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PRESCRIBING FOR ASTIGMATISM

OUR CORNEA AND CONTACT LENS RESIDENCY: TOP 5 LESSONS

We recently completed the Cornea and Contact Lens Residency at the Southern California College of Optometry. The program provided a concentrated year of medical and optical management of patients who had complex corneal diseases and irregular astigmatism. Here are the top 5 tips that we learned while caring for this population.

Lessons Learned

  1. Corneal GPs still have a place in managing corneal ectasia. Sclerals have become many practitioners’ preference when managing corneal ectasias. However, there are still several advantages to prescribing corneal GPs. They are less costly for patients, and fewer visits are generally needed to finalize the fit of a corneal GP lens. In addition, the size of corneal lenses allows for easier patient handling and lens care. There is generous tear exchange with each blink, allowing for robust delivery of oxygen to the cornea, which is important considering that these patients often need to wear their lenses during all waking hours. It usually is apparent after one or two trial corneal GPs whether a satisfactory fit can be achieved, so it is worth attempting first before moving onto a scleral.
  2. If you’re not sure what is causing a problem, make a change and see what happens. Lens-related adverse signs can often be caused by more than one reason. For example, limbal staining in scleral lens wear can be from either excessive limbal clearance resulting in limbal edema or from minimal limbal clearance resulting in limbal bearing. If you are unsure of the cause and do not have other methods of confirming the cause (e.g., anterior segment optical coherence tomography imaging for limbal clearance), use your best clinical judgment to make a change to the lens parameters. Depending on whether the signs improve or worsen, you’ll know whether you’re headed in the right direction.
  3. Consultants provide a trove of information. With all of the various contact lens designs available, it can be difficult to understand the subtle nuances of individual lenses. This is where consultants can be your strongest asset in achieving an ideally fitting lens and in troubleshooting issues. The keys are efficient communication of the issue at hand as well as collecting the necessary data to provide the pertinent information to the consultant. An initial multifocal fit will likely need pupil size in dim and bright environments and lid aperture size, while a scleral lens fit will be easier if you provide specific measures of central, midperipheral, and limbal clearance (rather than nonspecific terms such as “excessive” or “good”). A video of the fit is also often beneficial in achieving success with the next lens.
  4. Patients who have a history of corneal transplant need to be seen if something seems awry. If a patient who has a history of a penetrating keratoplasty is complaining of classic symptoms of redness, pain, light sensitivity, or a decrease in vision, he or she should be examined right away to rule out corneal transplant rejection or infection. If the presenting symptoms are slightly more vague—such as a mild irritation, slight fogging of vision, or foreign body sensation—it is easy to dismiss the problem as inconsequential. However, these patients need to be seen right away! The early symptoms of corneal transplant rejection can be very unspecific, but early detection and aggressive treatment are key in saving the transplant. Advise patients to communicate adverse symptoms to their practitioner as soon as they present.
  5. It is so rewarding! Being able to provide quality vision to patients who otherwise function poorly with traditional methods of optical correction is rewarding beyond words. Specialty contact lens fitting can have a steep learning curve, but acquiring the skills to help patients who can benefit is worth it. CLS