Upon repatriation to the United States in 1973, the pilot underwent a discission on the thickened posterior capsular membrane to remove pieces of Plexiglas from his anterior chamber. He also underwent an iris sphincterectomy on his left eye. However, the iris remained eccentric with a keyhole defect at two o'clock due to peripheral anterior iris synechia near a full thickness corneal leukoma at the wound site. Although both eyes have retained vitreous intraocular foreign bodies, most likely Plexiglas, they have remained quiet and stable.

REHAB NOW AN OPTION

Since it now costs up to $8 million to train a combat-ready pilot, the Air Force will try to visually rehabilitate injured pilots and grant them waivers to return to flying if their visual outcome is adequate. This patient's right eye was 20/15 unaided distance on initial evaluation following his injury and remained 20/20 without correction throughout his flying career. His left eye was originally fit with a PMMA lens and in spite of the significant injuries to this eye, he attained 20/15 acuity with the contact lens. He now wears a Boston IV lens (+11.73D, 42.00 B.C., 9.4 mm Dia.).

The pilot has logged over 1,000 hours of flight while wearing the contact lens and reports that he wears his lens up to 16 hours per day. As with most contact lens-wearing aircrew, this pilot has noted some discomfort from dryness in the 5 to 15 percent relative humidity of the cockpit. He uses rewetting drops once or twice during each flight to relieve this discomfort. He has never had a lens fall out of his eye during flight, although he has experienced a lens displacing off-center.

PILOTS NOT GROUNDED BY APHAKIA

Prior to 1959, USAF aircrew members were permanently disqualified from flying after having cataract surgery. Between 1970 and 1993, 32 aphakic aircrew were followed for contact lens wear by the Ophthalmology Branch at the Aeromedical Consult Service (ACS). Although some aircrew wore both soft and hard contact lenses during their flying careers, more aircrew (26) wore soft contact lenses. The majority of this group were monocular aphakes. However, some binocular aphakes are allowed to fly with contact lenses.

Since contact lenses for aphakia are heavier due to increased center thickness, displaced lenses under high G-force are a concern to the USAF. Among the few aphakes who fly high-performance aircraft, none have reported a lens decentering off the cornea in flight due to high G-force. Most of the aphakic aircrew report their lenses only decenter in flight when they rub their eyes.

The USAF aphakic contact lens-wearing population is decreasing since most cataract surgeries are followed with intraocular lens (IOL) implantation. Between 1979 and 1990, the ACS evaluated 23 military aviators with IOLs. All but one were visually acceptable for flying duties. There are now 44 aviators in the USAF IOL Study Group, 10 of whom have binocular IOLs. The Ophthalmology Branch at the ACS currently recommends unrestricted waivers for aircrew with monocular IOLs and has recommended waivers for aircrew with binocular IOLs, even in high-performance aircraft. CLS

Col. Dennis is chief of the Aerospace Vision Section, Ophthalmology Branch, Armstrong Laboratory, Brooks AFB, Texas. Col. Ivan is chief of the Ophthalmology Branch, Armstrong Laboratory, Brooks AFB, Texas.

SPECTRUM FEB. 1996