Documentation

Introduction

GLAUC-STRAT Calc is a professional mobile application designed to help ophthalmologists efficiently categorize glaucoma patients according to severity using the GLAUC-STRAT-Fast tool, which implements RCOphth/UKEGS (Royal College of Ophthalmologists / UK & Eire Glaucoma Society) guidance.

Beyond Risk Stratification: Research & Machine Learning

While GLAUC-STRAT Calc implements the GLAUC-STRAT-FAST algorithm for clinical risk stratification, the app extends beyond this core function by collecting comprehensive patient data with user consent. This includes:

• Demographics (age, sex, ethnicity)
• Clinical factors (visual field data, glaucoma type, ophthalmic co-morbidities)
• Systemic and social factors
• Optional anonymized location data (for geographical distribution studies)

This rich dataset supports machine learning research for predicting glaucoma prognosis, enabling development of predictive models for disease progression and treatment outcomes. By participating, clinicians and patients contribute to advancing the understanding of glaucoma and improving care for future patients.

Key Features

• Quick Assessment: Rapid patient categorization in seconds
• QR Code Integration: Patients display their unique QR code for instant identification
• Guideline Compliant: Implements official RCOphth/UKEGS protocols
• Progress Tracking: Monitor patient outcomes over time with charts
• Secure Storage: HIPAA-ready cloud storage via Firebase
• Multi-Platform: Available on iOS and Android devices

Who Should Use This App?

GLAUC-STRAT Calc is designed for:

Healthcare Professionals

• Consultant Ophthalmologists
• Ophthalmology Registrars
• Optometrists working in hospital eye services
• Clinical Fellows in ophthalmology
• Other healthcare professionals involved in glaucoma clinics

Patients

Patients with glaucoma can also use the app to:

• Display their unique QR code during clinic visits for fast identification
• View their assessment history and track their glaucoma severity over time
• Monitor their progress between appointments

Account Setup

Creating Your Account

1. Download the App

   Download GLAUC-STRAT Calc from the Google Play Store or Apple App Store on your mobile device.

2. Open the App

   Launch the application and tap "Register" on the login screen.

3. Enter Your Details

   Provide the following information:

   • First Name
   • Last Name
   • Email Address (professional email recommended)
   • Password (minimum 6 characters)
   • Occupation (select from list: Ophthalmologist, Optometrist, etc.)
4. Accept Terms

   Read and accept the Privacy Policy and Disclaimer. These outline how your data and patient data will be handled.

5. Verify Email

   Check your email inbox for a verification link and click to verify your account.

First Login

Permissions

Upon first login, the app will request the following permissions:

Camera Access

Required: Essential for QR code scanning to quickly identify patients. Without camera access, you'll need to manually enter patient information.

Location Services (Optional)

Optional: Used for research purposes to understand geographical distribution of assessments. You can opt-in or opt-out at any time in Settings. This does NOT affect core functionality.

Initial Setup

After granting permissions, you'll be taken to your home screen. The app provides different experiences based on your role:

For Clinicians

Healthcare professionals (ophthalmologists, optometrists, etc.) will see the main Calculator screen after login. This is where you perform patient assessments.

For Patients

Patients will automatically be taken to the Patient Progress screen after login. Your unique QR code is displayed prominently at the top of this screen - this is what you show to your clinician during appointments for quick identification.

Next Steps

Take a moment to:

• Navigate to Settings (gear icon) to review your profile
• Configure data collection preferences
• Familiarize yourself with the interface

Using the Calculator

Calculator Overview

The GLAUC-STRAT calculator is the core feature of the app. It allows you to assess glaucoma severity by entering clinical data and receiving an immediate severity categorization.

Assessment Components

The calculator considers the following factors:

• Visual Field Mean Deviation (MD): Better eye and worse eye MD values
• Age: Patient age (calculated from date of birth)
• Structural Damage: Presence of optic nerve damage
• Glaucoma Type: Primary open-angle, angle-closure, secondary, etc.
• Treatment Status: Whether patient is on treatment
• Progression: Evidence of disease progression

QR Code Scanning

QR code scanning is the fastest way to retrieve patient information and begin an assessment. Each patient has their own unique QR code generated by the app, which they can display on their device for quick identification.

How to Scan a Patient's QR Code

1. Tap the QR Icon

   From the main calculator screen, tap the QR code scanner icon.

2. Patient Shows Their QR Code

   Ask the patient to open the GLAUC-STRAT Calc app on their device and display their personal QR code.

3. Position the Camera

   Hold your device steady and position the camera so the patient's QR code is clearly visible in the frame.

4. Auto-Scan

   The app will automatically detect and scan the QR code. Patient information will populate instantly, ready for assessment.

Troubleshooting QR Scanning

• Code not scanning: Ensure good lighting and hold the device 10-20cm from the patient's screen
• Wrong patient loads: Verify the QR code displayed is for the intended patient
• Camera not working: Check camera permissions in device settings
• Screen too bright/dim: Adjust the patient's device screen brightness for better scanning

Manual Patient Entry

If QR codes are unavailable or you prefer manual entry, you can input patient information directly.

Required Information

• Patient ID: Unique identifier (hospital number, NHS number, etc.)
• First Name
• Last Name
• Date of Birth: Used to calculate age for assessment
• Gender: Male, Female, or Other

Steps for Manual Entry

1. Tap the manual entry field on the calculator screen
2. Fill in all required patient demographics
3. Verify information is correct
4. Tap "Continue" to proceed to assessment

Running an Assessment

Calculator Sections

The assessment is organized into several sections that appear sequentially as you complete each one. Fill out all required fields carefully:

1. Ethnicity

Select the patient's ethnicity. Multiple selections are allowed if the patient identifies with more than one ethnic background.

2. Age (Years)

Enter the patient's age in years. This is automatically calculated if you entered the patient's date of birth earlier.

3. Sex

Select the patient's sex: Male, Female, Intersex, or Not Stated.

4. Visual Field Mean Deviation

1. Enter the Better Eye MD value (in dB)
2. Enter the Worse Eye MD value (in dB)
3. Values can be positive or negative
4. Ensure values are from recent, reliable visual field tests

5. Glaucoma Type

Select the type of glaucoma diagnosed:

• Primary Open-Angle Glaucoma (POAG)
• Angle-Closure Glaucoma
• Secondary Glaucoma
• Normal Tension Glaucoma (NTG)

6. Systemic / Social Factors

Indicate any relevant systemic or social factors that may affect treatment or follow-up:

• Systemic health conditions (e.g., diabetes, cardiovascular disease)
• Physical or cognitive disability
• Socioeconomic factors
• Transportation difficulties

7. Ophthalmic Co-morbidity

Select any ophthalmic co-morbidities present:

• Other ocular tumour
• Anterior segment disease
• Posterior segment disease (e.g., AMD, diabetic retinopathy)
• Multiple drug reactions or intolerances
• Keratoconus
• Uveitis
• High axial length (>26mm)
• Previous glaucoma surgery

8. Red Flags

Indicate if any red flags are present that require urgent attention or specialist review. Red flags may include signs of rapid progression, extremely high IOP, or other concerning clinical features.

Calculate Results

After completing all sections, tap the "Calculate" button to generate the severity assessment.

Understanding Results

Understanding the RAG Stratification System

GLAUC-STRAT-FAST uses a Red/Amber/Green (RAG) system with nine stratification levels. Each level is displayed as a combination of the MD category (G/A/R), type value (1/2/3), and modifier counts.

Result Format

Results are displayed in the format: [Category][Type] F[Flags] / O[Ophthal] / S[Systemic]

Example: "R3 F2 / O1 / S-" means:

• R3: Red category (advanced disease), Type 3 (high severity glaucoma type)
• F2: 2 red flags present
• O1: 1 ophthalmic co-morbidity
• S-: No systemic/social factors

Green Category (G1-G3) - Lower Risk

• MD Range: 0 to -4 dB (better eye)
• Conditions: Glaucoma suspects, ocular hypertension, early POAG
• Care Pathway: Suitable for virtual clinic monitoring
• Type 1: Glaucoma suspect, untreated OHT
• Type 2: PACG suspect, treated OHT
• Type 3: Early POAG, PAC, secondary OHT

Amber Category (A1-A3) - Moderate Risk

• MD Range: -4 to -8 dB (worse eye), or < -4 dB with angle-threatening disease
• Conditions: Moderate POAG, early-moderate PACG, early secondary glaucoma
• Care Pathway: May be suitable for virtual monitoring or requires face-to-face review
• Type 1: Early SG, early PACG, moderate POAG with fewer drops
• Type 2: Moderate PACG, moderate POAG with more drops
• Type 3: Moderate secondary glaucoma

Red Category (R1-R3) - High Risk

• MD Range: < -8 dB (worse eye)
• Conditions: Advanced glaucoma, progressive disease, surgical cases
• Care Pathway: Requires consultant-led face-to-face clinics
• Type 1: Advanced POAG, advanced PACG
• Type 2: Developmental glaucoma, advanced secondary glaucoma
• Type 3: Progressive glaucoma, surgical glaucoma, advanced with high IOP

Visual Field MD Thresholds

The primary classification is based on mean deviation (MD) of the worse eye:

• Green: 0 to -4 dB
• Amber: -4 to -8 dB
• Red: Less than -8 dB (> 8 dB loss)

Risk Modifiers

Red Flags (F) - Features requiring urgent attention or consultant review:

• > 2 dB visual field change in a single year
• Only eye affected
• Unexplained visual acuity loss
• Current glaucoma drug reaction
• IOP > 40 mmHg
• Neuro-ophthalmic tumour

Ophthalmic Factors (O) - Co-morbidities increasing complexity:

• Orbital/plastic tumour
• Severe anterior or posterior segment disease
• Multiple drop reactions
• Keratoconus/thin cornea
• Uveitis
• Extremes of axial length
• Previous glaucoma surgery

Systemic/Social Factors (S) - Factors affecting care delivery:

• Relevant systemic conditions (diabetes, cardiovascular disease)
• Mental/physical disability
• Socio-economic deprivation
• Transport difficulties

Submitting the Assessment

After reviewing the results:

1. Tap the "Submit" button to store the assessment data
2. The assessment is automatically saved to the patient's record in the cloud
3. Results are immediately available in the patient's assessment history

Patient Management

Accessing Patient Records

To view a patient's assessment history:

1. Navigate to the Patient Progress screen
2. Search for the patient by name or ID
3. Tap on the patient name to view their full record

Patient QR Codes

Each patient has a unique QR code automatically generated by the app, which provides a fast and accurate way to identify patients during clinical visits.

How Patients Access Their QR Code

When patients log into the GLAUC-STRAT Calc app, they are automatically taken to the Patient Progress screen. Their unique QR code is displayed prominently at the top of this screen.

Clinical Workflow with QR Codes

1. Patient arrives for their clinic appointment
2. Patient opens GLAUC-STRAT Calc app on their own device
3. Patient's unique QR code is automatically displayed at the top of their screen
4. Clinician uses their device to scan the patient's QR code
5. Patient information loads instantly on the clinician's device

What's Stored in a Patient Record

• Unique patient QR code for quick identification
• All historical GLAUC-STRAT assessments
• Dates of each assessment
• Severity categorizations over time
• Visual field MD values
• Classification data (glaucoma type, treatment status, etc.)

Progress Tracking

The Progress Tracking feature allows you to visualize how a patient's glaucoma severity has changed over time.

Viewing Progress Charts

1. Open the patient's record from Patient Progress
2. View the timeline chart showing severity categories
3. Review MD value trends over time
4. Identify patterns of stability or progression

Interpreting Trends

• Stable: Consistent severity category and MD values
• Improving: Movement to lower severity category (rare, may indicate treatment response)
• Progressing: Movement to higher severity category or worsening MD values

Data Management

Data Storage

All patient data is securely stored in Firebase Cloud Firestore with the following protections:

• Encrypted data transmission (HTTPS/TLS)
• Encrypted data at rest
• Access controls requiring authentication
• Automatic backups
• HIPAA-ready infrastructure

Data Synchronization

Patient data syncs automatically across devices when you're logged in with the same account. This allows you to access patient records from multiple devices.

Data Deletion

To delete patient data:

1. Navigate to the patient's record
2. Select "Delete Patient Record"
3. Confirm deletion

Clinical Guidelines

RCOphth/UKEGS Guidance

The Royal College of Ophthalmologists (RCOphth) and UK & Eire Glaucoma Society (UKEGS) have published comprehensive guidance on glaucoma management, including patient stratification for resource allocation and follow-up scheduling.

Key Principles

• Risk-Based Care: Patients are stratified by severity and progression risk
• Efficient Resource Use: Low-risk patients can be managed with less frequent visits
• Patient Safety: High-risk patients receive intensive monitoring
• Evidence-Based: Guidelines are based on current research evidence

GLAUC-STRAT-FAST Methodology

The GLAUC-STRAT-FAST algorithm is a comprehensive risk stratification tool that combines objective clinical measures with modifying factors to determine lifetime risk of significant vision loss.

Core Assessment Components

1. Visual Field Mean Deviation (Primary Classifier)

The worse eye MD determines the base category:

• Green (G): 0 to -4 dB loss
• Amber (A): -4 to -8 dB loss
• Red (R): > 8 dB loss (< -8 dB)

The threshold of -8 dB for advanced disease reflects current consensus among global glaucoma specialists, lowered from the previous -12 dB threshold to enable earlier intervention.

2. Glaucoma Type and Severity (Type Value 1-3)

Each category (G/A/R) is subdivided into three types based on glaucoma diagnosis and severity characteristics:

• Type 1: Lower complexity within category (e.g., glaucoma suspect in Green, advanced POAG in Red)
• Type 2: Moderate complexity (e.g., treated OHT in Green, developmental glaucoma in Red)
• Type 3: Higher complexity within category (e.g., early POAG in Green, progressive glaucoma in Red)

3. Risk Modifiers

Additional factors modify the base stratification:

Red Flags (F): Urgent clinical features requiring immediate escalation

• > 2 dB VF change in single year
• Only eye affected
• Unexplained visual acuity loss
• IOP > 40 mmHg
• Drug reactions or neuro-ophthalmic tumours

Plus Factors: Co-morbidities and social factors affecting care complexity

• Ophthalmic (O): Ocular co-morbidities (uveitis, keratoconus, previous surgery, etc.)
• Systemic/Social (S): Health conditions, disabilities, socioeconomic factors, transport needs

Calculation Algorithm

The app calculates a severity score (0-100) using the following formula:

1. Base Score Calculation

   Score = (MD Category Value × Type Value) + (Red Flags × 3) + (Ophthalmic Factors × 3) + (Systemic Factors × 3)

2. Bilateral Advanced Disease Multiplier

   If both eyes have MD > 8 dB loss, score is multiplied by 1.3 to reflect higher risk

3. Normalization and Capping

   Score is normalized to 0-100 scale and capped at 100

Care Pathway Allocation

• R1-R3 + Red Flags: Consultant-led face-to-face clinics (consultant physically present)
• A1-A3: May be suitable for virtual review or supervised care by trained practitioners
• G1-G3: Suitable for virtual clinic monitoring, some G1 patients may be discharged to community

Best Practices

Clinical Use Recommendations

Data Quality

• Use MD values from reliable, recent visual field tests
• Ensure visual fields are performed on properly calibrated equipment
• Consider test reliability indices (fixation losses, false positives/negatives)
• Use consistent testing strategy (e.g., SITA Standard, SITA Fast)

Patient Selection

• Tool is designed for patients with glaucoma-related conditions including suspects, ocular hypertension, and established glaucoma
• Appropriate for primary open-angle glaucoma, angle-closure glaucoma, and secondary glaucoma
• Use clinical judgment for complex cases (e.g., multiple pathologies)
• Validated for use in risk stratifying eyes with ocular hypertension and open angle glaucoma

Follow-Up Planning

• Use GLAUC-STRAT category as one input for follow-up scheduling
• Consider local protocols and resource availability
• Adjust intervals based on individual risk factors
• Document rationale for any deviation from suggested intervals

Documentation

• Record GLAUC-STRAT assessment in patient notes
• Include MD values used for calculation
• Note any clinical factors not captured by the tool
• Document follow-up plan and rationale

Limitations

Clinical Limitations

• Functional Focus Only: The tool primarily relies on visual field MD and may miss structural progression in early disease
• Pattern Type Not Considered: Does not differentiate between central versus peripheral field loss, despite differing functional impacts
• Requires Reliable VF Data: Accurate, reliable MD values are essential - unreliable visual fields compromise the assessment
• Not Predictive: Validation studies show association with treatment escalations but not with rate of VF progression
• Snapshot Assessment: Represents status at time of assessment; does not predict future progression rate
• Population-Based: Algorithm based on consensus and population data; individual variation exists

Technical Limitations

• Internet Required: Cloud sync requires internet connection
• Device Dependent: QR scanning requires functional camera
• Data Entry Errors: Results only as good as the data entered

Validation Status

Post-hoc analysis using the LiGHT trial data showed:

• ✓ Associated with increased monitoring visits
• ✓ Associated with treatment escalations
• ✓ Associated with need for trabeculectomy
• ✗ Did not find association with rate of visual field progression

Further studies are ongoing to validate the tool across diverse populations and clinical settings.

Not Suitable For

• Patients with unreliable or unavailable visual field data
• Assessment of other optic neuropathies (e.g., compressive lesions, NAION)
• IOP measurement or monitoring
• Treatment recommendations (tool only categorizes risk)

Technical Requirements

Supported Platforms

iOS

• Minimum Version: iOS 13.0 or later
• Recommended: iOS 15.0 or later
• Devices: iPhone 6S and newer, iPad Air 2 and newer

Android

• Minimum Version: Android 6.0 (API 23)
• Recommended: Android 10.0 or later
• Devices: Most modern Android phones and tablets

Network Requirements

• Internet Connection: Required for initial setup, data sync, and cloud storage
• Offline Mode: Basic calculator functions work offline; data syncs when connection restored
• Bandwidth: Minimal data usage (~1-5 MB per session)

Storage Requirements

• App Size: Approximately 50-100 MB
• Data Storage: Patient records stored in cloud; minimal local storage used

Permissions Required

• Camera: For QR code scanning (optional but recommended)
• Internet: For cloud sync and data storage
• Location: Optional, for research purposes only

Privacy & Data Security

Data Protection

GLAUC-STRAT Calc takes data protection seriously and implements multiple security measures:

Encryption

• In Transit: All data transmitted using TLS/HTTPS encryption
• At Rest: Patient data encrypted in Firebase Cloud Firestore
• Authentication: Secure Firebase Authentication with password hashing

Access Controls

• Each user can only access their own patient records
• Email verification required before account activation
• Secure password requirements enforced
• Session management with automatic timeout

HIPAA Compliance

The app is built on HIPAA-ready infrastructure (Firebase/Google Cloud). However, full HIPAA compliance requires:

• Signed Business Associate Agreement (BAA) with Google Cloud
• Institutional policies for mobile device use
• User training on data protection
• Device encryption and password protection

Location Data

Location tracking is entirely optional and used only for research purposes:

• Helps understand geographical distribution of assessments
• Data is anonymized and not linked to patient identities
• Can be enabled/disabled at any time in Settings
• Does NOT affect any core functionality

Data Retention

• Patient records retained indefinitely unless manually deleted
• User accounts retained while active
• Account deletion requests honored within 30 days
• Backups retained for disaster recovery purposes

Troubleshooting

Login Issues

Cannot Log In

• Verify email address and password are correct
• Check that email has been verified (check inbox/spam)
• Use "Forgot Password" to reset if needed
• Ensure device has internet connection

Email Not Verified

• Check spam/junk folders for verification email
• Request new verification email from login screen
• Ensure email address was entered correctly during registration
• Contact support if issue persists: support@glaucstrat.com

QR Code Scanning Issues

QR Code Not Scanning

• Check camera permission is granted in device settings
• Ensure good lighting conditions
• Hold device 10-20cm from QR code
• Clean camera lens
• Verify QR code is in correct format for app

Wrong Patient Loads

• Verify you're scanning the correct patient's QR code
• Check QR code generation system is working correctly
• Try manual entry as alternative

Data Sync Issues

Data Not Syncing

• Verify internet connection is active
• Check Firebase service status
• Log out and log back in
• Force quit app and relaunch
• Check device storage is not full

Missing Patient Records

• Ensure logged in with correct account
• Wait for sync to complete (check for sync icon)
• Verify patient was saved successfully
• Check internet connection for cloud sync

App Performance Issues

App Running Slowly

• Close other apps to free up memory
• Restart the device
• Ensure device meets minimum requirements
• Update to latest app version
• Clear app cache (in device settings)

App Crashing

• Update to latest version of app
• Update device operating system
• Restart device
• Uninstall and reinstall app (data will sync from cloud)
• Report crash to support with device details

Getting Help

If you continue to experience issues:

• Email support: support@glaucstrat.com
• Include: Device type, OS version, app version, description of issue
• Screenshots can be helpful for visual issues
• Expected response time: 24-48 hours

Frequently Asked Questions

General Questions

Is GLAUC-STRAT Calc free to use?

Yes, the app is currently free to download and use for all healthcare professionals.

Can I use this app in my NHS clinic?

Yes, but check with your local information governance team to ensure compliance with Trust policies on mobile device use and patient data.

Does the app work offline?

Basic calculator functions work offline, but data sync requires an internet connection. Assessments performed offline will sync when connection is restored.

Can multiple users share one account?

No, each user should have their own account for audit trail and data security purposes.

Clinical Questions

Can I use GLAUC-STRAT for glaucoma suspects?

No, the tool is designed for patients with established glaucoma. It categorizes severity, not diagnostic probability.

What if my patient has unreliable visual fields?

Do not use unreliable VF data. Wait for reliable tests or use clinical judgment. The tool is only as good as the data entered.

How often should I reassess patients?

Follow RCOphth/UKEGS guidance: Low severity 12-24 months, Medium severity 6-12 months, High severity 3-6 months. Adjust based on individual factors.

Can the tool predict progression?

No, GLAUC-STRAT provides a snapshot severity assessment. It does not predict future progression, though it does factor in current evidence of progression.

Technical Questions

What happens to my data if I delete the app?

Patient data is stored in the cloud and remains accessible if you reinstall and log in. To permanently delete data, use the delete function within the app before uninstalling.

Can I export patient data?

Currently, individual patient records can be viewed and shared within the app. Bulk export features may be added in future updates.

Is my patient data backed up?

Yes, Firebase Cloud Firestore provides automatic backups and redundancy. Data is stored across multiple data centers.

Can I access the same data on multiple devices?

Yes, log in with the same account on multiple devices and data will sync automatically.

How do QR codes work in the app?

The app automatically generates a unique QR code for each patient. When patients log into the app, their QR code is automatically displayed at the top of the Patient Progress screen. During clinic visits, patients open the app on their own device to show this QR code. Clinicians scan the patient's QR code from the patient's device using their own device's scanner, and the patient's information loads instantly. Clinicians cannot access patient QR codes directly - only patients can view their own QR code on their personal device.

Privacy Questions

Who can see my patient data?

Only you can access your patient records. Each user account is isolated with secure access controls.

What is location data used for?

Location data (if enabled) is used for research purposes to understand geographical distribution of assessments. It's entirely optional and anonymous.

Is the app HIPAA compliant?

The app uses HIPAA-ready infrastructure (Firebase/Google Cloud). Full compliance requires institutional BAA, policies, and procedures.

Can I request deletion of my account?

Yes, contact support@glaucstrat.com to request account deletion. This will be processed within 30 days.

Support Questions

How do I report a bug?

Email support@glaucstrat.com with a description of the issue, device type, OS version, and steps to reproduce.

How do I suggest a new feature?

We welcome feature suggestions! Email support@glaucstrat.com with your ideas.

Who developed this app?

GLAUC-STRAT Calc was developed by Dr. Chun-Huei Liu, with mentorship and supervision from Prof. Graham Lee and Prof. Peter Shah. The app supports ophthalmologists in implementing RCOphth/UKEGS guidance for efficient glaucoma care.

Will there be updates to the app?

Yes, the app is actively maintained. Updates may include bug fixes, new features, and updated clinical guidelines.