RTang (F/10) came for eye examination, with complaint of blurry far vision with existing glasses of 3+ years when she was in standard 1. Last year, she sat at the back of class & she could not copy from whiteboard. She sits at the front row this year, and she can copy now. No headache is reported.
Vision without glasses
R: 6/45
L: guess 6/120
Vision with existing glasses
R: -1.50 (6/15-)
L: -2.25 (6/30-)
Examination shows: (Delay Fogging)
R: -2.25 (6/6) [+1.00 blur lens test: 6/15] [R: right dominant eye] R>L
L: -3.50 (6/6-) [+1.00 blur lens test: 6/15-]
Near: L>R
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test, CT)
NMD @Distance
(alternating CT: upon covering left eye, patient reported the target slides down & to the left .. when covering right eye, the target slides up & to the right)
NMD @Near
(alternating CT: upon covering left eye, patient reported the target goes bigger.. when covering right eye, the target goes smaller)
(normal value: orthophoria/NMD-No Movement Detected or small XP, fast recovery)
EP = Esotropia/Esophoria is misalignment of the eye, eye is deviated inwards
XP = Exotropia/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: 5 EP (yellow part)
Near: 1 EP (yellow part)
+1.00 Near: 0 – 2 XP (blue part)
-1.00 Near: 7 – 9 EP (yellow part)
(normal value: 0-1 EP (yellow part) or 0-3 XP (blue part) @Distance; and 0-6 XP (blue part) @Near)
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
Lower -0.25 OU Distance: 3 EP (yellow part)
Lower -0.50 OU Distance: 3 EP (yellow part)
Lower -0.25 OU + 1 BO OU Distance: 1 EP (yellow part)
Lower -0.25 OU + 1 BD OU Distance: 3 – 5 EP (yellow part)
NRA (Accommodation analysis – ability to relax accommodation) by plus lens
+2.00
(normal value: +1.50 to +2.50)
PRA (Accommodation analysis – ability to stimulate accommodation) by minus lens
PL
(normal value: -1.37 to -3.37)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
TTN, TTN, TTN, TTN
(normal value: Break/Recovery in less than 10cm or to the nose, TTN)
AA (Amplitude Accommodation/Focusing – eye stamina/ability of eye to focus & sustain seeing near clearly) by RAF rule
R: 6 YO, 6 YO, 6 YO (pt reported target is clear @end of RAF rule)
L: 6 YO, 6 YO, 6 YO (pt reported target is clear @end of RAF rule)
(normal value: AA goes according to age; YO=years old)
Facility (Accommodation facility – ability to change focus: far to near or near to far) by Flipper +/- 2.00
BE: 8 cycle per minit(cpm), difficult with minus lens(2nd lens) (no diplopia reported on minus lens)
R: 12 cycle per minit(cpm), difficult with minus lens(1st lens) (right eye sees better than with both eyes)
L: 13 cycle per minit(cpm), difficult with minus lens(1st lens) (left eye sees better than with both eyes)
(normal value: 1 cycle = 2 words read
Monocular or R/L: 6cpm to 16cpm
Binocular or BE-both eyes: 4cpm to 14cpm)
MEM – Monocular Estimation Method (Accommodation lag – to measure accommodation response seeing near target)
R: +1.00
L: +1.00
(normal value: +0.25 to +0.75)
Fusional Reserves (Convergent/Divergent reserve stamina) by Prism Bar
Near, Base-In/Divergent, NFV: x/18/12
Near, Base-Out/Convergent, PFV: x/25/20
Distance, Base-In/Divergent, NFV: x/10/6
Distance, Base-Out/Convergent, PFV: x/18/10
(normal value: Blur/Break/Recovery)
Near, PFV: 10-28/7-21
Near, NFV: 7-19/5-15
Distance, PFV: 4-18/5-9
Distance, NFV: 4-10/2-6
[Scheiman et al – Adult Data]
Vergence Facility – ability to make rapid repetitive vergence changes (by Prism Flipper of 12Base Out & 3Base In)
Near: 4 cpm (double with Base Out, blink3 & single.. then double with Base In, blink3 & single) [diff BI to regain single]
Distance: 7 cpm (double with Base Out, blink3 & single)
(normal value: 1 cycle = 2 times clearing target
Distance: 12-18 cpm
Near: 12-18 cpm)
Interpupillary distance, IPD: 5.4cm
RTang feels more comfortable with 1BD OU @Far.. & she does not like 1BO OU @Far.
Prescribe
R: -2.25
L: -3.50
Add: +1.00
Since NFV @D is fine, we update her power & we will assess her eye posture again in 2months.