Practice patterns of office-based ophthalmologists were characterized
using data collected from the National Ambulatory Medical Care Survey
(NAMCS) of 1989, a national probability sample survey conducted by the
National Center for Health Statistics. The sample includes off ice vi
sits made between 1989 and 1990 to nonfederally-employed physicians pr
imarily engaged in office-based practice. Over 38 million office-based
patient visits documented in the NAMCS were analyzed. Fifty-two perce
nt of patients (20.4 million) were over 65 years old; 90% (34.9 millio
n) were white, with blacks and Asians accounting for 5% (1.9 million)
and 3% (1.1 million) of visits, respectively. The leading primary diag
noses and professional activity associated with the visits were catara
ct/cataract surgery 23% (8.9 million), disorders of refraction 19.5% (
7.5 million), and glaucoma 13% (4.9 million). Over 40% (16.1 million)
of visits were for visual dysfunction, abnormal appearance, or abnorma
l sensation. Nearly 33% (12.5 million) were related to either a diagno
stic/screening session or some form of treatment. The duration of visi
ts ranged from 6 to 10 minutes (22.9%), 11 to 15 minutes (29.8%), and
31 minutes or longer (6.7%); 74% (28.1 million) of the patients were a
sked to return for a follow-up visit at a specified time, and 13% to r
eturn if needed. The major sources of reimbursement for office visits
were Medicare (41%, 15.6 million); Blue Cross/Blue Shield (13%, 5 mill
ion); and other commercial insurance (15.5%, 5.8 million).