Keratoconus Newsletter

Courtesy of Drs. Carl Garbus, Cecilia Perez and June Chiang

The purpose of this newsletter is to keep you current with the latest information on keratoconus and to provide you with helpful hints to better serve your patients.  The following optometrists have collaborated on this newsletter: Carl Garbus, Cecilia Perez and June Chiang.  We encourage questions regarding keratoconic cases you have that we can discuss over email and offer some suggestions. Some of the cases may be interesting to the rest of the doctors in the group and would be good cases to publish in the newsletter.  This is our first newsletter, and we will periodically be sending out more newsletters to supplement your practices. We look forward to hearing from you.  

New lens designs are very helpful in keratoconus fitting

New innovative contact lenses help not only improve vision but increase the

comfort levels of wearing as well.  Leading the pack are the following:

Large Diameter Specialty lens

 Dyna Intra-Limbal

The lens is manufactured by Lens Dynamics. Patients with globus

keratoconus, oval keratoconus or pellucid corneal marginal degeneration

and corneal transplants can be successfully fit. It should not be used with central nipple cones. The fitting set comes in the following parameters: 11.2 mm diameter and 9.4 mm optical zone. Special designs are available to customize the lens, such as changing the peripheral geometry.

 GBL

This lens is manufactured by Concise. The lens can be custom ordered with the parameters of your choice. Diagnostic fitting sets are 11.2 mm in diameter with an optical zone of 8.8 mm. Just like the Dyna Intra-limbal set design, this lens can be used for globus keratoconus, oval keratoconus, some pellucid corneal marginal degeneration and corneal transplants.

MORE New Lens Designs

Interpalpebral specialty gas permeable lenses:

 Rose K 2

The original Rose K lens worked well with central nipple cones. With these small diameter lenses and small optical zones, the patients are often aware of ghosting and halos.  Their new design incorporates  an aspheric geometry that reduces some of these untoward effects.  This can be a significant improvement, especially in the higher powers over –8.00.  You can still use your original Rose K fitting sets to fit the new design.

 Keratoconus soft lens:

Hydrocone

This lens was developed by Innovations in Sight and does work with patients who have moderate to severe keratoconus. To fit this lens, you need to purchase a fitting set from the company and use the trial lens set  to determine the base curve and toric power that is necessary for your patient. The fitting set consists of 8 lenses of varying base curves that provides for a range of cone types. It also works well on corneal ectasias following refractive surgery. The lenses are usually considered after the patient is unsuccessful with gas permeable designs. There is a learning curve to fitting keratoconus soft lenses.

Keratoconus Management Pearls

l. Have a number of different fitting sets available in your office so that you can handle the majority of cases that come your way.  We suggest the following sets:

For central cones:

Dyna Z- Cone or the Rose K 2 set

McGuire Cone design

For oval cones:

GBL or Dyna Intra-limbal

For globus cones

GBL or Dyna Intra-limbal

MacroLens, or Jupiter lens

2. To improve comfort and reduce eye rubbing consider prescribing an NSAID like Acular or Acular PF.  This can be dosed bid, before and after contact lens wear.  It is prescribed off label. Be sure to watch your patient carefully for any corneal changes and if there is discontinue the medication. When the patient has more severe allergies use Patanol bid, before and after contact lens wear.

3. Punctal occlusion is a great adjunct for keratoconus patients to help with extra tear volume.

4. The ideal edge lift for interpalbebral lenses is that the band width at the edge of the lens should be .6 mm to .8 mm.  If you have excessive edge lift the patient will be uncomfortable.  Minimize the edge lift by steepening the peripheral system.

5. Always use anesthetic in the contact lens evaluation for new patients and patients who are sensitive.  It is a great adjunct to help with your diagnostic evaluation.

Contact lens problems that you need to avoid:

l. The lens is fit too flat centrally. When you remove the contact lens you observe            swirl staining or central punctate staining.

Tip: constant epithelial breakdown can be avoided by refitting the patient

with a steeper design and/or piggybacking.

2. Protein build-up on the inside curves of the gas permeable lens.

Tip: the patient needs to use weekly enzyme cleaning and the lenses may need to be polished every six months. Those patients, who still build-up protein despite the enzyme cleaning, should replace their gas permeable lenses every six months.

3. Gas permeable lens overwear with patient symptoms, i.e. discomfort.

Tip: try to prescribe a pair of glasses, so the patient can cut down their wearing time while at home. Even if the patient has poor vision with one eye and 20/40 in the better eye with glasses, this may be adequate for use at home.  Also, consider fitting the patient with a keratoconus soft lens for part time use.

4. Educate your patients about eye rubbing. The younger keratoconus patients are more susceptible to corneal thinning and scarring, when they rub their eyes. 

Tip: Treat the patient with cold compresses and Patanol.

Dr. Cecilia Perez, Dr. Carl Garbus and Dr. June Chiang practice in Downtown Los Angeles in the SBC building at 1149 So. Hill St., Ste 115, LA 90015

Dr. Carl Garbus also practices at: FAMILY VISION CARE OPTOMETRY at 28089 Smyth Dr., Valencia, CA 91355

If you have questions regarding your keratoconus patients, please feel free to call Dr. Carl Garbus or Dr. Cecilia Perez at 213-749-3461 or 661-775-1860.

Our email address is cgarbusod@yahoo.com.  We are always ready to help. For the next newsletter, please email us with questions or cases that you would like us to address. One of the topics will be fitting mini-scleral lenses. 

Note: if you send in a case to us please provide as much information as possible.  Giving us the full picture will enable us to be more helpful.