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Current Trends in Diagnosis and Management of Glaucoma
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Current Trends in Diagnosis and Management
Characteristic damage to the optic nerve leading to progressive, irreversible vision loss with or without elevated intraocular pressure
Characteristic damage to the optic nerve leading to progressive, irreversible vision loss with or without elevated intraocular pressure.
Significantly elevated intraocular pressure with or without visual field changes or obvious nerve or nerve fiber layer damage
3-4 million in US2.2 million over 40 have glaucoma50% undiagnosedPresent in 1 in 200 over 50 and 1in10 over 80The percentage of Americans over 65 will grow
by 50% in the next 15 years
AgeRefractive errorRace, ethnicityFamily historySystemic disease: HT, diabetes, obstr. sleep
apnea Medications - systemic and ocular, NAG and
OAGPrevious ocular trauma or surgeryDevelopmental and other ocular conditions
1980 - 90’s - initial state laws for OD’s to treat glaucoma
NM one of the first 2000-2005 - most states pass glaucoma therapy
for OD’s. Oklahoma allows lasersEven now, up to 50% 0f OD's still refer non-
complex, non-surgical glaucoma cases to OMD’s
Multiple reasons for not treating – experience, cost of instruments, practice focus, office size, patient mix
Miotics, sympathomimetics and orals – used in early to late 1900's
Trabeculectomy developed in the 1960'sBeta blockers introduced in the mid 1970'sLasers since the mid to late 70'sMultiple new meds and procedures from 2000
to present have led to a 50% reduction in vision loss in glaucoma patients from 1980 to present
Open Angle - POAG/Low Tension Secondary - pigmentary, pseudoexfoliative, inflammatory, phacogenic, traumatic, hemorrhagic, neovascular, drug-induced, malignant - intraocular surgery related
Developmental- those associated with inherited disorders
Narrow and closed angle
90% of all casesGood response to meds and lasersMost patients controlled with medsMany undiagnosedRate rising with increasing BMI, DM and the
aging population
Relatively rare, but still underdiagnosedMany forms/multi-factorial/mixed mechanismTypically more severe than OAGMost common in older female hyperopes and
Chinese- smaller eyes, fatter lensesIntermittent or chronic narrow angle Acute angle closure – emergency
Lens vault – forward position of lens relative to SS – pupillary block most common mechanism
Plateau iris – abnormally positioned ciliary body pushes peripheral iris on to TM
Phacogenic – cataract-induced lens thickening, PXE - 10% of cases have angle closure component
Thickened, dense iris – less sponge effect on dilation
Shallow anterior chamber – anterior iris insertionScleral buckles, malignant glaucoma
PI for those with hidden posterior TM > 180 deg.Gonioscopy – small beam, outside pupil, dark
conditionsVerify with OCT if possiblePosition at 11 or 1o’clock, usually hidden by eyelidAway from superior lacrimal riverYAG most commonDone early, before significant, persistent pressure
rise30% have minimal response – done too late, plateau
Occasionally done for non-responsive PI casesNo well designed studies to validate
effectivenessMost often performed in plateau iris that does
not move from apposition to TM after PIArgon laser to mid periphery of iris, shrinks
tissue at laser site, pulling iris away from angle
Sectoral or circumferential
Especially effective for plateau iris, recent acute angle closure and lens vault cases
Less effective in chronic NAG casesMuch less risk than trab in narrow anglesCan be combined with iStent for better IOP
reduction
Slow process of conversionInitially, intermittent iris / TM contact is seenLater persistent pigment on TM and
synechiae formationPressure slowly rises, sometimes fluctuating
with iris positionWatch for angle closure in POAG patients
who fluctuate
Often severe pain, but not alwaysCloudy vision in all cases, fixed pupil, cells in ACIOP can be 40-60+Don’t use PA’s- inflammatory - instead PrednisoloneStart with combigan 0r simbrinza q10-15 minOnce IOP lower than 30, add pilocarpine 1-2% qidUse oral CAI or 50% glycerine if unresponsive, > 50Diamox 250 or 500 po q 4-6 hrs, not SequelsArrange for PI, keep pt. on low dose pilo until laser
Extrinsic- medication, trauma, burns, infection/inflammatory, toxic, post surgery
Intrinsic- phacogenic, pigmentary, pseudoexfoliative auto-immune/inflammatory, neovascular, tumors, RD, others
Extremely rareSurgery neededPrognosis poorClassic presentations congenital, infantile, juvenile and glaucoma
assoc. with hereditary familial diseases
Large cupsAsymmetry in IOP or cup/disc ratioHigh IOPLow CCTFamily history or history of traumaNo NFL dropout or classic optic nerve signsNo VF defectsNo SLO, OCT or GDX defectsLTG suspects – collagen and autoreg. disorders
Serial tonometry prior to tx if no history of IOP’s available
ON evaluation/stereo photosGonioscopyVisual fieldsPachymetryOCT, SLO, GDXBP for Ocular Perfusion Pressure calculationFamily oc. hx. and patient medical/sx history
Goldmann is the standard but has some limitations
Alternatives - Pascal, Tonopen, pneumatic, rebound
CCT affects accuracy of measurements in someCCT a guide to modifying risk - not a true and
accurate adjustment factorRK, PRK, LASIK, corneal scars and KC can all
affect corneal thickness and hysteresisORA – measures hysteresis and “corrected
IOP”
Billed once in glaucoma management Importance documented in OHTSOne third with IOP over 26 and cct < 555 - dx
GLC6% with same iop and cct > 588 dx GLC Relative risk increased 81% for every 40
microns < 555
Rim: focal erosions/generalized cuppingISNT rule/verticalization of cupDisc size and depthDisc heme at or near rim marginBayonetting of vessels/saucerization of discBeta zone pigment changesNFL dropout with red-free filter
SITA automated perimetry is the standard for following progression on established cases 24 or 30 degrees – correlate with clinical findings
10 degree fields gaining acceptanceMatrix FDT is more sensitive for early
detection but not as reliable for progression analysis
Look at quality and repeatability of the testRarely make major decisions or changes with
only one field study
SD OCT now the standard of care with cRNFL, GCC and anterior chamber capability
Reliable and repeatable, but not infallible
High myopes may be false positives
Swept-Source an upcoming technology, but cost/reimbursement an ongoing issue
SS is faster, less errors, more detail, with additional choroid thickness measurement
Older models best for nerve head contour analysis, and PPRNFL thickness (no GCC)
NFL thickness analysis not as accurate as SD-OCT, especially in larger nerves
Good database for normative comparison
Only PPNFL thickness measured using polarized light
Fairly repeatable Relatively inexpensiveTechnology 15+ years oldSmall footprintStill useful for comparative data in
questionable cases
Manual technique for angle evaluation, not billable using OCT, Pentacam, etc
Used to rule out closed/narrow angles and angle recession and to determine risk of closure
Note most posteror structure in sup and inf angles and iris approach – flat, convex, concave, plateau
Also used to assess pigment or debris in the angle, grading 1-4
Takes experience and time, 3 vs 4 mirrorNot done as routinely as other testing by many
Relative pressure differential between diastolic systemic blood pressure and intraocular pressure
OPP = DBP-IOP target >50-55Important in establishing target IOP range in
treatment or in the evaluation of need for treatment
Very important in LTG, BP lowest at nightPA’s moderate effect, BB zero effect on nocturnal
IOP. CAI’s have best effect overnight but rx’d TID
ON damage with IOP never above 21Lower blood flow and choroidal thickness in
parapapillary regionCollagen issues – sleep apneaAuto-regulatory issues – Raynaud’s, migrane synd.Low BP, over medicated htn pt?Low OPPDisc heme more commonNo beta blockers, add NaCl to diet at evening
meal
Topical or oral meds – safety, tolerability, efficacy and compliance issues
Lasers – safe but short duration of effectTrabeculectomy – good effect, but safety
concernValves/Shunts gaining on trabsMIGS – unproven in wide usageEmerging treatments – Sub-conjunctival
injections, med-releasing plugs and CL's
AgeRaceONH appearance, cNFL /GCC and VF
damageSystemic healthBaseline IOPBP
General target 20-30 % reduction from TmaxMild cases 20-30%Moderate cases 30-40%Severe 40-50%< 12.5 mmHg limits VF progression in most
cases
Prostaglandin analoguesAlpha agonistsBeta blockersCarbonic anhydrase inhibitorsFixed combinations
Steroids in inflammatory cases
Xalatan – latanoprost lasts up to 36 hrs.Travatan Z - BAK free, lasts up to 60 hrs.Lumigan - same drug as Latisse, different conc.Zioptan – PF unit dosesAll increase uveoscleral outflowLumigan also said to increase TM outflowNo racial differences in effectsContraindications – HSV, CME, iritisAdverse effects – red eyes, PAP
Only one drug available in US for long term use
Not for pediatric patiets - pulmonary issuesAlphagan P or brimonidine (generic) 0.1-0.2 %Different preservatives/vehiclesProprietary version ? less prone to allergic
responseAvailable in combination with a beta-blocker
as Combigan and with CAI as Simbrinza
Timolol, Levobunolol, BetaxololTomolol 0.25 and 0.5 % solutions and 0.5% gel
forming suspension, dosed bid and qdOriginated in mid 70’s, reduces aqueous prod.Adverse effects include bradycardia, reduced
energy, depression, pulmonary probs and ED Monitor blood pressure and pulse in high risk
indiv.Available as PF unit doseIn combo drug with CAI as Cosopt
Dorzolamide Brinzolamide both decrease aqueous productionUsed TID if monotherapyBID if in fixed combo with beta blocker
timolol- Cosopt – available as generic and PFTID in combo of brinzolamide/brimonidine –
Simbrinza. Avoid in sulfa allergiesPO options – short term, diamox, neptazane
Combigan – brimonidine and timolol Cosopt – brinzolamide and timolol – avail.
genericSimbrinza – brinzolamide and brimodine
All good as primary or additive therapy to prostaglandin analog
SLT- Selective Laser Trabeculoplasty – 3-5 yr effect, repeatable
ALT- Argon Laser Trabeculoplasty – 3-5 yr effect, not repeatable
TrabeculectomyValves – Molteno, Ahmed, BarveldtCanaloplastyMIGS – iStent with cat. sx., ECP, TrabectomeCataract sx in lens vault narrow angles and
pseudoexfoliative cases, open angle cases due to molecular mechanism from ultrasound/phaco
Glaucoma workup- typically two to three visits Ongoing care – intermediate E/M visit q 3-4 mo.VF 3-12 months depending on reliability, IOP’sHRT/OCT/GDX q12 monthsStereo disc photos q12 monthsPatient/physician referrals