Treating with tinting
With D.B., testing indicated a preference with the spectrum narrowed to 180 at 30 saturation. Producing the right tint for D.B. required three reference lenses, one from the green set and two from the turquoise set (see Figure 1). This produces an overall 36 percent transmission with a peak at 500 nanometers. The first step was to make a pair of glasses to this specification. The preferred color was then called into the lab (see Figure 2). The lenses still did not provide enough coverage, and he was still experiencing the migraines. We decided to try placing the tint closer to the surface of the eye using contact lenses to more effectively block light.
Using the SoftChrome In-Office Tint System, the lenses were tinted in house. The tinting system kit includes a choice of patterned templates to create pupil and iris combinations, the dyes, tinting equipment, and instructions. The lens used was CooperVision Biomedics XC (omafilcon). A blue tint was applied to the contact lens using the system instructions. A dark tint was required to relieve the migraine symptoms.
It took about five iterations of making the lenses progressively darker before we attained an appropriate transmission level. We poured activator solution (2 ml) into a container and added blue dye (15 drops). The solution was mixed with a syringe and transferred to a vial. The lens was left to tint for 45 minutes. After the time had passed, the lenses were put into a neutralizing solution to restore pH balance to the lens. Then they were transferred to a multi-purpose solution for storage, which was changed several times to be sure no dye was coming out of the lenses.
We tinted only the pupil with the first lenses in order to improve cosmesis. Though these were promising, it turned out that they still did not provide enough coverage. The most successful tint pattern was a full diameter very dark tint (see Figure 3). The result was a profound change in the patient’s life.