Accuracy and implications of a reported family history of glaucoma: experience from the Glaucoma Inheritance Study in Tasmania.
OBJECTIVE
To ascertain the prevalence of previously undiagnosed primary open-angle glaucoma (POAG) within 5 large POAG pedigrees and to evaluate the reliability of a reported family history of glaucoma within these pedigrees.


METHODS
The Glaucoma Inheritance Study in Tasmania (GIST) identified several large adult POAG pedigrees. Intraocular pressure (IOP), optic disc stereophotography, and automated perimetry were performed on all adult pedigree members. Participants were classified as normal (IOP <22 mm Hg and normal optic disc and field); glaucoma suspect (normal field, but an IOP >/=22 mm Hg and/or suspicious optic disc); or POAG (field defect and glaucomatous optic disc). Some individuals with POAG had been previously diagnosed by their local ophthalmologist; others were diagnosed as a result of the GIST project. Family members with a prior diagnosis of POAG were asked to report if they were aware of any relatives with POAG. This reported family history was then directly compared with the actual pedigree (before the diagnosis of new cases) to calculate agreement.


METHODS
The rate of glaucoma in pedigrees and percentage of previously diagnosed glaucoma cases who were aware of the positive family history of POAG.


RESULTS
Four hundred forty-two subjects (mean age, 54 years [range, 13-97 years]) from 5 pedigrees were examined: 316 subjects (71%) were normal, 47 (11%) were previously diagnosed with POAG, and 8 (2%) were previously diagnosed glaucoma suspects; 30 cases (7%) of POAG and 41 suspects (9%) were newly diagnosed as a direct result of the GIST examination. Of the 47 previously diagnosed POAG cases, 41 were questioned about their prior knowledge of any family history and 11 (27%) were unaware of their family history of POAG.


CONCLUSIONS
Examination of all adult subjects from POAG families yields new cases. Even in large POAG pedigrees, 27% of previously diagnosed POAG patients were unaware of their positive family history. These findings suggest that a higher percentage of adult POAG may be inherited than hitherto reported. Arch Ophthalmol. 2000;118:900-904
McNaught
A I
AI
Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne St, East Melbourne, 3002 Victoria, Australia.
Allen
J G
JG
Healey
D L
DL
McCartney
P J
PJ
Coote
M A
MA
Wong
T L
TL
Craig
J E
JE
Green
C M
CM
Rait
J L
JL
Mackey
D A
DA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005192:Family Health; D005260:Female; D005828:Genetics, Population; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D015995:Prevalence; D015203:Reproducibility of Results; D013648:Tasmania / Q000453:epidemiology