A study conducted by the Centre for Vision Research, University of
Sydney, Australia, examines how steroid (corticosteroid) use relates
to risks for cataract,b the clouding of the eye’s lens that leads to
reduced vision and blindness, if untreated.
Many people with asthma
rely on inhaled, and sometimes oral, steroids, as do people with
chronic obstructive pulmonary disease (COPD). This population-based
study, a cohort of the Blue Mountains Eye Study, followed 3,654
Australians, aged 49 years or older, five and 10 years after initial
(baseline) examinations conducted between 1992 and 1994. This
timeframe was needed to assess the long-term impact of steroid use on
cataracts, which develop slowly over years. Based on their findings,
the researchers suggest that more judicious prescription of combined
inhaled and oral steroids may decrease cataract risk for asthma
patients.
“Our findings could mean that combined steroid use, when it results
in high cumulative dosage over relatively long periods, increases
risks for two types of cataract,” said lead researcher, Jie Jin Wang,
MMed, PhD, Centre for Vision Research. “When clinicians prescribe
both steroid forms, the cumulative, combined dose should be
considered. Also, recent clinical trials indicate that combined
steroids are not more effective than inhaled steroids alone in
treating asthma.” He added that further investigation is needed to
determine whether asthma plays a role in nuclear cataract
development.
Elevated cataract risks were found only in patients who, at the time
of their baseline exams, had ever used inhaled steroids, had also used
oral steroids for at least one month, and had no cataracts. Patients
at highest risk for two types of cataract were those defined at
baseline as “current users” of both steroid forms; although this was
a small group, follow up exams found that nearly all of them
developed cataracts. Of seven current user patients, five had used
either steroid form for more than five years, and four of the five
developed posterior subcapsular cataract (PSC). Three additional
current user patients developed nuclear cataracts. In nuclear
cataracts the center of the lens is obscured, and in PSC the cataract
develops in the rear area of the lens. Earlier research had
established a higher risk for PSC in oral steroids users.
April 2009 Issue of Ophthalmology.
About the American Academy of Ophthalmology
AAO is the world’s largest association of eye physicians and surgeons
— Eye M.D.s — with more than 27,000 members worldwide. Eye health
care is provided by the three “O’s” — opticians, optometrists and
ophthalmologists. It is the ophthalmologist, or Eye M.D., who can
treat it all: eye diseases and injuries, and perform eye surgery.
Source
American Academy of Ophthalmology