Celia (F/21) came for a regular eye examination, with complaint of always rubbing her eyes.
Vision without glasses
R: 6/6-
L: 6/6- (better eye)
Examination shows:
R: -0.25/-0.25×180 (6/6) (+1.00 blur lens test 6/12-) [R: right dominant eye] R>L
L: PL/-0.25×180 (6/6) (+1.00 blur lens test 6/12-)
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test)
NMD @Distance
small XP, 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: 12 – 14 XP (blue part)
-1.00 Near: 10 – 12 XP (blue part)
+1.00 Near: 14 – 16 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
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
TTN, TTN, TTN, TTN, TTN, 6/10cm, 7/12cm, 5/10cm
(normal value: Break/Recovery in less than 10cm or to the nose, TTN)
NRA (Accommodation analysis – ability to relax accommodation) by plus lens
+1.50
(normal value: +1.50 to +2.50)
PRA (Accommodation analysis – ability to stimulate accommodation) by minus lens
-1.50
(normal value: -1.37 to -3.37)
MEM (Accommodation lag – to measure accommodation response seeing near target)
R: +0.25
L: +0.25
(normal value: +0.25 to +0.75)
Facility (Accommodation facility – ability to change focus: far to near or near to far) by Flipper +/- 2.00
BE: 7 cycle per minit(cpm), difficult with plus lens (1st lens)
R: 7 cycle per minit(cpm), difficult with plus lens(1st lens)
L: 9 cycle per minit(cpm), difficult with plus lens(1st lens)
(normal value: 1 cycle = 2 words read
Monocular or R/L: 6cpm to 16cpm
Binocular or BE-both eyes: 4cpm to 14cpm)
Examination of Fusional Reserves (Convergent/Divergent reserve stamina) by Prism Bar
Near, Base-Out/Convergent, PFV: 10/4
Near, Base-In/Divergent, NFV: 18/14
1 BI OU Near, Base-Out/Convergent, PFV: 10/4
2 BI OU Near, Base-Out/Convergent, PFV: 10/4
(normal value: 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 – Adult Data]
Interpupillary Distance = 6.2cm
Celia has Convergence Insufficiency. We know from these findings: (1) significant exophoria at near, (2) receded NPC & (3) decreased PFV @near. Upon these findings, we prompted whether or not she loses focus on near that she needs to blink2 eyes to focus back, she said yes and she will always rub her eyes to see near clearly again. She has been having this since many years ago.
She has 12-14 exophoria at near, in which her PFV needs to have at least twice (that is about 24) to pull in & balance her exophoric near posture.. but she only has 10. Her PFV is low, we tried with prism BI in both eyes, but it did not increase her PFV. Added minus lens at near can stimulate convergence, but it is not particularly helpful.. only able to bring her exophoria to 10-12 XP.
Remember we mention about our two eye systems, accommodation/focusing & vergence being in support of one another to maintain clear single vision for us. She is using her strong accommodation to supplement her deficient convergence.
We prescribe free space stereogram & she was doing pretty well with it when we were checking her meimei. She reported having headache after doing the eye exercise for a while. Yes, we may experience headache while training the eyes to converge. Follow your pace & lets make small improvement bit by bit. We can do it!
– we will do a vergence facility testing at distance when she comes next visit & to monitor her progress
- We will update meimei, Yan in a separate post