POOR PROGNOSTIC FACTORS IN PATIENTS WITH BIRDSHOT RETINOCHOROIDOPATHY.
OBJECTIVE
To identify prognostic factors for poor visual outcome in patients with birdshot retinochoroidopathy.


METHODS
A case-control study of 98 patients with birdshot retinochoroidopathy (196 eyes) was evaluated with a follow-up period of at least 12 months. After exclusion of glaucoma, optic atrophy, and macular scar, the remaining eligible patients were categorized into two groups: poor visual outcomes and good visual outcomes. Poor visual outcome was defined as less than -6 mean deviation score on Swedish interactive threshold algorithm (SITA) short-wavelength automated perimetry (SWAP) test and abnormality (amplitude or implicit time) of 30 Hz flicker electroretinogram at 4-year follow-up and at the most recent visit for separate analysis. Potential factors between both groups were statistically analyzed by Chi-square test and logistic regression model.


RESULTS
After the aforementioned exclusion, the remaining 77 patients with an average follow-up period of 52 ± 29 months (335 person-years, 36% with follow-up of more than 5 years) were divided into two groups. Sixteen patients were categorized as having poor visual outcome. Univariate analysis identified significant association of abnormal 30 Hz flicker electroretinogram amplitude (P = 0.004), implicit time (P = 0.002), and SITA SWAP mean deviation at the initial visit (P < 0.001) in the poor visual outcome group. Multivariate logistic regression analysis identified only SITA SWAP mean deviation to be associated with poor visual outcome (adjusted odds ratio, 32.50; 95% confidence interval [3.84-275.32]; P = 0.001) at the initial visit. To verify the model validity, an analysis of 42 patients at 4-year follow-up was performed and the outcome was confirmed (adjusted odds ratio, 8.80; 95% confidence interval [1.58-49.16]; P = 0.013).


CONCLUSIONS
Worse SITA SWAP mean deviation at the initial visit is a predictor of poor visual outcome in patients with birdshot retinochoroidopathy, and may serve as a proxy marker for delayed effective steroid sparing therapy in patients with birdshot retinochoroidopathy.
*Massachusetts Eye Research and Surgery Institution, Waltham, Massachusetts; †Ocular Immunology and Uveitis Foundation, Waltham, Massachusetts; ‡Department of Ophthalmology, Faculty of Medicine, Rajavithi Hospital, College of Medicine, Rangsit University, Bangkok, Thailand; §Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand; ¶Department of Epidemiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand; and **Harvard Medical School, Boston, Massachusetts.
Sukhum
S
Silpa-Archa
Joan J
JJ
Lee
Sutasinee
S
Boonsopon
Marisol T
MT
Lizárraga
Janine M
JM
Preble
Dusit
D
Sujirarat
Pranav
P
Patel
C Stephen
CS
Foster
D000328:Adult; D000368:Aged; D000080365:Birdshot Chorioretinopathy; D016022:Case-Control Studies; D002825:Chorioretinitis / Q000175:diagnosis* / Q000503:physiopathology; D004596:Electroretinography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D041623:Tomography, Optical Coherence; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology*; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult