1 / 18

M. M. Parks

Surgical management of partially accommodative ET with convergence excess DR ELINA LANDA OCULAR MOTILITY RVEEH JOURNAL CLUB EDITED BY LIONEL KOWAL. Convergence excess ET – ET with D/N disparity, where the near angle exceeds the distance by more than 10∆( with or without high AC/A ratio)

toril
Download Presentation

M. M. Parks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Surgical management of partially accommodative ET with convergence excessDR ELINA LANDAOCULAR MOTILITY RVEEH JOURNAL CLUBEDITED BY LIONEL KOWAL

  2. Convergence excess ET – ET with D/N disparity, where the near angle exceeds the distance by more than 10∆( with or without high AC/A ratio) • Surgical goals: 1 Alleviate symptoms 2 Reduce N deviation without altering D 3 Improve binocularity 4 Eliminate need for bifocals

  3. M. M. Parks • BMR is the best surgery resulting in AC/A ratio improvement by 66% • Standard surgery for partially accom ET was based on residual deviation for dist with full correction. 50%- rate of undercorrections • Parks suggested (1975)to add 1mm to each MR rc in pts with conv excess ET : - significant undercorrection rate - no success in eliminating the bifocals (1/3 with bf)

  4. Augmented BMR by Kushner • Augmented rc- BMR+1mm if N-D 10∆ BMR+1.5mm 15 ∆ max 6.5mm BMR+2.0mm 20 ∆ “Comparison augmented BMR with BMR & faden” Outcomes:- alignment follow up 5 years - bifocals - spectacles

  5. Kushner: Augmented BMR 15y outcome • 22/25 were available • 86% good alignment: 27% alignment +correction for alignment 36% with correction for VA 23% w/o correction • 3/22 unsatisfactory results: 1/3- recurrent ET 2/3 XT

  6. Augmented BMR by Wright for ET with high hypermetropia • Pt: Dsc 40ET; Nsc 50E Dcc 20ET; Ncc 30ET • Standard Dsc+Dcc/2 25pd • Augmented Nsc+Ncc/2 40pd • Refr b/w +3 to +9 • Conv excess 10/30 SG 12/40 AG

  7. Kushner: should you overcorrect and cut the plus?

  8. Augmented BMR using the Prism Adaptation Test • The preoperative use of prisms to determine the max angle and estimate fusional potential • 60% - prism responders 50% - St BMR 50% Aug BMR • Alignment within 8pd 79% 72% nonresp 89% • Long-term (3y) results (Rosenbaum) Alignment 76% PA sx vs 31% non PA sx

  9. PAT in convergence excess ET • Kutschke -65 pts with conv excess ET 31 sx for near PAT 34 for dist PAT 95% alignment 86% alignment 0 – need in bf 2/3 – bf Overcorrection – 9%

  10. PAT in convergence excess ET • Kraft – 65pts 83% responders 17% non- responders 72% align.+fusion 55% align. + fusion 76% alignment 73% alignment Unsuccessful 13pts 9 undercorrections 4 overcorrections

  11. Strabismus surgery for elimination of bifocals • 16pts 13/16 PAT+ 3/16 PAT- 10/13 – 1 surgery 1/13 – 1 surgery 2/13 cons XT 2/13 – cons XT 1/13 rec ET • Surgery is based on PAT for near angle

  12. Faden operation • Aim of faden is to weaken the EOM only in its field of action, not affecting ocular alignment in primary gaze • Peterseim and Buckly : 95%- norm. AC/A 70% - good motor and sensory fusion for near • Vivian : 95% success in decrease of near deviation and stereo

  13. Posterior fixation sutures- permanent suturing of muscle belly to sclera near the equator • A. Scott (The fadenoperation: mechanical effects. Am Orthopt J 1977) suggested a mechanical explanation: -moving the effective insertion to the equator results in torque reduction ( b/c of shortening of muscle’s lever arm for rotation of the globe) • J Demer (Posterior fixation sutures: a revised mechanical explanation… Am J Ophthal 1999): suggested an explanation based on rectus muscle pulleys: main mechanism - mechanical restriction of movement through the pulley

  14. Modifications to the fadenoperation • Intraoperative forced duction test • Minimize the amount of sharp dissection • The optimum position of the suture may be at the most posterior extent of the blunt dissection exposing the EOM

  15. 9 pts : standard BMR posterior fixation surgery with scleral sutures: 2 – only scleral faden 7 – BMRc + scleral faden Postoperatively: 6/9 – imroved stereoacuity 8/9 – no longer needed bifocals  D/N disparity average of 12∆ 13 pts : BMR  pulley posterior fixation: 3 – only pulley posterior fixation 10 – BMR +pulley post fixation Postoperatively: 8/13 – improved stereoacuity 12/13 – no longer needed bifocals  D/N disparity average of 14∆ Medial rectus pulley posterior fixation is as effective as scleral posterior fixation for acquired ET with high AC/A R A. Clark, J L. Demer Am J Ophthalmol 2004

  16. 3 recent pulley suture patientsPatient 1 • 5yo • Dcc 30pd; Ncc 50pd • Refr RT +2.5D ; Lt +3.0D • Sx: BMR 5.5 (Parks) + pulley post fix • 1mo postop: Dcc 6pd; Ncc 12pd

  17. Patient 2 • 14yo. • Swimming pool ET L only. +4 DS OU • Dsc 35pd Nsc 40 • Dcc 6pd Ncc 16pd • Sx: Lt MR pulley • 1mo after Dsc 20pd Nsc 20pd

  18. Patient 3 • 5yo • Dcc 25pd; Ncc 45pd • LET; Lt amblyopia 6/36 • Refr: RT +4.5D Lt +5.5D • Sx: BMR 5mm (for 35pd) + pulley post. fix. • 1week postop.: Dcc 12pd; Ncc 14pd

More Related