Fly Well: A clear picture

Avoid flying in clouds caused by cataracts

May 1, 2013

Sackier

Imagine a thunderous waterfall blocking a cave entrance—clear water turned white by circumstance. This is appropriate imagery for cataract (Latin cataracta, “to dash down”). And down is how aviators feel when hearing “you have cataracts.”

Your eye is amazing—eyelids, lashes, and tears protect against foreign objects, desiccating wind, and the sight of annual inspection bills. Incoming light is focused by the delicate cornea and penetrates the iris, which dictates how much enters this adjustable aperture. The lens further focuses images; surrounding muscles allow shape change, adjusting focus as necessary. Light strikes the retina where specialized cells interpret images, transmitting to your brain. The crystal-clear lens is constructed of specialized cells and if orientation, protein, or water content changes, opacities develop, clouding vision. Age most commonly instigates such changes, but other factors contribute. Smoking, hypertension, and diabetes affect the lens—yet another reason to avoid cigarettes and maintain a healthy diet and weight. Physical or thermal eye trauma and using certain medications may also be a factor, as is chronic exposure to sunlight; pilots may be more susceptible to cataracts, so wear decent sunglasses.

Earliest symptoms include sensing that sight is “not quite right,” such as spectacle wearers constantly cleaning their glasses thinking dirt is impairing their vision. Bright lights may become troublesome and colors might take on a yellowish tinge. Areas of view may be fragmented; a section of the panel, for instance—and, for reading, people may require more light. Regular eye exams make sense and pilots should have this in advance of their AME visit so any issues potentially impacting flying privileges can be dealt with in an orderly manner. However, if symptoms appear suggesting cataracts, have your eyes checked pronto. If both visual fields are impacted, without surgery an airman will receive medical denial. If only one eye is affected, special issuance certification may be possible.

There is evidence that diets rich in lutein (kale, spinach) and zeaxanthin (saffron, berries, peppers, corn) and taking a statin drug may lower cataract risk.

There are no current medical cures; therapy is limited to surgery. First, a full assessment of eye anatomy and function is made to plan the procedure. Under local anesthesia (eyedrops and possible injection), perhaps with a little sedation to squash anxiety, the pupil is dilated with drops. Under microscopic guidance, a tiny cut is made into the eye, possibly by laser; the lens capsule is entered; and a James Bond-like instrument squishes the lens and then sucks it up—medicine’s fancy word for that is phaecoemulsification. Next, an artificial lens is slipped into the capsule and the operation is over, usually within 45 minutes. Post-operative pain is easily controlled with tablets, and eye drops prevent infection and control swelling. An eye patch during sleep is recommended to prevent inadvertent rubbing. Although some precautions are advised for a short while—avoiding windy days, shampoo, and make-up—vision will soon improve. With the most commonly implanted unifocal lenses, most patients will require reading glasses, although by the age cataracts appear (after age 50) the majority would have been using them anyway. Some will additionally require spectacles or contact lenses to perfect distance vision. More expensive implantable multifocal lenses may obviate the need for any further eye correction. If one has cataracts in both eyes, surgery may be performed on one side at a time for a number of reasons. Although frustrating because of the resultant unbalanced vision, the gap usually is only a few weeks.

All operations have potential complications and although uncommon, you need to be aware of them and ask good questions. Some are serious, such as retinal detachment; and others, such as lens capsule thickening, may occur years later. With prompt attention these can be addressed.

Once your vision stabilizes, you must meet the standards for the class of medical required and the surgeon should complete FAA Eye Exam Form 8500-7. This should be presented to the AME at the next medical. If spectacles or contacts are required one has to achieve the necessary standard for “corrected” vision. With multifocal lenses (e.g. Crystalens), a mandatory three-month grounding is imposed until clearance is obtained.

So while a haze around a loved one’s face may be romantic, and piloting in IMC challenging, don’t cloud the issue—fly well and get your peepers checked.

Dr. Jonathan Sackier is an expert in aviation medical concerns and helps members with their needs through the AOPA Pilot Protection Services plan. Email the author at jonathan.sackier@aopa.org.