview

Uveitis

Uveitis background

Anterior uveitis

Intermediate uveitis

Uveitis in JIA

Uveitis with JIA

Retinal vasculitis

Sarcoidosis

Behcet's disease

Toxoplasmosis

Strabismus

Overview

Viral uveitis

Esotropia

Fungal uveitis

Mycobacterial uveitis

Adnexal masses

Exotropia

Spirochaetal uveitis (including Syphilis)

Melanoma

Nematode uveitis

Retinoblastoma

Retinoblastoma (for Part 2)

Incomitent

Voyt-Koyanagi-Harada syndrome

Conjunctival intraepithelial neoplasia

Vertical deviations

Orbit and ocular adnexae

Orbit

Sympathetic ophthalmia

AV Malformations and hamartomas

Arteriovenous malformations and hamartomas

Restriction syndromes

Paediatrics

Leucocoria

Congenital Cataract

Paediatric Glaucoma

Retinopathy of prematurity

Retinopathy of Prematurity

ROP-like disorders

Congenital nasolacrimal duct obstruction

White dot syndromes

Aniridia: Short Arm 11 Deletion (11p13)

Choristomas

Management Of Amblyopia

Alphabet patterns

Iris Nodules

Scleritis

Meningioma

Strabismus surgery

Optic nerve glioma

Lymphoma

Extraocular Muscles

Rhabdomyosarcoma

Idiopathic orbital inflammation

Orbital neuroblastoma

Anterior Persistent Foetal Vasculature

Lacrimal system

Metastatic lesions

Surgical Retina

Retinal Detachment

Vitreoretinal Interface And Macular Hole

Epiretinal Membrane

Medical Retina

Diabetic Eye Disease

Orbital Blood Vessels

Retinal Vascular Disease

Macular Degeneration

Central Serous Chorioretinopathy (CSCR)

Sickle Cell Retinopathy

Retinitis Pigmentosa

Albinism

Retinal Telangiectasias

Miscellaneous Retinopathies

Atropine And Myopia Progression

Pharmacology

Side Effects Of Systemic Drugs

Foetal Alcohol Syndrome

Neuro-ophthalmology

Optic Neuropathy

Papilloedema

Idiopathic Intracranial Hypertension

Chiasmal Disorders

Retrochiasmal Disorders

Migraine

Paranasal Sinuses

Supranuclear Motility Disorders

Third Nerve Palsies

Fourth Nerve Palsies

Sixth Nerve Palsies

Seventh Nerve Palsies

Anisocoria

Myasthenia Gravis

Myopathies

Blepharospasm

Functional Visual Loss

Lacrimal Glands

Phakomatoses

Developmental diseases

Tear Film

Eyelids

Blinking

Lid Malpositions

Anterior segment - ocular surface

Conjunctiva

Conjunctivitis

Sclera

Pigmented Conjunctival Lesions

Squamous Cell Carcinoma Of The Conjunctiva

Ocular Cicatricial Pemphigoid

Cornea

Corneal Structure And Development