VUITY, 1.25% PILOCARPINE hydrochloride in a proprietary vehicle, was launched by Allergan a little more than 6 months ago. The usual pattern in a new pharmaceutical class launch consists of unrealistic expectations and projections, followed by disappointment bordering on depression when initial expectations are not met, and then a rational adjustment to reality and appropriate positioning and use of the new product.
Vuity is following this classical pattern. Irrational exuberance was so high initially that primary care physicians with little knowledge about the risks, benefits, and alternatives of a miotic eye drop for treating mild-to-moderate presbyopia were handing out prescriptions at social events with no patient counseling and no preoperative eye examination. Some eyecare practitioners (ECPs) were doing the same. It is no wonder that many patients were disappointed with their initial experience with a miotic drop when it did not immediately and permanently cure their presbyopia with a single drop.
Focus on the Patient
We now realize that topical pilocarpine is a prescription drug, not an over-the-counter eye whitener. Patients are best served when they are under the care of an ECP, either an ophthalmologist or optometrist, and undergo a complete eye examination prior to treatment initiation. This eye examination will be virtuous in many ways. First, we will diagnose many other eye maladies in emmetropic presbyopes who never had an eye examination, which will help them to preserve their vision. Second, we will discover preoperative findings, including risk factors for retinal tears or detachments, that will encourage us not to prescribe pilocarpine drops for select patients, such as the male axial myope with peripheral lattice degeneration. Third, we will be able to counsel patients regarding appropriate expectations, enhancing success rates.
I’d like to share a few personal thoughts about what we know and what we should share with the potential patient before initiation of pilocarpine therapy for presbyopia. First, the near improvement is 2 lines for 80% and 3 lines for 50%. Some patients obtain minimal benefit and will be nonresponders. We must counsel our patients that not everyone obtains meaningful near vision improvement and realize that the target patient is the patient who benefits from a +1.00 add. We can easily and quickly show patients what a +1.00 add will do for them with a trial frame, loose lenses, or a pair of +1.00 readers. If it is not enough, we can still offer a therapeutic trial, but we should counsel patients that they may not obtain adequate benefit.
Second, we can tell patients there is a learning curve when using this eye drop. They need to know they will need to use it for a few weeks and try it in different lighting and for different purposes to appreciate all the potential benefits and drawbacks. One drop taken only once in the office or at home is not an adequate therapeutic trial.
Be Aware of Side Effects
Especially important is discussion of the side effects, which start with the well-known browache or headache. Most patients will find this side effect tolerable and of short duration, but some will be very uncomfortable. We have learned after years of experience with pilocarpine that a single aspirin tablet taken 30-60 minutes before a pilocarpine drop is placed can nearly eliminate this undesirable side effect.
There is also some burning and stinging on instillation, which is usually transient. This effect is related to the low pH of the pilocarpine solution. Some patients develop mild hyperemia, which can be mitigated by the secondary placement of an eye whitener like Lumify from Bausch + Lomb. Finally, I like to tell patients that this eye drop is best for moderate-to-high luminance environments. Pilocarpine rarely makes dark night vision better except for the rare patient with nighttime dysphotopsia.
It is also important to share with patients that there are potential adverse events. We have been using pilocarpine in ophthalmology to treat glaucoma, reverse mydriasis, and break some pupillary block cases since it was first discovered by Hardy and Gerard in 1874. Pilocarpine used in higher concentrations, frequently and for long durations, can cause allergies, cataract, iritis, a myopic shift, pupillary block, iris cysts, permanent reduction in dilation, and, most feared of all, posterior vitreous detachment, retinal tear, vitreous hemorrhage, and even retinal detachment. Excess pilocarpine can also induce systemic effects, including nausea, vomiting, diarrhea, diaphoresis, bronchial asthma, and cardiac arrhythmia, in susceptible individuals. Again, this is a prescription drug, and prescription drugs require the engagement of an ECP. They call for a complete eye examination, proper counseling regarding best use, risks, benefits, and alternatives, and appropriate follow up. Ideally, the patient will be captured by an ECP, have access to support for follow up questions, and be followed in the office at appropriate intervals.
There are also several off-label indications for pilocarpine eye drops. Many of us have found pupillary miosis helpful in patients with a complex cornea with irregular astigmatism, including those with prior incisional refractive surgery, such as radial keratotomy, and some early keratoconus patients. Some patients with night dysphotopsia can also be helped. Select patients disappointed with their near vision after a presbyopia-correcting intraocular lens also respond to miotic drops with improved near vision and no loss at distance or intermediate, especially in a high luminance environment.
Weigh the Pros and Cons
Uncorrected presbyopia, much like myopia, hyperopia, and astigmatism, is a significant handicap for many patients. We can of course treat all refractive errors with spectacles, but many patients want to reduce their dependence on glasses, especially for special events. Contact lenses are an alternative for many, but we have all seen many adverse events, some sight threatening, with contact lens use. The same is true for refractive corneal surgery and refractive lens-based surgery.
Contact lenses and refractive surgery are also not risk free. Pilocarpine eye drops provide us with another modality to help the unhappy presbyope who is not satisfied with spectacles in all environments and either not willing or not able to wear contact lenses or undergo refractive surgery. Like contact lenses and refractive surgery, miotic eye drops for presbyopia are not risk free, but they are very low risk. The benefits can be maximized, the risks minimized, and the success rate greatly enhanced by the involvement of an ECP who is interested in presbyopia management and skilled in the art. ■