24/9/2021
SHin (M/10) came for eye examination, mother notices that her son has his face turned sideways to watch TV with existing glasses of 1year.
Vision without glasses
R: 6/30-
L: 6/30-
Vision with existing glasses
R: -0.25/-2.25×170 (6/18)
L: -1.50/-1.00×170 (6/12)
Examination shows:
R: -1.50/-2.25×170 (6/6) [R : dominant right eye]
L: -2.00/-1.75×170 (6/6)
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test)
NMD @Distance
small XP, small then moderate recovery @Near
(normal value: orthophoria/NMD-No Movement Detected or small XP fast recovery)
EP = Esophoria is misalignment of the eye, eye is deviated inwards
XP = Exophoria is misalignment of the eye, eye is deviated outwards
Examination of Eye Alignment (Howell Card)
Distance: 0 – 2 XP
Near: 8 -> 6 <-> 4 XP
+1.00 Near: 8 – 10 XP
-1.00 Near: 0 – 2 XP
(normal value: 0 – 1 EP or 0 – 3 XP @Distance & 0 – 6 XP @Near)
EP = Esophoria is misalignment of the eye, eye is deviated inwards
XP = Exophoria is misalignment of the eye, eye is deviated outwards
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
TTN, TTN, TTN
(normal value: less than 7.5cm or to the nose, TTN)
AA (Accommodation/Focusing – eye stamina/ability of eye to focus & sustain seeing near clearly) by RAF rule
R: 7.5cm, 7.5cm, 7.5cm
L: 7.5cm, 7.5cm, 7.5cm
(normal value: less than 7.5cm for a 10yo or 14D)
NRA (accommodation analysis – ability to relax accommodation)
+2.50
(normal value: +1.50 to +2.50)
PRA (accommodation analysis – ability to stimulate accommodation)
-0.50
(normal value: -1.37 to -3.37)
SHin’s vision with existing glasses is much reduced in one eye, thus he may have turned his face so that he sees TV using the better eye. He shows some exophoria at near, and the exophoria seems to increase with Add power. When prompted whether or not he has sometimes blurry near vision or lose focus at near, he said his near vision is fine. Mother is concerned about myopia progression and SHin is actually open for contact lens in his myopia management. However, due to his exophoria, if he were to choose contact lens.. he may need to do additional vision therapy(eye exercise) or use a separate pair of glasses to better control his exophoria. Alternatively, he may opt for atropine eye drop + Single Vision spectacles or selected myopia control design spectacle lenses in his myopia management. All these myopia control strategies have the efficacy of around >50%.
*Updated
SHin (M/11) came back for follow up. He has been on atropine for a few months now.
We had SHin’s cycloplegic refraction previously.
R: -1.75/-2.25×175 (6/6)
L: -2.50/-1.50×165 (6/6)
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test)
NMD @Distance
small XP, fast to moderate recovery @Near
(normal value: orthophoria/NMD-No Movement Detected or small XP, fast recovery)
EP = Esophoria is misalignment of the eye, eye is deviated inwards
XP = Exophoria is misalignment of the eye, eye is deviated outwards
Examination of Eye Alignment/Posture (Howell Card) by 6^ Base Down on Right eye
Distance: 0 – 2 XP (blue part)
Near: 8 – 10 XP (blue part)
-1.00 Near: 2 – 4 XP (blue part)
(normal value: 0-1 EP or 0-3 XP @Distance; and 0-6 XP @Near)
EP = Esophoria is misalignment of the eye, eye is deviated inwards
XP = Exophoria is misalignment of the eye, eye is deviated outwards
NRA (Accommodation analysis – ability to relax accommodation) by plus lens
+2.25
(normal value: +1.50 to +2.50)
PRA (Accommodation analysis – ability to stimulate accommodation) by minus lens
-0.75
(normal value: -1.37 to -3.37)
MEM – Monocular Estimation Method (Accommodation lag – to measure accommodation response seeing near target)
R: PL (we put +0.50 in front of right eye, still PL)
L: +0.50
(normal value: +0.25 to +0.75)
Accommodation Facility – ability to change focus: far to near or near to far (by Flipper +/- 2.00)
BE: 11 cycle per minit(cpm), difficult with minus lens(2nd lens)
R: 12 cycle per minit(cpm), difficult with plus lens(1st lens) [right eye sees better than with both eyes]
L: 12 cycle per minit(cpm), difficult with minus lens(2nd lens) [both eyes see better with left eye]
(normal value: 1 cycle = 2 words read
Monocular or R/L: 6cpm to 16cpm
Binocular or BE-both eyes: 4cpm to 14cpm)
Fusional Reserves (Convergent/Divergent reserve stamina) by Prism Bar
Near, Base-Out/Convergent, PFV: 2/1
Near, Base-In/Divergent, NFV: 10/6
Distance, Base-Out/Convergent, PFV: 16/12
Distance, Base-In/Divergent, NFV: 10/6
(normal value: Blur/Break/Recovery)
Near, PFV: x/15-31/10-22
Near, NFV: x/7-17/3-11
[Scheiman et al – Children 7-12yo Data]
AA (Amplitude Accommodation/Focusing – eye stamina/ability of eye to focus & sustain seeing near clearly) by RAF rule
R: 13 YO, 13 YO, 15 YO
L: 11 YO, 11 YO, 11 YO
(normal value: AA goes according to age; YO=years old)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
TTN, 6/8cm, 8/10cm, TTN, TTN
(normal value: Break/Recovery in less than 10cm or to the nose, TTN)
Vergence Facility – ability to make rapid repetitive vergence changes (by Prism Flipper of 12Base Out & 3Base In)
Near: 8 cpm (slow to clear Base Out)
Distance: 0 cpm (cannot fuse 12 Base Out)
(normal value: 1 cycle = 2 times clearing target
Distance: 15 cpm
Near: 15 cpm)
Interpupillary Distance = 6.1cm
SHin’s vision is fine seeing far & near. He shows some eye findings of Convergence Insufficiency, CI:
- significant exophoria @Near
- very low PFV @Near
- cannot fuse 12 Base Out @Distance on vergence facility
But his NPC seems fine.. probably his accommodation/focusing is doing the extra work in supporting his CI, to sustain & maintain clear near vision. We ask whether or not he sees blurry near vision especially after long hours of computer/phone, he said his near vision is fine. Mother Winnie shares that he does not see phone.. only use computer during online learning.
We prescribe a simple pencil push up eye exercise since he is asymptomatic/no complaint. Our management really depends on you and your complaint. If you do not have complaint, you would not want to do the eye exercise too. Only if you face difficulty in your vision, will you be motivated to do the eye exercise.