GLAUCOMA LOOK OUT One of the leading causes of blindness
Visual loss is irreversible Early diagnosis and proper management is important Not A Single Disease A group of disorders characterized by:
A progressive optic neuropathy resulting in a characteristic appearance of the optic disc, and a specific pattern of irreversible visual field defects, that are associated frequently but not invariably with raised IOP. {NTG ; OHT} Classification Open Angle Glaucoma: A- Primary (POAG)
B- Secondary(SOAG) Angle Closure Glaucoma: A- Primary (PACG) B- Secondary(SACG) 3. Congenital & Developmental Glaucoma: A- Primary Congenital Glaucoma B- Developmental Glaucoma (with associated anomalies) Pathogenesis of Glaucomatous Ocular Damage
Retinal ganglion cell death with loss of retinal nerve fibers due to: Raised IOP (mechanical theory) Pressure independent factors (vascular insufficiency theory) Chronic glaucoma: what is happening
Or poor blood supply here Either: the drain blocks here Damages the optic nerve..looks caved in, called cupped POAG Chronic Simple Glaucoma
Triad (Criteria of diagnosis) RISK FACTORS: Heredity. Age (5th-7th decade) Race (Black) Myopia. Retinal disease e.g. RP, CRVO DM Hypertension Central corneal thickness PATHOGENESIS OF IOP RISE
Impaired aqueous flow after the level of the angle e.g. Trabecular sclerosis. CLINICAL FAETURES SYMPTOMS : ASYMPTOMATIC UNTILL TOO LATE
PERIODIC CHECK UP after middle age. Mild headache, eye ache, frequent change of reading glasses, delayed dark adaptation. SIGNS : Raised IOP: Normal value Diurnal variation NTG ,OHT
Tonometry: {Digital, Indentation,Applanation, pneumatic tonometer,tonopen} Normal central corneal thickness: 545 550 u
Add or subtract 2.5 mmHg for each 50 u change in central corneal thickness Glaucoma tonometry (pressure test) Signs (Cont.) 2. Optic disc changes: Cupping ( normally up to 0.4)
Large Asymmetry Progressive Vertical Notching Pallor Splinter hemorrhage Nerve fiber layer atrophy Marked cupping, nasal shift of blood vessels and CRA pulsation. Glaucomatous optic atrophy Glaucoma damage SIGNS (Cont.) 3. Specific Visual Field Changes:(Perimetry)
Initially observed in Bjerrum area (10 30 degrees from the fixation point ) Small paracentral scotoma. Siedel scotoma (paracentral scotoma join the blind spot to form a sickle shaped scotoma) Arcuate scotoma (Siedel S. extend either above or below the fixation point) Ring (double arcuate) scotoma. SIGNS (Cont.) 5. Roenne central nasal step.
Roenne peripheral nasal step. Temporal wedge Tubular vision Temporal island of vision. PERIMETRY HUMPHRY VFA FREDQUENCY DOUBLING PERIMETER SHORT WAVE AUTOMATED PERIMETER (SWAP) GOLDMANN PERIMETER SIGNS (Cont.) 4-. Wide open angle on Gonioscopy. NB.
Slit lamp examination to rule out causes of SOAG. Documentation of optic disc changes is very important. Recent tests e.g. Nerve fiber layer analyzer (NFLA) Optical coherence tomography(OCT) MANAGEMENT EVALUATION & ASSESSMENT TARGET PRESSURE TEHRAPEUTIC CHOICE
MEDICAL ALT or DLT FILTRATION SURGERY MONITORING & FOLLOW UP MEDICAL THERAPY TERATMENT IS ESSENTIALLY MEDICAL
TOPICAL DROPS (ORAL IS UNSUITABLE FOR LONG TERM TREATMENT) SINGLE OR COMBINATION Aim is to lower IOP Decrease aqueous production Increase aqueous drainage. MEDICAL (Cont.) Topical beta blockers: decrease Aq. production
Timolol maleate (0.25, 0.5% BD) Betaxolol (0.25% BD) in asthma. Levobunolol (0.25, 0.5% once daily) Carteolol (1% BD) low effect on lipoprotiens . SE & Contraindications? Pilocarpine (1- -4%, QDS): increase Aq. Outflow Ocular SE ? Systemic SE ? 3)Latanoprost (PG F2alpha analogue 0.005%, once daily) Increase uveoscleral aq. Outflow Expensive MEDICAL (Cont.) 4) Dorzolamide (2% TDS ,carbonic anhydrase inhibitor), decrease Aq. Production 5) Adrenergic drugs: Epinephrine hydrochloride & Dipivefrine hydrochloride , increase outflow. Brimonidine (0.2%, BD), decrease Aq. production. ALT Laser shots at the ant. part of TM will lead to stretching of adjacent area of TM Indication Failure of maximal tolerated medical therapy. Non compliance to medical therapy Filtration surgery TARBECULECTOMY
To create a fistula between AC & subconjunctival space thus provide a new channel for Aq. outflow Indication: Failure of medical & ALT Non compliance Non availability