OPT505 Lecture 14: Building a Routine Refraction PDF

Attendance code: Attendance code: OPT505 Lecture 14: Building a routine refraction Ellie Livings  Attendance code: Intended Learning Outcomes Understand ‘basic routine’ Monocular v binocular refraction Binocular balancing Latent hyperopia ...

Attendance code: Attendance code: OPT505 Lecture 14: Building a routine refraction Ellie Livings  Attendance code: Intended Learning Outcomes Understand ‘basic routine’ Monocular v binocular refraction Binocular balancing Latent hyperopia  Attendance code: https://www.college-optometrists.org/clinical- guidance/guidance/knowledge,-skills-and-performance/the- routine-eye-examination Basic Minium Routine BR-TY-RN  Procedure for monocular refraction. (Follow the red arrows) Retinoscopy Occlude LE Un-occlude LE LE RE LE BVS BVS X-cyl X-cyl Refine sph Refine sph VA VA Plus 1 blur Plus 1 blur Occlude RE Un-occlude, BEO New concepts Binocular Balance Binocular Add (+0.25DS) Binocular considerations To have a comfortable visual Most people have two eyes which experience, we need BALANCE of work together= binocular accommodation between the eyes Eyes cannot operate Unbalanced accommodation may independently from an result in asthenopia, (and accommodation perspective rechecks) What’s the problem with occlusion? Occlusion dilates the pupil and may lead to refractive changes due to spherical aberration Occlusion manifests latent nystagmus and can make subjective refraction difficult Occlusion manifests cyclophoria and can lead to incorrect assessment of astigmatism Occlusion stimulates accommodation Accounting for accommodation and binocularity When we refract we either do it monocularly for each eye in turn and then binocular balance both eyes at the end OR We do it ‘all in one’’ binocular refraction If you blur back one eye, you suppress central vision, but the peripheral fusion is maintained to allow binocularity Plus 1 blur RE 6/6→6/12 RE 9 8 7 6 5 4 3 2 1 0 1 2 3 4 5 6 7 8 9 LE 6/6→6/9.5 LE 9 8 7 6 5 4 3 2 1 0 1 2 3 4 5 6 7 8 9 Accommodative Balance R L Monocular v Binocular Refraction Monocular refraction Binocular Refraction RE & LE RE LE Binocular balance included Plus 1 Plus 1 blur blur Binocular Balance Note: In those groups where binocular Binocular Add (+0.25DS) vision/accommodation is NOT a concern, use monocular subjective up to red line Subjective Refraction Monocular: Fellow eye occluded Binocular: fellow eye fogged WHO px with normal binocular vision px with no/poor binocular vision early and pre-presbyopes (people with (strabismus, dense amblyopia, monocular accommodation) dense cataract) non-tols to previous prescriptions* presbyopes (no accommodation) Px who are monocular! Much quicker PROs More pleasant for px? Can be easier if inexperienced Better for nystagmus: mvts minimised No risk of ‘interference’ from fellow eye Better for rotational phorias: stability of cyl Better if px gives poor subjective responses axis CONs Can get in a mess if used on incorrect px Takes longer May need to change to monoc. if px reports Need to +1 blur and binocular balance binocular discomfort May need to offer +/- 0.25DS binoc. Add Relies on fairly confident objective result Can dissociate phorias if occluded for long  Cycloplegic Pseudophakes Aphakes Presbyopes* refraction Who gets binocular balancing/refraction? Monocular Deep Very poor VA people! Strabismus amblyopia in one eye Technique 1: Monocular subjective + binocular balance Procedure for monocular refraction. (Follow the red arrows) Retinoscopy Monocular refraction RE Occlude LE Un-occlude LE LE Monocular refraction LE RE LE Binocular balancing BVS X-cyl BVS X-cyl Binocular add Refine sph Refine sph VA VA Record final Rx with final VAs Plus 1 blur Plus 1 blur Occlude RE Un-occlude, BEO Binocular Balance Binocular Add (+0.25DS) Monocular subjective + binocular balance: options With fusional vergence present: Modified Humphriss Humphriss Immediate Contrast Multiple techniques: Polarized chart or duochrome Modified Humphriss Turville Infinity Balance Humphriss Immediate Contrast Polarized chart or duochrome Prism dissociated balance Turville Infinity Balance Without fusional vergence: Prism-dissociated balance Used with phoropters  Relaxing accommodation equally in both eyes Modified Humphriss Humphriss Immediate Contrast Prism Dissociated Balance Blur LE back about 3 lines Same as Modified Humphriss (+0.75/+1.00Ds) Used with phoropter heads BUT: LE Central vision suppressed Intentionally cause vertical Add +0.25DS to RE for 1-2 sec, Attention shifted to ‘active’ RE diplopia then show -0.25DS for HALF Refine RE sphere (max Binocularly fog then de-fog to the time. Remove both and plus/best VA) with both eyes best VA ask 1 or 2? open Can use letters or duochrome Add plus/minus for best VA Swap eyes as a target Must be able to appreciate diplopia Need: equal (ish) VA, binocular status, Beware: phorias/strong ocular dominance  Modified Humphriss: 1. Remove the occluder from the RE and ask the patient to look at the smallest line they can 2. Add +0.25DS and ask “are the letters clearer, the same, or worse with this lens?” If clearer or the same we need to add the plus in +0.25 steps until acuity first blurs = this is our end point for this eye If +0.25 blurs vision we do not add, but proceed to next step: 3. Show -0.25DS and ask “are the letters clearer or do they look smaller and blacker?” 4. If clearer then add the -0.25DS until there is no further improvement in VA = end point If smaller and blacker do not add = end point  RE LE VA 6/6 VA 6/12 with fogging lens End goal of refraction: code:QA-KI-NL =point focus on or just behind retina 9 8 7 6 5 4 3 2 1 0 1 2 3 4 5 6 7 8 9  Procedure for monocular refraction. (Follow the red arrows) After BB→Binocular addition Retinoscopy Occlude LE Un-occlude LE Perform this after binocular balancing RE LE LE Use flippers to offer +0.25DS BVS BVS binocularly X-cyl X-cyl Refine sph Refine sph Binocular addition may not be VA VA necessary as balancing with monocular fogging already relaxes accommodation Plus 1 blur Plus 1 blur But binocular addition can be useful in Occlude RE patients who require maximum plus Un-occlude, BEO such as low hyperopes with near work Binocular Balance symptoms Binocular Add (+0.25DS) Recording your findings Final Distance Refraction RE +2.00 /-1.75 x 70 6/5 LE +1.75 /-1.25 x 95 6/5 Write your results accurately and clearly! Technique 2:Binocular Refraction Retinoscopy Obtain retinoscopy result for both eyes Check VA Fog LE Un-fog LE Fog left eye to about 3 lines (+0.75/+1.00DS) Advise px you are making one eye blurry on purpose, and to let RE LE you know if this starts to bother them. BVS, X-cyl, refine sphere on RE. BVS BVS Check end VA→ fog with +0.75/+1.00DS. Check it blurs back X-cyl X-cyl Remove LE fogging lens BVS, X-cyl, refine Sphere Left. Refine sph Refine sph Check end VA VA VA Remove fogging lenses Allow px to have a few blinks Fog RE Ask: ‘’How does that feel? Any pulling/blurriness?’’ Un-fog RE: BEO Comfort Checks Technique 2:Binocular Refraction Remember to go for most plus with best VA If they report double vision/discomfort, occlude left eye and continue monocularly. Can always do a quick modified Humpriss to correct balance if px reports discomfort. Clinical decision making Clinical Decision Making 1. Some Pxs prefer under-plus or over-minus distance correction 2. Be careful of any change >+0.50 DS: could be over-plussing or patient is latent hyperope: consider cycloplegic refraction. 3. Consider the pupil size, if small, then can easily over-plus because +/-0.25 sphere will make minimal difference to blur circle, so its harder to tell if clearer or not (use ±0.50DS to check if definitely wants the plus) +1.00 test will not blur back as far as 6/18 – so you may think you need more plus 4. Consider increased media opacification and/or poor VA, as this may give apparent increase in depth of focus therefore problems detecting 0.25 change. 5. Consider balance in previous glasses and any relevant H&S Finally if you are not sure about giving the plus, then consider the range of clarity and aim for middle of the range, or drop back from extreme plus result by ~0.25 or 0.50. Case Scenarios: Monocular Miss Jenny Peters, age 24 Patched as a child for RESOT with poor compliance BCVA RE 6/30 LE 6/6 Monocular Retinoscopy result: + Binoc. Bal R+5.50DS L+0.75/-0.25 x 90 You need to check her left eye with +1.00 blur Binocular Case Scenarios: Monocular Mr Paul Venner, age 75 Pseudophakic in both eyes BCVA RE 6/7.6 LE 6/6 Monocular Retinoscopy result: + Binoc. Bal R+0.25/-1.00 x 180 L+0.75/-0.25 x 90 Binocular Case Scenarios: Monocular Mr Abdul Khan, age 30 No significant history BCVA RE 6/6 LE 6/6 Monocular Retinoscopy result: + Binoc. Bal R+1.25/-1.00 x 180 L+1.50/-0.25 x 175 Binocular Case Scenarios: Monocular Ms Sara Kalique, age 37 No significant history, Large exophoria with poor compensation BCVA RE 6/6 LE 6/6 Monocular Retinoscopy result: + Binoc. Bal R-2.00/-1.00 x 180 L-2.50/-0.25 x 175 Binocular The hyperope Children: Adults: Amblyogenic if anisometropic >1.5DS Ability to accommodate decreases with Potentially amblyogenic if isometropia age >+5DS Presbyopia Often occurs with strabismus Previous latency no longer sufficient Low bar for cycloplegia Lack of understanding/tolerance: esp low hyperopic early presbyopes.  code:QA-KI-NL Classification of hyperopia  Total Hyperopia Too weak 0 Too strong No accommodative tone: fully cycloplegic Total hyperopia  Latent Hyperopia code:QA-KI-NL ∞ Total hyperopia 9 8 7 6 5 4 3 2 1 0 1 2 3 4 5 6 7 8 9 Plus Minus correcting correcting lenses lenses Latent hyperopia: DV is clear Due to tonus of ciliary muscle Amount decrease over ∞ time Manifest hyperopia: Any remaining hyperopia NOT accounted for by the tonus of ciliary muscle  Hyperopia with accommodative effort code:QA-KI-NL Facultative ( Accommodative effort): Amount of hyperopia corrected with max accom. (May be all/part) Absolute hyperopia: The hyperopia which cannot be corrected by the accommodative system or ciliary muscle ∞ tonus  code:QA-KI-NL Demonstration  code:QA-KI-NL Dealing with latent hyperopia Control accommodation throughout (ret, subjective) Consider binocular refraction Aim for max ACCEPTED plus May need to cyclo kids Consider tonus if not prescribing for BV Keep an eye on the cover test results May need to gradually increase over time Consider symptoms Think about how to explain to px: immediate and prognosis  code:QA-KI-NL Cyclo When ret reflex is unstable When binocular issue is suspected: esp. esotropia When family history of amblyopia/high plus If vision/VA unequal without refractive cause If unable to co-operate Malingering?  code:QA-KI-NL What drops? 0.5 or1.0% cyclopentolate hydrochloride Max. effect 20-40 mins Recovery up to 12-24 hours Typically 1x1.0 % for >6 months --. Refract after 30 mins Typically 1 x 0.5% for older children Bear in mind this is not true ‘full cycloplegia’ May consider 0.5% proxymetacaine  code:QA-KI-NL Cycloplegic comparison  code:QA-KI-NL Prescribing post-cyclo Are you referring on to HES/orthoptics? Measure VA on collection and 6-8 weeks after collection If strabismus present: full cyclo Otherwise, consider adaptation Reduce rx equally in anisometropia Give information to parents on compliance Recall? Background learning Read lab book section on these topics Moodle resources Prepare for full routine: Revise H&S Revise prelims Revise health Revise management Attendance code: