Learn Connect Succeed. JCAHPO Regional Meetings 2017

Transcription

1 Learn Connect Succeed JCAHPO Regional Meetings 2017

2 Refractometry: Knowledge and Skills for Today s Technicians Matthew L. Parker, PhD, LSSMBB, COMT, CST, OSC U.S. Army (Retired) I have absolutely no financial interest in any of the products shared in this presentation. Director of Strategic Initiatives Joint Commission on Allied Health Personnel in Ophthalmology M. Parker Objectives REFRACTOMETRY Relate Optics with Prescription Eyewear Perform Manifest Refraction, Apply PACT Performance & Teaching Methods Describe Various Basics Techniques Results P A C - T Retinoscopy Refinement Overview of Refraction Binocular balancing Prescription of spectacle lenses keep the patient history in mind Correction of Refractive Errors Spectacle Lenses Contact Lenses Keratorefractive Surgery Intraocular Lenses Clear Lens Extraction for Myopia 1

3 Overview of Ophthalmic Optics Refractive States of the Eye Principles of Vergence (Power) Types of Lenses Sphere, cylinder, spherocylinder Focal Point(s) Prisms* Lens Notation Ocular Considerations Lens Transposition Spherical Equivalent Lensometry - Assisted Accommodation Strabismus Contact Lens wear Surgical Planning Post surgical refraction Trauma Monocular or Anophthalmia Where do you start? Estimating Technique Old School Plano, retinoscopy, estimating technique New School Auto refractors, current glasses, last manifest refraction in chart 2

4 The Lens in the Pocket Lights On or Lights Out? Refinement Quick Steps Dial in your starting point Careful instructions to patient Present 20/40 line (not best VA line) Adjust sphere Refine cylinder axis Refine cylinder power Refine sphere Duochrome Test Binocular Balancing Fogging Prism dissociation Bifocal add power Cycloplegia What s Next? Near Point and Reading Add Refinement Review Common Pluses and Minuses Refinement Review Common Pluses and Minuses Choose starting point Instruct patient Occlude untested eye Refine sphere power Introduce cross cylinder Adjust cross cylinder to measure axis Refine the cylinder axis Adjust cross cylinder to measure power Refine cylinder power Adjust sphere power as necessary Remove cross cylinder Re-refine the sphere Red/green filter assessment Assess visual acuity record results 3

5 General Prescribing Guidelines Prescribing for Myopes Prescribing for Hyperopes Prescriptions for Astigmatism Prescriptions for Presbyopes Interpupillary Distance General Prescribing Guidelines Asymptomatic, do not prescribe new glasses Minor changes are risky Vertex distance considerations Considerations for cylinder axis Trial frame fitting is extremely useful Prescribing for Myopes Careful not to over-refract Use results of cycloplegic retinoscopy and refraction to avoid over-refraction Careful in adults over 40 not to induce presbyopic symptoms Prescribing for Hyperopes Be wary of asthenopia and visual discomfort Be wary of bifocal headaches Prescribing for Astigmatism With very young children, prescribe the full astigmatic correction and advise full time wear Careful in consideration of axis of astigmatic correction Ascertain that any new astigmatic correction produces significant improvement in both distance and near Be wary of intolerable distortion Advise period of adjustment Prescribing for Presbyopes Medication history of barbiturates, antidepressants, antihistamines and decongestants can exacerbate presbyopia Bifocal adds of or less are rarely necessary Alternative to single vision reading glasses is plano top bifocals 4

6 Pitfalls & Pointers Working Posture Clearly see and understand with motion and against motion Don t fear those irregular reflexes Manifest means without cycloplegia Eye dominance (don t ignore this!) Lights on or lights out? With practice, techniques become manageable. Not Just for Glasses Myopic Shifts Hyperopic Shifts The Prescription comparison before released Pre- and post-operative considerations Making sense of other data (i.e. AEL) Pointers Investigate large shifts or changes in prescription Retinoscopy at any time Avoid over minus (Spherical Power) Avoid big cylinder changes (Easier adjustment) Eye dominance (don t ignore this!) Lights on or lights out? With practice, techniques become manageable. Pointers The Prescription comparison before released Speed is not necessary Keep both eyes open 5