by John M. Rinehart, OD
LC is a 50-year-old female who came to me for continuation of orthokeratology which she had begun at least 2 years earlier in another state and for the past year with another local OD. Her lenses were worn her waking hours.
DVA with current lenses: 20/20 OD, OS
Unaided DVA: 20/40 OD, OS
OD –0.50 –1.00 x 075 20/20
OS –1.00 00.75 x 120 20/20
OD 44.00/44.75 @ 090 no distortion
OS 43.75/45.00 @ 090 no distortion
Current lenses: OU 8.23 BC +0.75 10.0 diam 7.58 AC
Both lenses positioned superior on the cornea and this is confirmed by the topography above.
- Should this patient be refit now or should she be taken out of lenses so the cornea can normalize and we get a fresh start?
- What fit changes need to be made to improve lens centration?
- Is this patient a candidate for overnight wear?
It was determined that for the convenience of the patient we would refit without making her go without her lenses.
It is necessary to increase the sagittal depth of the lenses in order to improve centration. In this case the lenses were designed approximately 20 microns steeper. This is about 0.08 mm steeper in the alignment curve radius.
Without knowing her original Rx we can only estimate how much more correction change there will be. Our goal is to move her into overnight wear.
Initial Lens Refit:
OU 8.23 BC +0.75 D 10.6 diam 7.50 AC
After one week of waking hours wear
Comfort is great and unaided DVA is “fairly good”
DVA with CL 20/20 OD, OS
Unaided DVA 20/25-1 OD, OS
OD 41.25/41.50 @ 090 no distortion
OS 42.00/42.00 @ 090 slight distortion
Treatment zone appears to be better centered but still slightly high. In light of the fact that the topography improved and it has only been one week of lens wear I did not make any changes. But since she felt her vision was satisfactory her wearing schedule was switched to over-night.
The patient did not return for approximately 2 months. At that time:
Uncorrected DVA OD 20/25 OS 20/20
Topography shows the treatment zone is still slightly superior.
New lenses were ordered with base curve changes of 0.75 D flatter OD and 1.00 D flatter OS. The alignment curve was also steepened by 0.02 mm to increase the sagittal depth. The goal is to induce more refractive change by flattening the base curve and improve centration by steepening the alignment curve.
Two weeks after the new lenses were dispensed.
Unaided DVA OD 20/20 OS 20/20
K-readings OU 41.50/41.50 @ 090 no distortion
Topography shows well centered treatment zones
At her most recent visit (April of 2006)
Unaided DVA 20/20 (lenses have been off 8 hours)
Subjective refraction OU Plano sphere
K-readings OU 41.50/41.75 @ 090 no distortion
Discussion on how this case was handled and what other treatment options could have been employed.
By John M. Rinehart, OD
CS is a 10 year old male whose parents are interested in OrthoK in the hopes of reducing his dependence on spectacles. His general and ocular health are unremarkable.
OD -5.50 – 0.25 x 180 20/20
OS -5.50 sphere 20/20
OU 42.50/43.50 @ 090 no distortion
Unaided DVA OD, OS 20/250
Pre-fit topography OU e value approximately 0.5
Diagnostic lens fitting should the best initial fit was achieved with an alignment curve of OD 7.99, OS 7.89.
Initial base curves OU 8.77, +0.75, 10.6 mm diameter
- Waking hours wear or overnight wear? What are the advantages and disadvantages of each.
- What are realistic expectations for best unaided DVA?
The patient was told to expect to wear the lenses during his waking hours but when he removed the lenses his acuity may be satisfactory for some activities such as swimming and wrestling.
Because of vacations, wrestling camp and lens loss it took almost 2 months to begin a “normal” waking hours wearing schedule. The following information was acquired after his wearing schedule became consistent (waking hours).
Best corrected DVA: OD, OS 20/20
Unaided DVA: OD 20/100, OS 20/50
OD 40.00/43.00 @ 090 #1
OS 40.00/42.00 @ 090 #1
At this time the patient wanted to move to overnight wear. I recommended that he should continue with waking hours wear since his unaided DVA was still not good enough for him to perform in the classroom.
In order to minimize the lateral decentration the lens diameter was increased to 11.0 mm, the balance of the fitting characteristics were not changed.
Over the next several weeks this young man decided, on his own, to switch to overnight wear and to my pleasant surprise he was successful.
Currently he is wearing his lenses overnight, every night.
Unaided DVA: OD 20/20 OS 20/20
OD 39.00/39.00 @ 090
OS 40.25/40,25 @ 090
No distortion OU
In spite of delays caused by lost and damaged lenses, and his busy schedule this patient was able to achieve his goal of wearing his lenses only overnight.
I would never council a patient with this correction to expect to achieve these results but it sure is nice when they are able to surpass expectations.
By Cary M. Herzberg OD, FOAA
17 year old Wf wearing SCLs noticing decreasing vision at distance. Patient swims competetively and finds depth perception off w/o lenses
|Present RX SCL||R +3.00 8.7 Acuvue 20/20|
|L +2.00 8.7 Acuvue 20/20|
|Refraction||OD +3.75 20/20|
|OS +2.50 +.25 x 60 20/20|
|K readings||R 43.75 /44.75 x 90|
|L 43.50/44.25 x 90|
|First fit||R 43.50/+3.50 ortho Plus lenses by Contex|
|L 43.50/+2.50 ortho Plus lenses by contex|
After wearing the lenses nightly patient still exhibited a +1.00 over right eye. Left eye corrected down to Plano. Noted right lens looked flat w/o pooling central
Refit R 44.50/+3.50 ortho Plus lenses from Contex
After wearing this lens still left with residual Rx over right eye though less.
Refit 44.50/+5.00 ortho Plus lens from Contex
Excellent results OU
Contex’s Ortho Plus series makes an excellent modality for correcting even high amounts of Hyperopia. It is not uncommon when correcting a juvenile eye that the practitioner will find the need to correct additional plus. This is often due to spasms of accommodation. I have seen this same phenomenon as I fit young Hyperopes with RGPs and found the additional plus noted on follow up. Cycloplegic examination will alert the practitioner to the need for more plus in the script.
Case 3 Topographies
By Cary M. Herzberg OD, FOAA
Subject: 50 years Old presbyopic WF Wearing mono-vision SCLs
RX: OD +.75-.50 x 15, OS; +.50-.50x 5 2D ADD PRIO 1.25
Acuities Uncorrected: R 20/40, L 20/40
Corrected: R 20/20, L 20/20
W/mono-vision SCL L J3
History: Tear Insufficiency has had plugs inserted with limited success. Unable to wear SCLs enough.
Plan: Fit patient with Contex Ortho Plus lenses with slight mono-vision effect OS
R 43.50/+1.50 10.6 Diameter
L 42.50/ +3.50
Restasis bid OU
Results: Distance 20/20 OU 20/25 OD,OS Near J2
Patient wears lenses overnight. Schedules is adjusted for maximum effect
Aspheric qualities of Hyperopic OK lenses will often exceed your expectations and vision results. Here patient has been able to acquire binocular vision success without mono-visions loss of depth of field. Results may exceed previous success with other modalities. Restasis is very effective in cases of tear insufficiency and should be utilized in these cases over typical lubricant treatments which can exacerbate dry eye cases. Ortho-k is often a more successful method of treatment then conventional daily SCL wear.
Case 4 Topographies