Nthini (F/20) an undergraduate, came for eye examination, with complaint of migraine on left side for 2weeks continuously & burning eyes doing assignment.
Vision without glasses
R: 6/6
L: 6/7.5-
Examination shows: (Delay Fogging)
R: +0.50 (6/6) [+1.00 blur lens test: 6/9+]
L: +0.25 (6/6) [+1.00 blur lens test: 6/7.5-] [L: left dominant eye] L>R
Near: R>L
Other assessments show:
Examination of Eye Alignment/Vergence (Cover Test, CT)
NMD @Distance
(alternating CT: upon covering left eye, patient reported the target stays centre.. when covering right eye, the target goes to her right)
small XP, fast recovery @Near
(alternating CT: upon covering left eye, patient reported the target goes to her left.. when covering right eye, the target goes to her right)
(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: 4 – 6 XP (blue part) blink eyes 2 XP
+1.00 Near: 10 – 12 XP (blue part)
-1.00 Near: 4 – 6 XP (blue part) blink eyes 2 XP
No glasses Near: 4 XP
(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
NRA (Accommodation analysis – ability to relax accommodation) by plus lens
+1.25
(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: +0.25
L: against movement
(normal value: +0.25 to +0.75)
NPC (Convergence – ability of eye to maintain a single clear near image) by RAF rule
18/24cm, 20/26cm, 12/28cm, 20/30cm, 22/32cm
(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: 20 YO, 25 YO, 30 YO (target is blurry @end of RAF rule, only comes into focus starting @30cm)
L: 20 YO, 25 YO, 30 YO (target is blurry @end of RAF rule, only comes into focus starting @28cm)
(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 +/- 1.50
BE: 14 cycle per minit(cpm), difficult with minus lens(2nd lens)
R: 13 cycle per minit(cpm), difficult with minus lens(2nd lens) (both eyes see better than with right eye)
L: 13 cycle per minit(cpm), difficult with minus lens(2nd lens) (both eyes see better than with left eye) (tend to bring target closer & further away to read)
– cannot clear -2.00
(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: x/6/4
Near, Base-In/Divergent, NFV: x/14/6
Distance, Base-Out/Convergent, PFV: x/14/10
Distance, Base-In/Divergent, NFV: x/6/4
(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: 0 cpm (double with Base Out)
Distance: 5 cpm (double with Base Out, blink3 then single)
(normal value: 1 cycle = 2 times clearing target
Distance: 12-18 cpm
Near: 12-18 cpm)
Fusional Reserves (Convergent/Divergent reserve stamina) by Prism Bar (with 2Base In OU)
Near, Base-Out/Convergent, PFV: x/20/18
Near, Base-In/Divergent, NFV: x/18/12
Near vision with 2Base In OU is not preferred
Modified
R: +0.25 1BI (range of clear vision, ROCV is further away to cover laptop vision)
L: +0.25 1BI
Near vision with 1Base In OU is comfortable
Interpupillary distance, IPD = 6.8cm
We prescribe eye exercise, but Nthini feels her eyes are too uncomfortable & she is unable to do it at the moment. She will wear spec to relieve first and we will see her again in 4-8weeks.