Tips for Handling BV without VT

Transcription

1 Tips fr Handling BV withut VT Catherine McDaniel, OD, MS, FAAO Objective: Attendees will learn diagnsis f cmmn nn-strabismic bincular visin cnditins and treatment f these cnditins using techniques ther than visin therapy. Symptms: - Chief cmplaint- make sure t ask: Eyestrain Headaches Duble visin Blurred visin Wrds mving arund n page Skipping lines while reading Difficulty keeping place when reading Tired when reading - Secndary CC If find an abnrmal BV finding during exam make sure t ask! - Symptm survey CISS Symptmatic scre: Adults 21 Kids 16 Tls: - Refractive errr Dn t underestimate the pwer f apprpriate refractive crrectin! Retinscpy vs. autrefractin Cyclplegia when necessary D NOT test BV until best crrectin in place! - Ocular alignment Free space vs. phrpter Cver test Fixatin target 20/30 single letter Must stimulate acc m at near fr accurate result Stress target clarity Prism neutralizatin: must get sustained reversal Fr strabismus: Frequency: cnstant r alternating Laterality: unilateral r alternating Directin: es, ex, hyp, hyper Maddx rd Remember: Maddx ROD ver Right eye Lse prism neutralizatin Variable prism Mdified Thringtn

2 - Accmmdatin Amplitude Repeat 3 times and lk fr fatigue Average: (age) Minimum: (age) Facility Bincular and mncular +/-2.00 flippers Timed 1 minute Nrms: 13-30y 10cpm binc, 11 cpm mnc 8-12y 5cpm binc, 7cpm mnc Accuracy MEM Retinscpe, MEM cards Neutralize reflex in each eye while pt reading frm MEM card Testing at their reading distance NOT yur typical retinscpy distance Nrmal: Vergence Ranges Prism bar Nrmal values: Distance BI: x/7/4 BO: 9/19/10 Near BI: 13/21/13 BO: 17/21/11 Facility 12BO/3BI split prism Timed 1 minute Nrmal value: 10cpm - Stereacuity Want a stere test that lks at bth: Lcal r cntur sterepsis Glbal r randm dt sterepsis: ensures bifveal fixatin AC/A rati: - Definitin: The measurement f the cnvergence induced by accmmdatin per dipter f accmmdatin.

3 - Tw ways t determine: Calculated PD + d(n-d) PD in cm d: near fixatin distance in meters N: near CT, D: distance CT Es is plus, ex is minus Gradient Phria measured with and/r lenses in place Change in phria ver the change in accmmdative demand is the AC/A - Nrmal value: 4/1 ±2 - Why are the calculated and gradient AC/A different? Prximal vergence Lag f accmmdatin Bincular Visin Cnditins: - High AC/A Cnditins Cnvergence Excess Diagnsis: EP > near Make sure t use gd acc m target fr CT! High lag n MEM Reduced BI vergence ranges at near Truble with minus n BAF Lwer acc m demand at near lessens EP Divergence Excess Diagnsis XP > distance Reduced BO vergence ranges at distance Added minus at distance Increase acc m demand t increase acc m cnvergence and lessen XP Make sure t check acc m amplitudes if Rx ing ver-minus Cnsider an add at near t cunteract ver-minus - Nrmal AC/A Cnditins Basic Es Diagnsis Equivalent EP at distance and near Reduced BI at distance and/r near Lenses vs. Prism Lenses Added plus at near: can cnsider if Pt is symptmatic at near Has small EP

4 Prism BO prism: can cnsider if Pt is symptmatic at distance Is symptmatic at near and has larger EP Percival s criteria 1/3 greater lateral range 2/3 lesser lateral range Assciated phria Basic Ex Diagnsis: Equivalent XP at distance and near Reduced BO at distance and/r near Lenses vs. Prism Lenses: Added minus at distance: can cnsider if Has small XP Prism: BI prism: can cnsider if Has a larger XP Sheard s criteria 2/3 phria 1/3 cmpensating fusinal vergence - Lw AC/A Cnditins Divergence insufficiency Diagnsis: EP > distance Reduced BI range at distance Prism: Percival s criteria Other cnsideratins if pt diplpic: nset, cause Cnvergence insufficiency Diagnsis XP > near Reduced BO range at near Receded NPC Prism? Sheard s BI prism fr CI study (CITT Study Grup 2005) BI prism glasses n mre effective in alleviating symptms than placeb reading glasses

5 - Accmmdative Prblems Accmmdative insufficiency Diagnsis Reduced accmmdative amplitudes High lag n MEM Truble with minus n accmmdative facility - Other Accmmdative spasm Diagnsis Eating minus n refractin Lead n MEM Truble with plus n accmmdative facility Best refractive crrectin! Vertical phrias Diagnsis CT, Maddx Rd, assciated phria Expanded vertical vergence ranges Prism Assciated phria (BD t break BU t break)/2 Result is plus BD Result is minus BU Dem it