Adult Medical-Surgical Adult Medical-Surgical Nursing Nursing

Neurology Module: Neurology Module:

GlaucomaGlaucoma

Glaucoma: DescriptionGlaucoma: Description

A condition where congestion of the A condition where congestion of the aqueous humour of the eye leads to aqueous humour of the eye leads to increased intra-ocular pressure and increased intra-ocular pressure and damage to the optic nerve damage to the optic nerve May be:May be:Pernicious chronic Pernicious chronic AcuteAcuteA leading cause of visual impairment and A leading cause of visual impairment and irreversible blindnessirreversible blindness

Glaucoma: Aetiology/ Risk FactorsGlaucoma: Aetiology/ Risk Factors

Family historyFamily historyAfrican/ Asian race more at riskAfrican/ Asian race more at riskOlder ageOlder ageDiabetes MellitusDiabetes MellitusCardiovascular diseaseCardiovascular diseasePatients with migrainePatients with migraineMyopia, trauma, prolonged use of topical Myopia, trauma, prolonged use of topical or systemic corticosteroids or systemic corticosteroids

Aqueous Humour and Aqueous Humour and Intraocular PressureIntraocular Pressure

Aqueous humour flows between the iris Aqueous humour flows between the iris and lens nourishing the cornea and lensand lens nourishing the cornea and lens90% drains via trabecular meshwork into 90% drains via trabecular meshwork into the canal of Schlemm and episcleral veinsthe canal of Schlemm and episcleral veins10% drains into venous circulation of the 10% drains into venous circulation of the ciliary body, choroid and scleraciliary body, choroid and scleraAqueous humour production and drainage Aqueous humour production and drainage maintain intra-ocular pressure (IOP) maintain intra-ocular pressure (IOP) between 10 and 21 mm Hgbetween 10 and 21 mm Hg

Glaucoma: Glaucoma: Raised Intraocular Pressure Raised Intraocular Pressure

Unimpeded drainage depends on an open Unimpeded drainage depends on an open angle (45%) between the iris and corneaangle (45%) between the iris and cornea

Reduction of this angle leads to build up of Reduction of this angle leads to build up of intra-ocular pressure → glaucoma causing intra-ocular pressure → glaucoma causing damage to retina and optic nerve damage to retina and optic nerve

Glaucoma: ClassificationGlaucoma: Classification

Chronic open-angle glaucoma (COAG)Chronic open-angle glaucoma (COAG)

Acute angle-closure (pupillary block) Acute angle-closure (pupillary block) glaucomaglaucoma

Chronic Glaucoma (COAG)Chronic Glaucoma (COAG)

Chronic Glaucoma: Chronic Glaucoma: PathophysiologyPathophysiology

Usually bilateral Usually bilateral

Structural changes in aqueous outflow Structural changes in aqueous outflow (narrowed but open angle) →(narrowed but open angle) →

SilentSilent gradualgradual chronicchronic increase in IOP or increase in IOP or impaired bloodflow →impaired bloodflow →

Optic nerve damage and visual loss:Optic nerve damage and visual loss:

Direct pressure damage or indirect Direct pressure damage or indirect ischaemic compression of microcirculation ischaemic compression of microcirculation

Chronic Glaucoma: Chronic Glaucoma: Clinical ManifestationsClinical Manifestations

Gradual onset affecting both eyes. Patient Gradual onset affecting both eyes. Patient may be unaware until visual impairment may be unaware until visual impairment Blurred visionBlurred vision““Halo” around lightsHalo” around lightsDifficulty with focusDifficulty with focusDifficulty adjusting to low lightingDifficulty adjusting to low lightingLoss of peripheral vision → “tunnel vision”Loss of peripheral vision → “tunnel vision”Aching/ discomfort in eyes. Aching/ discomfort in eyes. HeadacheHeadache

Chronic Glaucoma: DiagnosisChronic Glaucoma: Diagnosis

Patient historyPatient historyTonometry (measurement of IOP)Tonometry (measurement of IOP)Ophthalmoscopy to inspect retina and Ophthalmoscopy to inspect retina and optic nerve : pallor (↓ blood supply) and optic nerve : pallor (↓ blood supply) and cupping (bending of vessels) diagnosticcupping (bending of vessels) diagnosticGonioscopy: (slit-lamp) measuring filtration Gonioscopy: (slit-lamp) measuring filtration angle of anterior chamber angle of anterior chamber Perimetry to assess visual fields (localised Perimetry to assess visual fields (localised areas of loss “scotomas”)areas of loss “scotomas”)

Chronic Glaucoma: ManagementChronic Glaucoma: Management

MedicalMedical

Laser surgeryLaser surgery

SurgerySurgery

Chronic Glaucoma:Chronic Glaucoma:Medical ManagementMedical Management

Aim to control IOP and prevent further Aim to control IOP and prevent further optic nerve damageoptic nerve damage

Topical (eye drops) and maybe systemic Topical (eye drops) and maybe systemic medications to lower IOPmedications to lower IOP

Miotic drops: constrict pupil allowing a Miotic drops: constrict pupil allowing a wider outflow of aqueous humourwider outflow of aqueous humour

ββ-blockers and adrenergic agonists: -blockers and adrenergic agonists: reduce aqueous production primarilyreduce aqueous production primarily

Chronic Glaucoma:Chronic Glaucoma:Laser Treatment and SurgeryLaser Treatment and Surgery

Laser surgeryLaser surgery (trabeculoplasty): (trabeculoplasty):Burns part of the trabecular meshworkBurns part of the trabecular meshworkWidens the canal of Schlemm increasing Widens the canal of Schlemm increasing outflowoutflowSurgerySurgery (trabeculectomy): removal of part (trabeculectomy): removal of part of trabecular meshwork creating a fistula of trabecular meshwork creating a fistula for drainage from anterior chamber into for drainage from anterior chamber into sub-conjunctival space (implanted sub-conjunctival space (implanted drainage shunt may be used) drainage shunt may be used)

Acute Angle-Closure (Pupillary Block) Acute Angle-Closure (Pupillary Block) GlaucomaGlaucoma

Acute Glaucoma: PathophysiologyAcute Glaucoma: Pathophysiology

Forward shift of peripheral iris towards Forward shift of peripheral iris towards trabeculatrabecula

Causes complete or partial closure of the Causes complete or partial closure of the angle →angle →

Obstruction of outflow of aqueous humour Obstruction of outflow of aqueous humour

Abrupt rise of intra-ocular pressure (IOP)Abrupt rise of intra-ocular pressure (IOP)

Acute Glaucoma: Acute Glaucoma: Clinical ManifestationsClinical Manifestations

Acute onset: ocular emergencyAcute onset: ocular emergencySevere peri-ocular pain one eyeSevere peri-ocular pain one eyeConjunctival hyperaemia and congestionConjunctival hyperaemia and congestionNausea, vomiting, bradycardia, sweatingNausea, vomiting, bradycardia, sweatingRapid visual deterioration:Rapid visual deterioration:Severe increase in IOP, corneal oedemaSevere increase in IOP, corneal oedemaReduced central visionReduced central visionPupil semi-dilated, oval, unreactive to light Pupil semi-dilated, oval, unreactive to light

Acute Glaucoma: DiagnosisAcute Glaucoma: Diagnosis

Ocular emergency (spontaneous attack)Ocular emergency (spontaneous attack)

Patient history and clinical picturePatient history and clinical picture

Tonometry: severe elevation IOPTonometry: severe elevation IOP

OphthalmoscopyOphthalmoscopy

GonioscopyGonioscopy

PerimetryPerimetry

Acute Glaucoma: ManagementAcute Glaucoma: Management

Acute emergencyAcute emergencyTopical (eye drops):Topical (eye drops):Hyperosmotics (Diamox) ↓ IOPHyperosmotics (Diamox) ↓ IOPMiotics (Pilocarpine) contract ciliary body Miotics (Pilocarpine) contract ciliary body constricting pupil → open trabecular meshconstricting pupil → open trabecular meshββ - blockers: reduce aqueous production - blockers: reduce aqueous productionLaser iridotomy: releases aqueous ↓ IOP Laser iridotomy: releases aqueous ↓ IOP Other eye treated to prevent further attackOther eye treated to prevent further attack

Glaucoma: Nursing ConsiderationsGlaucoma: Nursing Considerations

Patient education about condition:Patient education about condition:Importance of punctuality with eye drops. Importance of punctuality with eye drops. Check patient or relative instilling correctlyCheck patient or relative instilling correctlyImportance of regular follow-upImportance of regular follow-upPost-laser: Monitor for transient rise of IOP Post-laser: Monitor for transient rise of IOP (closure of iridotomy), haemorrhage, (closure of iridotomy), haemorrhage, uveitis and blurringuveitis and blurringAwareness of life-style aids where vision Awareness of life-style aids where vision severely impaired. Emotional supportseverely impaired. Emotional support