Case study 1

History

-19 year old, female Chinese 

- (-) Glasses, though slight hyperopic (OD: +0.50/-075 x 180 OS: +0.50/-1.25 x 180)

- (+) CLs: Acuvue Oasys. 5 hours/day, 4times/week. Still satisfied with vision but comfort decrease throughout the day

Reasons for glasses: felt that glasses are heavy and uncomfortable

Complaints:

-Oily tears, does not affect vision. Started 2 weeks ago, only in the morning and felt better after washing the face

Intended wearing schedule: 7 hours / day, 2 times/ week 

Her eye and health condition is unremarkable. 

Preliminary Tests

Entrance VA: 

OD:6/4.5

OS:6/6+2

Keratometry:

                    OD: 7.54mm / 44.75D @165             7.18mm / 47.00D @75

                    OS: 7.56mm / 44.625D      @6            7.11mm / 47.50D   @96

Mire Quality: Clear, no distortion

HVID/VVID: 10/9 (OU)

IPA: 6mm

Anterior Ocular Health Examination:

RE:

LE: 

Unremarkable

Initial lens selection

First, we determine the px's corneal cylinder(if any):

After calculation, with 0.25D = 0.05mm

OD: Around -1.75DC

OS:  -2.25DC

Next, we decide which brand, base curve, diameter and power of the RGP we want to fit on the px's eye.

For the right eye, we decided to fit base curve that is steeper than the flatter K, by 0.15mm

As for the left eye, we decided to fit base curve that is steeper than the flatter K, by 0.15mm. However, we wanted to see what will happen if we fit a slightly flatter base curve than the required one, thus we selected the lens as mentioned below.

OD: Oculus Boston, 7.40mm, 9.30mm, -3.00

OS: Oculus Boston, 7.50mm, 9.30mm, -3.00 

Fit of initial lens

                         RE                                                                                               LE

                                                                      

RE		LE
Complete	Coverage	Complete
1.5mm inf nasal displaced	Centration	1.5mm inf nasal displaced
Fast, 2mm, smooth, vertical , nasal inf apical rotation	Movement	Fast, 2mm, smooth, nasal inf apical rotation
Central pooling, mid-peripheral bearing, 0.7mm edge clearance sup. & inf., 0.3mm temporal, 0.5mm nasal	Others	Slight central pooling, 0.5mm edge clearance, equal all quadrants

                                                                                   

Troubleshoot of initial lens fit

We feel that the RGP lens on the right eyes are slightly steep due to the excess 

central pooling that we found on the eye.

Whereas, the RGP on the left eyes are slightly flat as there is only a faint pooling

 in the middle of the lens.

Thus we felt that we should try to fit a flatter base curve on the right eye and a 

steeper base curve on the left eye.

Choice of Second lens

As stated above, we have to make the necessary changes on the base curve of the

 RGP lens that we are trying to fit on the px's eyes.

OD: Oculus Boston, 7.50mm, 9.30mm, -3.00

OS: Oculus Boston, 7.45mm, 9.30mm, -3.00

Fit of initial lens