Method and apparatus for testing for color vision loss

Abstract

A method and apparatus for administering eye tests to identify cone sensitivity loss associated with hereditary and acquired color vision loss which may be used for early detection, progress, treatment, and monitoring of eye conditions, traumatic brain injury, optic neuritis, systemic and neurological diseases including Glaucoma, Retinopathy, Age-Related Macular Degeneration, Multiple Sclerosis, Alzheimer's Disease, and Parkinson's Disease and retinal toxicity. Particularly, the method and apparatus disclosed uses a Cone Contrast Test (CCT) to test individuals for hereditary or acquired color vision loss associated with (a) early signs of potential disease/damage/toxicity in an effort to (i) provide opportunity for treatment, and (ii) prevent permanent eye damage, and (b) monitor progress and treatment of such disease/damage/toxicity. The system comprises a computer system including an input device and a display device, and the accuracy and repeatability of the testing is provided by repeated calibration using a colormeter.

What is claimed is: 
     
         1 . A computerized method for administering a cone contrast (CCT) color vision test to a patient, comprising the steps of:
 (a) displaying a first character in a first color at a first contrast level on a display driven by said computer;   (b) receiving a first input signal from said patient via an input device connected to said computer, where said input signal is indicative of whether said patient recognizes said first character displayed in said first color at said first contrast level;   (c) displaying a second character in said first color at a second contrast level on said display driven by said computer;   (d) receiving a second input signal from said patient via an input device connected to said computer, where said input signal is indicative of whether said patient recognizes said second character displayed in said first color at said second contrast level;   (e) assigning a score to said first and second input signals, said score related to sensitivity of a cone in said patient's eye to said first color at said first and second contrast levels; and,   (f) storing said score in a storage device to track said cone sensitivity over time.   
     
     
         2 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said second contrast level is lower than said first contrast level. 
     
     
         3 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , further comprising the step of displaying said score on a computer display. 
     
     
         4 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , repeating the steps of (a) through (e) of  claim 1  with a second color. 
     
     
         5 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , repeating the steps of (a) through (e) of  claim 1  with a third color. 
     
     
         6 . The computerized method for administering a color vision test in a patient recited in  claim 1 , further comprising the steps of periodically verifying a calibration of said first color and said first contrast level of said first character to be displayed on said display, where said verifying is accomplished by software. 
     
     
         7 . The computerized method for detecting color vision loss in a patient recited in  claim 6 , wherein the step of verifying a calibration is automatic if said calibration fails. 
     
     
         8 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said first color is red. 
     
     
         9 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said first color is green. 
     
     
         10 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said first color is blue. 
     
     
         11 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said cone is an S cone. 
     
     
         12 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said cone is an M cone. 
     
     
         13 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said cone is an L cone. 
     
     
         14 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , further comprising the steps of imposing a limited presentation time for steps (a) and (c). 
     
     
         15 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , further comprising the step of alerting said patient of said CCT if said score indicates significant degradation. 
     
     
         16 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , further comprising the step of generating reports of said score. 
     
     
         17 . The computerized method for detecting color vision loss in a patient recited in  claim 4 , wherein said second color is red. 
     
     
         18 . The computerized method for detecting color vision loss in a patient recited in  claim 4 , wherein said second color is green. 
     
     
         19 . The computerized method for detecting color vision loss in a patient recited in  claim 4 , wherein said second color is blue. 
     
     
         20 . The computerized method for detecting color vision loss in a patient recited in  claim 5 , wherein said third color is red. 
     
     
         21 . The computerized method for detecting color vision loss in a patient recited in  claim 5 , wherein said third color is green. 
     
     
         22 . The computerized method for detecting color vision loss in a patient recited in  claim 5 , wherein said third color is blue. 
     
     
         23 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said first character is a letter. 
     
     
         24 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said first character is a number. 
     
     
         25 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , wherein said first character is a symbol. 
     
     
         26 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , further comprising the step of differentiating said score between hereditary and acquired deficiency. 
     
     
         27 . The computerized method for detecting color vision loss in a patient recited in  claim 1 , further comprising the step of differentiating said score between normal, possible deficiency, mild deficiency, moderate deficiency, and severe deficiency. 
     
     
         28 . An apparatus for administering a cone contrast (CCT) color vision test to a patient, comprising:
 (a) a general purpose computer specially programmed for displaying a first character in a first color at a first contrast level on a display driven by said computer;   (b) means for receiving a first input signal from said patient via an input device connected to said computer, where said input signal is indicative of whether said patient recognizes said first character displayed in said first color at said first contrast level;   (c) means for displaying a second character in said first color at a second contrast level on said display driven by said computer;   (d) means for receiving a second input signal from said patient via an input device connected to said computer, where said input signal is indicative of whether said patient recognizes said second character displayed in said first color at said second contrast level;   (e) means for assigning a score to said first and second input signals, said score related to sensitivity of a cone in said patient's eye to said first color at said first and second contrast levels; and,   (f) means for storing said score in a storage device in communication with said computer to track said cone sensitivity over time.   
     
     
         29 . The apparatus recited in  claim 28 , wherein said second contrast level is lower than said first contrast level. 
     
     
         30 . The apparatus recited in  claim 28 , further comprising means for displaying said score on a computer display. 
     
     
         31 . The apparatus recited in  claim 28 , further comprising means for periodically verifying a calibration of said first color and said first contrast level of said first character to be displayed on said display, where said verifying is accomplished by software. 
     
     
         32 . The apparatus recited in  claim 28 , wherein said means of verifying a calibration is operatively arranged to function automatically if said calibration fails. 
     
     
         33 . The apparatus recited in recited in  claim 28 , wherein said first color is red. 
     
     
         34 . The apparatus recited in  claim 28 , wherein said first color is green. 
     
     
         35 . The apparatus recited in  claim 28 , wherein said first color is blue. 
     
     
         36 . The apparatus recited in  claim 28 , wherein said cone is an S cone. 
     
     
         37 . The apparatus recited in  claim 28 , wherein said cone is an M cone. 
     
     
         38 . The apparatus recited in  claim 28 , wherein said cone is an L cone. 
     
     
         39 . The apparatus recited in  claim 28 , further comprising means for imposing a limited presentation time for displaying said first and second characters. 
     
     
         40 . The apparatus recited in  claim 28 , further comprising means for alerting said patient of said CCT if said score indicates significant degradation. 
     
     
         41 . The apparatus recited in  claim 28 , further comprising means for generating reports of said score. 
     
     
         42 . The apparatus recited in  claim 28 , wherein said first character is a letter. 
     
     
         43 . The apparatus recited in  claim 28 , wherein said first character is a number. 
     
     
         44 . The apparatus recited in  claim 28 , wherein said first character is a symbol. 
     
     
         45 . The apparatus recited in  claim 28 , further comprising means for differentiating said score between hereditary and acquired deficiency. 
     
     
         46 . The apparatus recited in  claim 28 , further comprising means for differentiating said score between normal, possible deficiency, mild deficiency, moderate deficiency, and severe deficiency.