DAN polls its members for their personal experiences.
BY DONNA M. UGUCCIONI, DAN RESEARCH,
AND JOEL DOVENBARGER, DAN DIRECTOR OF MEDICAL SERVICES
Good vision is essential to good diving - and for enjoying the underwater environment. For those divers who require vision correction, many options are available to the recreational diver to ensure good vision. However, not all divers are willing to invest in a corrective lens for the faceplate, and others worry about mask flooding and the loss of a contact lens or the consequences of diving at some depths with contacts.
Because of these considerations, some divers have chosen another option - Radial Keratotomy (RK). This is a popular procedure to correct nearsightedness (myopia) by making radial incisions (to a 90-percent depth) in the cornea of the eye. RK has become popular with individuals who have trouble with or cannot wear contact lenses and don't feel that glasses are an acceptable solution.
But what about RK for scuba divers?
"Can I dive after RK surgery?" and "How long should I wait to return to diving?" have become commonly asked questions for DAN medical specialists. In order to gather information about diving with RK and the suggested waiting period after surgery, DAN has asked for the personal experience of DAN members with RK surgery and diving.
This request was published in the September/October 1994 issue of Alert Diver. At that time, DAN membership was over 105,000. DAN received 60 responses to the request through November 1994 and did a follow-up questionnaire with the respondents during the spring of 1995.
The average age of the survey respondent was 40, with an average of 10 years of dive experience. Some had 100 dives or more since surgery. Of the 60 respondents, only nine (15 percent) reported having any problems while diving. Of the 15 percent who had problems, only five divers had an associated mask squeeze, and only one of those had any accompanying eye pain. Two individuals had problems with stinging in their eyes, while one individual had vision change associated at depth.
Eighty-five percent of the respondents reported no problems while diving after RK surgery. In fact, those with no problems commented on how pleased they were with the surgery and how it increased the pleasure of their dive experience. Many had previously worn contact lenses or prescription lenses and enjoyed the freedom of having to wear neither. They also noted they were pleased they didn't have to worry about their masks flooding and the subsequent loss of a contact lens or worry that their expensive prescription lenses might be broken.
Recreational divers thus far have not seen any strong recommendations about diving and RK. Not so for the military. The U.S. Navy has strict regulations regarding RK surgery, and individuals who have had this type of myopia correction have historically been prohibited from diving. Other branches of the service may also limit diving after RK. In a review by Captain Frank Butler, M.D., an eye surgeon and medical diving doctor for the U.S. Navy, several researchers recommended that military divers not be allowed to dive after RK surgery because of the possible complications and the possible barotrauma-induced rupture of the corneal incisions.
On paper Butler has summarized the theoretical data that supports the potential complications and ruptures, but to date no such occurrences have ever been reported. Butler has examined three U.S. Navy divers and one Coast Guard diver who had had bilateral radial keratotomy following completion of their initial dive training. All had returned to diving shortly after undergoing RK surgery. All had been diving for four to 10 years since surgery without any corneal wound problems or other adverse effect.
How long should recreational divers wait to resume diving after RK surgery?
This is a question asked by both divers and their ophthalmologists. Some doctors believe diving should be stopped altogether, while others have a more open approach, but vary in their recommended time intervals until returning to diving.
Like most medical procedures, there are other possible complications and side effects after RK surgery.
These include:
- corneal weakness due to the incisions
- a perceived halo or glare around lights at night
- farsightedness
- the possibility of a corneal rupture with trauma to the eye
Because there is little available data on the subject, many physicians are unsure of recommending a specific waiting period for divers. Most physicians do feel, however, that once there is no risk of infection and the corneal incision sites have healed, diving may be considered.
The Butler review recommended that individuals who have had RK surgery that doesn't involve full-thickness incisions may return to diving after three months. The major risk for damage after surgery would be from direct pressure to an incision site where some weakness might exist. The difference of opinion about when to return to diving is most likely to be based on the physician's experience of when a corneal incision is considered completely healed.
There are no published guidelines on the time required for wound healing prior to resuming diving. The recommendations of ophthalmologists from the DAN study can be seen in Table 1. Some doctors (23.3 percent) made no recommendations on return to diving. The majority of doctors' recommendations allowed diving within five months of surgery, while others recommended waiting at least one year.
According to the survey, most divers seemed to wait up to two months after the operation to resume diving. Only 16 percent of the divers surveyed waited longer than one year. The length of time a diver waited after RK surgery can be seen in Table 2.
In diving, the increase in pressure across the cornea is usually not significant except in the case of a face mask squeeze. Mask squeezes are uncommon in diving. To avoid a mask squeeze, all divers need to do is exhale into the mask to equalize the pressure. While there is a great concern for a potential corneal rupture when diving following RK surgery, its occurrence is uncommon. Most ruptures occur from a direct, blunt blow to the eye.
Conclusions
The decision to have radial keratotomy may differ among individuals and physicians. DAN does not recommend RK surgery, but it is clear from the DAN survey results that some divers are successfully participating in scuba diving with increased enjoyment and limited difficulty. Although there is some concern for a potential corneal rupture when diving following RK surgery, an actual occurrence to date is uncommon.
The options to invest in corrective lenses for a facemask or wear contact lenses, especially disposable ones, are still choices for those who do not consider surgery an option.
Physicians and anyone else who would like more information on the effects of diving after eye surgery and on disorders of the eye may wish to review the article "Diving and Hyperbaric Ophthalmology," by Captain Frank Butler, M.D, in the March/April 1995 issue of Survey of Ophthalmology.
The authors thank Captain Frank Butler, M.D., Christopher Debacker, M.D. and Dr. Gary S. Gerber for their invaluable assistance.
Doctors' recommendation for safe return to diving after RK surgery
Time Interval Total Percentage
0-1 month 19 31.7
2-5 months 17 28.3
5-10 months 8 13.3
Until healed 1 1.7
No recommendation 14 23.3
Blank 1 1.7
TOTALS 60 100.0
How long divers wait to return to diving after RK surgery
Time Interval Total Percentage
0-2 months 28 46.7
3-5 months 9 15.0
6-8 months 12 20.0
9-11 months 1 1.7
12 months or longer 10 16.7
TOTALS 60 100.1
From the MediClip Color Anatomy Collection,1996, Williams & Wilkins, a Waverley Company
