Development and validation of an improved neurological hemifield test to identify chiasmal and postchiasmal lesions by automated perimetry.
OBJECTIVE
To improve the neurological hemifield test (NHT) using visual field data from both eyes to detect and classify visual field loss caused by chiasmal or postchiasmal lesions.


METHODS
Visual field and clinical data for 633 patients were divided into a training set (474 cases) and a validation set (159 cases). Each set had equal numbers of neurological, glaucoma, or glaucoma suspect cases, matched for age and for mean deviation between neurological and glaucoma cases. NHT scores as previously described and a new NHT laterality score were calculated. The ability of these scores to distinguish neurological from other fields was assessed with receiver operating characteristic (ROC) analysis. Three machine classifier algorithms were also evaluated: decision tree, random forest, and least absolute shrinkage and selection operator (LASSO). We also evaluated the ability of NHT to identify the type of neurological field defect (homonymous or bitemporal).


RESULTS
The area under the ROC curve (AUC) for the maximum NHT score was 0.92 (confidence interval [CI]: 0.87, 0.97). Using NHT laterality scores from each eye combined with the sum of NHT scores, the AUC improved to 0.93 (CI: 0.88, 0.98). The largest AUC for machine learning algorithms was for the LASSO method (0.96, CI: 0.92, 0.99). The NHT scores identified the type of neurological defect in 96% (158/164) of patients.


CONCLUSIONS
The new NHT distinguished neurological field defects from those of glaucoma and glaucoma suspects, providing accurate categorization of defect type. Its implementation may identify unsuspected neurological disease in clinical visual field testing.
Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.
Allison N
AN
McCoy
Harry A
HA
Quigley
Jiangxia
J
Wang
Neil R
NR
Miller
Prem S
PS
Subramanian
Pradeep Y
PY
Ramulu
Michael V
MV
Boland
D000465:Algorithms; D019540:Area Under Curve; D005189:False Positive Reactions; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis*; D009897:Optic Chiasm / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields
algorithm; bitemporal; chiasm; glaucoma; homonymous; neuro-ophthalmology; neurological disease; visual field