# US 9,872,647 B2 · Detection of early stage alzheimer's disease and mild cognitive impairment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,872,647 B2 - Document ID: US9872647B2 - Status: Granted - Kind: B2 - Application number: 14/844,898 - Filed: 2015-09-03 - Published: 2016-10-20 - Granted: 2018-01-23 - Earliest claimed: 2015-04-17 - Assignees: The Curators of the University of Missouri - Applicants: The Curators of the University of Missouri - Inventors: Peter Koulen - Web page: https://patentgrep.com/patent/US9872647B2 ## CPC - A61B 5/4088: {Diagnosing of monitoring cognitive diseases, e.g. Alzheimer, prion diseases or dementia} - A61B 3/0025: {characterised by electronic signal processing, e.g. eye models} - A61B 3/0091: {Fixation targets for viewing direction} - A61B 3/024: for determining the visual field, e.g. perimeter types - A61B 3/1005: {for measuring distances inside the eye, e.g. thickness of the cornea (A61B3/11 takes precedence)} - A61B 3/102: {for optical coherence tomography [OCT]} - A61B 3/113: for determining or recording eye movement - A61B 3/1225: {using coherent radiation} - A61B 5/1075: {for measuring dimensions by non-invasive methods, e.g. for determining thickness of tissue layer (A61B8/0858 takes precedence)} - A61B 5/7282: {Event detection, e.g. detecting unique waveforms indicative of a medical condition (cough events A61B5/0823; seizures A61B5/4094; sleep apnoea A61B5/4818)} - A61B 5/6821: {Eye} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Systems and methods are described herein for determining that a patient has indications mild cognitive impairment (MCI) or early stage Alzheimer's disease (AD). Microperimetry is used to assess the functional integrity of the patient's retina. Optical Coherence Tomography is used to assess the structural integrity of the patient's retina. Reductions in the size and function of the patient's retina indicate that the patient may have MCI or early stage AD. ## Claims ### Claim 1 A computerized method carried out by at least one server having at least one processor for detection of mild cognitive impairment, the method comprising: measuring a patient's retinal sensitivity by performing a microperimetry procedure to assess the functional integrity of the patient's retina; comparing the retinal sensitivity at a plurality of points within the patient's field of vision with an age matched normal control; determining whether the patient's retinal sensitivity is lower than the age matched normal control, and determining that the patient has indications of mild cognitive impairment and recommending additional neurological evaluation, wherein the patient is determined to have indications of mild cognitive impairment when macular sensitivity of the center of the retina is reduced by at least 20%. ### Claim 2 (depends on 1) The computerized method of claim 1, further comprising measuring the patient's retinal thickness by performing optical coherence tomography to assess the structural integrity of the patient's retina and comparing the retinal thickness at a plurality of points within the patient's field of vision with the age matched normal control. ### Claim 3 (depends on 1) The computerized method of claim 1, further comprising measuring the patient's ability to fixate eye movement and vision on a given pattern and comparing the patient's ability to fixate within a predefined region around the given pattern with an age matched normal control. ### Claim 4 A system for screening a patient for Alzheimer's disease or mild cognitive impairment, the system comprising: a microperimeter; an optical coherence tomographer; a computer having at least one processor, wherein the computer performs the following steps: (A) receiving retinal sensitivity data from the microperimeter, (B) receiving retinal thickness data from the optical coherence tomographer, (C) comparing, with the at least one processor, the retinal sensitivity data and retinal thickness data with age and gender matched control subjects, and (D) based on the comparing, determining, with the at least one processor, whether to diagnose the patient with Alzheimer's Disease or mild cognitive impairment, wherein the determining comprises diagnosing a patient with Alzheimer's Disease or mild cognitive impairment when the retinal sensitivity data shows a reduction in sensitivity in the inner macula compared to the age and gender matched control subjects and the retinal thickness data shows a reduction in thickness of the inner macula compared to the age and gender matched control subjects, and wherein the diagnosing a patient with Alzheimer's Disease or mild cognitive impairment comprises diagnosing the patient with Alzheimer's Disease when the retinal sensitivity data shows a reduction in sensitivity of at least 20% of the inner macula and a reduction in sensitivity of at least 10% of the inferior, temporal, and nasal portions of the retina compared to the age and gender matched control subjects. ### Claim 5 (depends on 4) The system of claim 4, wherein the computer further performs the step of receiving eye movement data from the microperimeter identifying the patient's ability to fixate eye movement and vision on a pattern, and comparing, with the at least one processor, the eye movement fixation pattern data with an age matched control. ### Claim 6 (depends on 5) The system of claim 5, wherein determining further comprises diagnosing a patient with Alzheimer's Disease or mild cognitive impairment when the eye movement fixation pattern data shows a reduction in fixation compared to the age and gender matched control subjects. ### Claim 7 A computerized method carried out by at least one server having at least one processor for determining that the patient has indications of early stage Alzheimer's disease, the method comprising: measuring the patient's retinal sensitivity at a plurality of points by microperimetry; comparing the patient's retinal sensitivity at the plurality of points with that of normal patients; and determining, based on the comparing, the patient has indications of Alzheimer's disease, wherein the determining comprises finding the patient has indications of Alzheimer's Disease when the patient's macular sensitivity of the inner macula is reduced by at least 20% and the patient's macular sensitivity of the inferior, nasal, and temporal portions of the retina are reduced by at least 10% when compared to the normal patients. ### Claim 8 (depends on 7) The computerized method of claim 7, further comprising measuring the patient's retinal thickness at a plurality of points by optical coherence tomography and comparing the patient's retinal thickness at the plurality of points with that of normal patients. ### Claim 9 (depends on 7) The computerized method of claim 7, wherein the normal patients are of the same age and gender as the patient and do not have Alzheimer's disease or mild cognitive impairment. ### Claim 10 (depends on 7) The computerized method of claim 7, wherein determining comprises finding a patient has indications of Alzheimer's Disease or mild cognitive impairment when the patient's retinal sensitivity and retinal thickness are reduced compared to the normal patients. ### Claim 11 (depends on 7) The computerized method of claim 7, further comprising measuring the patient's eye movement to determine a fixation pattern and comparing the patient's fixation pattern with the normal patients. ### Claim 12 (depends on 11) The computerized method of claim 11, wherein determining further comprises finding a patient has indications of mild cognitive impairment or Alzheimer's Disease when the patient's fixation pattern shows a reduction in fixation within two degrees compared to the normal patients. ### Claim 13 (depends on 11) The computerized method of claim 11, wherein the fixation pattern is determined by measuring eye movement using the tracking of blood vessels in the patient's retina.