Review of Glaucoma Suspect Shields’ Textbook of glaucoma, 6th edition Becker-Shaffer's diagnosis and therapy of the glaucomas, 8th edition

Introduction Glaucoma suspect Shields’ Textbook of glaucoma 6th edition (2010) Ocular hypertension 1970s: IOP greater than 21 mmHg, → higher risk for developing COAG Chandler & Grant: early open-angle glaucoma without damage Glaucoma suspect Shaffer: Glaucoma suspect Consistently elevated IOP(>21mmHg) optic nerve features suggestive of early glaucoma suspicious visual field defects

Definition Normal appearing, open angle by gonioscopy, and one of the following in at least one eye IOP consistently above 21 mm Hg by applanation tonometry Appearance of the optic disc or retinal nerve fiber layer suggestive of glaucomatous damage Diffuse or focal narrowing or sloping of the disc rim Diffuse or localized abnormalities of the nerve fiber layer, especially at superior and inferior poles Disc hemorrhage Asymmetric appearance of the disc or rim between fellow eyes (e.g., cup to disc ratio difference greater than 0.2) suggesting loss of neural tissue Visual fields suspicious for early glaucomatous damage Adapted from AAO, PPP, 2000

Prevalence and development of Open-Angle Glaucoma The Glaucoma Suspect ‘Natural history’ of treated and untreated open-angle glaucoma An individual without glaucoma. Subthreshold axonal loss from glaucoma that does not progress beyond category. Axonal loss from glaucoma that responds to treatment(*) compared to Glaucoma that remains untreated because of a delay in diagnosis. Aggressive axonal loss from glaucoma that is detected only after the onset of symptoms and progress to blindness despite treatment(**). Shields’ Textbook of Glaucoma

PREVALENCE AND DEVELOPMENT OF OPEN-ANGLE GLAUCOMA Prevalence rate : 4% to 10% in persons older than age 40 years(IOP greater than or equal to 21 mm Hg in one or both eyes (with normal visual fields and optic nerves)) Progression rate to COAG : approximately 1% per year over 5 to 15 years

OHTS (Ocular Hypertension Tx Study) Design Multicenter, randomized, prospective clinical trials Purpose To determine the efficacy of topical med. in delaying or preventing the onset of glaucoma in OHT Subjects 24-32mmHg (21-32mmHg in other eye) 1636 pts between 40-80 yrs Topical ocular hypotensive treatment versus close observation 7

OHTS (Ocular Hypertension Tx Study) Treatment goal <24mmHg and at least 20%↓ COAG developing over 5 years 1% / year in the medication group 2% / year in the observation group High risk factor (+) → 3~5% / year 8

High-Risk Glaucoma Suspects High-risk glaucoma suspects include patients who have one or more of the following: IOP consistently > 30 mm Hg* Thin central corneal thickness(dependent on ethnicity) Vertical cup-to-disc ratio >0.7 Older age* Abnormal visual field, e.g., increased pattern standard deviation on Humphrey Visual field test. Presence of exfoliation or pigment dispersion syndrome. Disc hemorrhage Family history of glaucoma or known genetic predisposition. Fellow eye of patient with severe unilateral glaucoma(excluding secondary unilateral glaucoma) Additional ocular(e.g., suspicious disc appearance, myopia, low optic nerve perfusion pressure, steroid responder) or systemic risk factors that might increase the likelihood of developing glaucomatous nerve damage (e.g., African ancestry, sleep apnea, diabetes mellitus, hypertension, cardiovascular disease, hypothyroidism, migraine headache, vasospasm) *These factors were identified as risk factors for development of chronic open-angle glaucoma in the Ocular Hypertension Treatment Study and European Glaucoma Prevention Study..

Screening IOP value of more than 21 mm Hg Skilled optic nerve examination Goldmann kinetic or Humphrey static (automated) perimetry short wavelength automated perimetry (SWAP) standard automated perimetry (SAP) Frequency doubling perimetry (FDP) Best method to detect early galucoma (AAO) IOP, optic nerve and visual field.

DIAGNOSTIC ASSESSMENT IOP AND PACHYMETRY 2.5 mmHg ~ 3.5 mmHg should be applied for every 50 microns of difference from 550 microns SLIT-LAMP BIOMICROSCOPY AND GONIOSCOPY To exclude angle closure or secondary cause of elevated IOP angle recession, pigment dispersion, KP on the trabecular meshwork FUNDUS EXAMINATION optic nerve head, disc hemorrhage, nerve fiber layer VISUAL FIELD 24-2 SITA, 24-2 Humphrey perimetry, SWAP, FDP (Matrix) IMAGING of OPTIC NERVE and NFL Confocal laser scannig tomography, OCT, scanning laser polarimetry OCULAR BLOOD FLOW Doppler flowmetry Lower in superotemporal rim (16% lower), the cup (35%), and the inferotemporal neuroretinal rim (22%)

When To Treat? Complex decision that involves consideration of many factors Visual, physical, medical, psychological, and social circumstances

Indication for treatment if early damage is detected or if the patient appears to be at high risk for developing POAG based on the risk factors if the IOP is 30 mmHg or greater prevalence of glaucoma at this pressure level is 11–29% 3. IOPs in the middle-to-upper 20s who also have one or more risk factors Becker-Shaffer's diagnosis and therapy of the glaucomas, 8th edition

Possible indication of treatment 1. A one-eyed patient. 2. A young patient. high pressure for many years vs more resistant to the effects of elevated IOP 3. Unreliable visual fields or optic disc assessment.. 4. A patient who is content with treatment initiated by another physician and who is tolerating the medication well. 5. An ocular hypertensive patient who desires treatment. 6. An ocular hypertensive patient who has developed a vascular occlusion in either eye. Becker-Shaffer's diagnosis and therapy of the glaucomas, 8th edition

Treatment in Glaucoma Suspect with elevated IOP Stratify pts. High risk : Suggest treatment be initiated Mod. risk : Can initiate treatment if appropriate, or monitor closely Low risk : Monitor IOP as well as optic nerve structure and function, and treat if evidence of progression Carefully consider theses factors when deciding whether to treat. Greater age and life expectancy Psychological factors Convictions(patient and physician) Social environment Availability for follow up Pregnancy

Various Types and Managements of Glaucoma Suspect Becker-Shaffer's diagnosis and therapy of the glaucomas, 8th edition

Glaucoma Suspect Type I Glaucoma Suspect Type II Normal Intraocular Pressure, No Damage Strong family history of glaucoma Retinal vascular occlusion Exfoliative syndrome Angle recession Pigmentary dispersion syndrome Narrow angles Uveitis History of halos Management : Monitor periodically and inform patient of need for follow-up Glaucoma Suspect Type II Normal Intraocular Pressure, Possible Damage Suspicious optic disc Suspicious nerve fiber layer defects Suspicious visual field Reduced psychophysical function Management : Confirm the finding by repeat testing if needed, as with suspicious visual fields. Demonstrate a normal variant, another cause of damage, or an elevated intraocular pressure(IOP) expressed at other time. If the patient demonstrates increased IOP, then treat for glaucoma. Otherwise. Treat any other existing disease or conduct annual or semi-annual examinations depending on risk factors.

Glaucoma Suspect Type III Glaucoma Suspect Type IV High Intraocular Pressure, No Damage Management : 1. Pressure > 35 mmHg(some authorities choose > 30 mmHg) : Risk of damage is great. Treat. 2. Pressure 25-30 mmHg : Treat if (1) other eye has damage, (2) patient is elderly or has siblings or parents with glaucoma, (3) patient has other risk factors, (4) patient has complicating ocular or vascular disease, or (5) there is poor patient follow-up or poor compliance. If treatment is poorly tolerated, treatment may be stopped and the patient observed at least every 5 months for progression of the disease. 3. Pressure 21-24 mmHg : Treat if other eye has damage. Otherwise, observe. Some authorities would treat if the risk factor(s) above exist. 4. Pressure ≥ 25 mmHg and very narrow angles : consider laser iridotomy. Glaucoma Suspect Type IV High Intraocular Pressure, Possible Damage Peripheral anterior synechiae and narrow angles Notch or local rim narrowing of optic nerve Early arcuate scotoma or paracentral scotoma Management : Generally, treat such eyes, especially if the other eye has damage, the patient has strong family history, or the patient has a complicating ocular disease.

Follow up IOP, optic nerve head, visual field status Depends on several factors Receiving medical therapy Target IOP range Risk factor At least 6 to 12 months At each visit, IOP Visual field : once every 6 to 18month Gonioscopy: suspicion of angle closure or other angle abnormality

Follow up

OHT Follow-up From EGS guideline 3rd edition (2008) Follow-up at intervals of 12 months initially, to be increased if all parameters remain negative, with exam: Optic disc VF IOP ONH & RNFL photographs initially and every 2-3 years