Cassandra (F/20) came for eye examination, vision with existing glasses is fine seeing far & near.. but she complains of blurry vision sometimes. She has strong family history of diabetes.. and mummy is concerned.
Vision without glasses
R: guess 6/120
L: cannot guess 6/120
Vision with existing glasses of few years
R: -5.50/-1.25×180 (6/6)
L: -6.50/-1.25×175 (6/6)
Examination shows: (Delay Fogging)
R: -5.50/-1.25×180 (6/6) [+1.00 blur lens test: 6/12]
L: -6.25/-1.25×175 (6/6) [+1.00 blur lens test: 6/12] (L: left dominant eye) L>R
Near: L>R (adding up to +0.75 in right eye, still 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 stays at centre & looks smaller.. when covering right eye, the target goes to her right & looks bigger)
small XP, fast recovery @Near
(alternating CT: upon covering left eye, patient reported the target looks further away.. when covering right eye, the target looks nearer)
(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: 6 – 8 XP (blue part)
+1.00 Near: 10 – 12 XP (blue part)
-1.00 Near: 2 – 4 XP (blue 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
NRA (Accommodation analysis – ability to relax accommodation) by plus lens
+1.00
(normal value: +1.50 to +2.50)
PRA (Accommodation analysis – ability to stimulate accommodation) by minus lens
-0.25 (when we repeated again: -4.00)
(normal value: -1.37 to -3.37)
MEM – Monocular Estimation Method (Accommodation lag – to measure accommodation response seeing near target)
R: +0.50
L: +0.75/+1.00
(normal value: +0.25 to +0.75)
AA (Amplitude Accommodation/Focusing – eye stamina/ability of eye to focus & sustain seeing near clearly) by RAF rule
R: 20 YO, 20 YO, 20 YO
L: 22 YO, 22 YO, 22 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, TTN, TTN, TTN, TTN, TTN
(normal value: Break/Recovery in less than 10cm or to the nose, TTN)
Accommodation Facility – ability to change focus: far to near or near to far (by Flipper +/-2.00)
BE: 5 cycle per minit(cpm), difficult with plus lens(1st lens)
R: 7 cycle per minit(cpm), difficult with minus lens(2nd lens) [both eyes see better than with right eye]
L: 8 cycle per minit(cpm), difficult with minus lens(2nd lens) [both eyes see better than 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: 18/20/16
Near, Base-In/Divergent, NFV: x/20/18
Distance, Base-In/Divergent, NFV: 18/25/20
Distance, Base-Out/Convergent, PFV: x/14/12
(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: 7 cpm (double with Base Out then single)
Distance: 7 cpm (initially double with Base Out then single.. towards the end, no double reported)
(normal value: 1 cycle = 2 times clearing target
Distance: 12-18 cpm
Near: 12-18 cpm)
Amsler Chart
R: all lines are straight
L: all lines are straight
(normal value: lines are straight & no crooked/distorted
Colour Vision
R: normal
L: normal
(normal value: normal)
Interpupillary distance, IPD = 6.3cm
Cassandra would like to wear contact lens now.
Prescribe monthly toric contact lens
R: -5.25/-0.75×180
L: -5.75/-0.75×180
Pt said slightly blurry at far
2nd trial
R: -5.50/-0.75×180
L: -6.00/-0.75×180