- Prism Adaptation Study
- Randomized controlled trial
- Provides an evidence based paradigm for treatment
- Acquired Esotropia
- Partially Accommodative Esotropia
- Esotropia with Near > Distance
- Exotropia has not been investigated thoroughly with this procedure
- Add Fresnel prism to glasses
- Try to split prism equally with larger prism over eye with worse acuity if needed
- Non-Responder
- Orthotropic but no sensory response
- Keep prisms on and check immediately before surgery
- Exotropia of any size
- Stop and do surgery for entry angle
- Responder
- ≤ 8 Prism Diopers on Simultaneous prism cover test at distance and near and
- Peripheral fusion on Worth 4 Dot test or
- Stereo response on Titmus Stereo test
- Surgery for angle at response
- Builder
- > 8 Prism Diopters on Simultaneous prism cover test
- Add more prism and recheck in a week
| Target Angle (PD) | BMRc | LRs (one eye) |
|---|---|---|
| 12 - 15 | 3.0 | - |
| 16 - 20 | 3.5 | - |
| 21 - 25 | 4.0 | - |
| 26 - 30 | 4.5 | - |
| 31 - 35 | 5.0 | - |
| 36 - 40 | 5.5 | - |
| 41 - 45 | 6.0 | - |
| 46 - 50 | 5.0 | 5.0 |
| 51 - 55 | 5.0 | 6.0 |
| 56 - 60 | 5.0 | 7.0 |
oculoman