| CTRI Number |
CTRI/2025/09/095457 [Registered on: 29/09/2025] Trial Registered Prospectively |
| Last Modified On: |
26/09/2025 |
| Post Graduate Thesis |
Yes |
| Type of Trial |
Interventional |
|
Type of Study
|
Diagnostic
Screening |
| Study Design |
Single Arm Study |
|
Public Title of Study
|
Comparing Two Different Tests to Detect Glaucoma Early in People Who May Have It |
|
Scientific Title of Study
|
Comparative analysis of Nasal Step Threshold versus 24-2 Humphrey Field
Analyser field testing in diagnosis of glaucoma among glaucoma suspects |
| Trial Acronym |
nil |
|
Secondary IDs if Any
|
| Secondary ID |
Identifier |
| NIL |
NIL |
|
|
Details of Principal Investigator or overall Trial Coordinator (multi-center study)
|
| Name |
Dr Dev Charan |
| Designation |
Junior Resident |
| Affiliation |
Department of Ophthalmology, Kasturba Medical College, Manipal |
| Address |
Department of Ophthalmology, Kasturba Medical College Manipal
Tiger Circle Road, Madhav nagar, Eshwar Nagar, Manipal
Udupi
KARNATAKA
576104
India |
| Phone |
8769300859 |
| Fax |
|
| Email |
devcharan19799@gmail.com |
|
Details of Contact Person
Scientific Query
|
| Name |
Dr Neetha K.I.R |
| Designation |
Associate Professor |
| Affiliation |
Department of Ophthalmology, Kasturba Medical College, Manipal |
| Address |
Department of Ophthalmology, Kasturba Medical College Manipal
Tiger Circle Road, Madhav nagar, Eshwar Nagar, Manipal
Udupi
KARNATAKA
576104
India |
| Phone |
9886161979 |
| Fax |
|
| Email |
neetha.kir@manipal.edu |
|
Details of Contact Person
Public Query
|
| Name |
Dr Dev Charan |
| Designation |
Junior Resident |
| Affiliation |
Department of Ophthalmology, Kasturba Medical College, Manipal |
| Address |
Department of Ophthalmology, Kasturba Medical College Manipal
Tiger Circle Road, Madhav nagar, Eshwar Nagar, Manipal
Udupi
KARNATAKA
576104
India |
| Phone |
8769300859 |
| Fax |
|
| Email |
devcharan19799@gmail.com |
|
|
Source of Monetary or Material Support
|
| Department of Ophthalmology, Kasturba Medical College, Manipal, 576104 |
|
|
Primary Sponsor
|
| Name |
Dev Charan |
| Address |
Department of Ophthalmology, Kasturba Medical College, Manipal |
| Type of Sponsor |
Other [Self] |
|
|
Details of Secondary Sponsor
|
| Name |
Address |
| Department of Ophthalmology Kasturba Medical College Manipal |
Tiger Circle Road, Madhav Nagar, Eshwar Nagar, Manipal, Karnataka |
|
|
Countries of Recruitment
|
India |
|
Sites of Study
|
| No of Sites = 1 |
| Name of Principal
Investigator |
Name of Site |
Site Address |
Phone/Fax/Email |
| Dr Neetha KIR |
Kasturba Hospital |
Dept of Ophthalmology, Room number 25, Kasturba Hospital, KMC Manipal, Tiger Circle Road, Madhav Nagar, Eshwar Nagar, Manipal
Udupi
KARNATAKA |
9886161979
neetha.kir@manipal.edu |
|
|
Details of Ethics Committee
|
| No of Ethics Committees= 1 |
| Name of Committee |
Approval Status |
| Kasturba Medical College and Kasturba Hospital Institutional Ethics Committee |
Approved |
|
|
Regulatory Clearance Status from DCGI
|
|
|
Health Condition / Problems Studied
|
| Health Type |
Condition |
| Patients |
(1) ICD-10 Condition: H40||Glaucoma, (2) ICD-10 Condition: H400||Glaucoma suspect, |
|
|
Intervention / Comparator Agent
|
| Type |
Name |
Details |
| Comparator Agent |
24-2 Visual Field Testing on Humphrey Field Analyser (HFA) |
The results of the intervention- ie the results of the NSTT, will be compared to the results of the standard of care for glaucoma suspects: the 24-2 Visual Field Testing on Humphrey Field Analyser (HFA).
The results of the two tests will be compared, and an analysis of the tests respective sensitivity and specificity in picking up glaucoma onset in glaucoma suspects will be done.
Additionally, secondary parameters such as the relative time taken for each test will be calculated. |
| Intervention |
Nasal Step Threshold Visual Field Testing on Humphrey Field Analyser (HFA) |
The intervention in this study is the use of the Nasal Step Threshold Test ie NSTT, which is a testing regime on the Humphrey Field Analyser (HFA), that is not part of the traditional standard of care of evaluation for glaucoma in glaucoma suspects.
The study will have all study participants recieve the traditional standard of care glaucoma evaluation- ie 24 2 testing regime on the HFA, and in addition, in the same sitting, and on the same machine, all patients will recieve the intervention- ie NSTT testing.
Those willing to be part of study will be recruited.
Informed consent will be taken.
BOTH 24-2 and NSST are settings on the HFA machine for Visual Field Testing. They differ in the area of visual field tested. The mechanism and procedure of both tests is otherwise similar.
Participants will ONLY have to pay for routine standard of care testing- i.e., total testing cost for a participant of the study will be the EXACT SAME as that of any glaucoma suspect undergoing routine, standard of care glaucoma evaluation. The additional parameter will NOT be charged to the patient. Patients are NOT being called only for the purpose of the study- willing patients will be recruited as seen in the OPD.
ALL PARTICIPANTS in the study will receive the intervention- i.e., will undergo the additional test.
Once the participant has undergone comprehensive eye evaluation, and their glaucoma workup is complete as per the standard of care, with an additional Nasal Step Threshold Parameter also calculated, the results of the testing will be interpreted by the glaucoma consultant. |
|
|
Inclusion Criteria
|
| Age From |
18.00 Year(s) |
| Age To |
99.00 Year(s) |
| Gender |
Both |
| Details |
1. Age more than 18 years
2. Both genders
3. Disease Condition: Glaucoma suspects. Glaucoma suspects were defined as those with ANY ONE OR MORE of the following features:
-Individuals with elevated intraocular pressure , that is, beyond 21mmHg.
-Individuals with manifest optic disc changes, such as Optic Disc Cupping, Neuroretinal Rim Thinning, or Loss. or retinal nerve fiber layer abnormalities, as seen by standard of care testing.
-Individuals with risk factors such as strong positive family history of glaucoma |
|
| ExclusionCriteria |
| Details |
1. Individuals with unreliable visual field testing results.
2. Those with a best corrected visual acuity worse than 6 by 18.
3. Those not capable of sitting upright.
4. Those with other ocular diseases affecting visual fields, such as retinal detachment, central vein occlusion, diabetic retinopathy or other neuropathies unrelated to the study condition.
5. History of intraocular surgery, other than uncomplicated cataract or glaucoma surgery. |
|
|
Method of Generating Random Sequence
|
Not Applicable |
|
Method of Concealment
|
Not Applicable |
|
Blinding/Masking
|
Not Applicable |
|
Primary Outcome
|
| Outcome |
TimePoints |
| -Sensitivity and Specificity of Nasal Step Threshold Test and 24-2 testing in the diagnosis of Glaucoma among Glaucoma suspects |
Across follow up as advised for glaucoma screening, such as at 3 months, 6 months and 1 year across follow up visits. |
|
|
Secondary Outcome
|
| Outcome |
TimePoints |
-Comparison of nature & absolute number of VF changes (eg step defects) picked up by the two tests
-Descriptive analysis of field changes in both, which can be quantified as a set of testing criteria for Nasal step defects as seen in BOTH 24-2 AND NSTT
-Comparison of time taken for both. |
Across follow up as advised for glaucoma screening, such as at 3 months, 6 months & 1 year across follow up visits. |
|
|
Target Sample Size
|
Total Sample Size="86"
Sample Size from India="86"
Final Enrollment numbers achieved (Total)= "Applicable only for Completed/Terminated trials"
Final Enrollment numbers achieved (India)="Applicable only for Completed/Terminated trials" |
|
Phase of Trial
|
Post Marketing Surveillance |
|
Date of First Enrollment (India)
|
09/10/2025 |
| Date of Study Completion (India) |
Applicable only for Completed/Terminated trials |
| Date of First Enrollment (Global) |
Date Missing |
| Date of Study Completion (Global) |
Applicable only for Completed/Terminated trials |
|
Estimated Duration of Trial
|
Years="2"
Months="0"
Days="0" |
|
Recruitment Status of Trial (Global)
|
Not Applicable |
| Recruitment Status of Trial (India) |
Open to Recruitment |
|
Publication Details
|
N/A |
|
Individual Participant Data (IPD) Sharing Statement
|
Will individual participant data (IPD) be shared publicly (including data dictionaries)?
Response - NO
|
|
Brief Summary
|
TITLE Comparative analysis of Nasal Step Threshold versus 242 Humphrey Field Analyser field testing in diagnosis of glaucoma among glaucoma suspects
INTRODUCTION
Glaucoma is a leading cause of irreversible blindness and is projected to affect 278 million individuals in Asia by 2040 with India bearing a disproportionate burden Despite its prevalence over 75 percent of cases remain undiagnosed due to the insidious nature of progression of visual field loss Early detection of glaucomatous damage is thus critical for preventing blindness but the current goldstandard of glaucoma field testing 242 Humphrey Field Analyzer HFA testing could potentially be overlooking some aspects of glaucomatous field defects including some central defects better seen in 102 testing and potentially early nasal step defects a hallmark of glaucoma due to the tests 6degree grid spacing This could be creating a diagnostic gap and thus delaying treatment initiation allowing preventable vision loss to occur
The Nasal Step Threshold Test NSTT is a test setting present on offers targeted evaluation of the nasal field where early glaucomatous defects frequently manifest While 242 HFA provides broad visual field assessment its spatial resolution may miss localized defects detectable through focused threshold testing Recent studies demonstrate that alternative protocols like 102 testing uncover central defects missed by 242 patterns suggesting similar potential for NSTT in nasal field evaluation However no rigorous comparative studies exist to validate NSTTs diagnostic utility against standard protocols
This prospective crosssectional study addresses this critical knowledge gap by comparing NSTT and 242 HFA in 86 glaucoma suspects from a highvolume tertiary center Participants will undergo both tests in randomized order with sensitivityspecificity analysis defect quantification and timeefficiency comparisons serving as primary outcomes The protocol incorporates rigorous quality controls including standardized diagnostic criteria and randomization to mitigate testingorder bias
By establishing NSTTs diagnostic performance characteristics this research could potentially bring to the forefront a testing sequence till now underexplored and in doing so allow earlier glaucoma diagnoses and create a rapid focused testing protocol particularly valuable in resourceconstrained settings where glaucomas iceberg phenomenon remains most pronounced The studys findings may directly inform clinical guidelines potentially reducing preventable blindness through timely intervention
OBJECTIVES
To determine the sensitivity and specificity of Nasal Step Threshold Test in the detection of glaucoma compared to 242 Humphrey Field Analyser HFA testing
To use or formulate parameters to assess and grade the visual field defects picked up by Nasal Step Threshold Test
To compare the relative time taken for both Nasal Step Threshold Test versus 242 HFA testing
METHODOLOGY
This prospective crosssectional study employs a comparative design to evaluate the diagnostic efficacy of Nasal Step Threshold Testing NSTT against the 242 Humphrey Field Analyzer HFA in glaucoma suspects Below is the detailed methodology
Study Design and Rationale The study adopts a prospective crosssectional design to directly compare NSTT and 242 HFA outcomes within the same patient cohort minimizing intersubject variability This design aligns with diagnostic accuracy studies requiring simultaneous evaluation of multiple tests15
Study Population
Inclusion Criteria
Age more than 18 years both genders
Glaucoma suspects defined by
Intraocular pressure more than 21 mmHg
Optic disc cupping or neuroretinal rim thinning
Family history of glaucoma
Exclusion Criteria
Unreliable visual field tests more than 33 percent fixation loss more than 15 percent false positives
Ocular comorbidities eg diabetic retinopathy optic neuropathies
History of intraocular surgery except uncomplicated cataract or glaucoma surgery
Sample Size and Selection Sample size was calculated to be 86 participants with a 10 percent dropout rate
Data Collection Procedures
Testing Protocol The study is set in the Ophthalmology department of Kasturba Hospital KMC Manipal
Participants are recruited from the available patient population at Ophthalmology department of Kasturba Hospital KMC Manipal after obtaining their informed consent
Patients who are diagnosed to be glaucoma suspects by an ophthalmologist would be advised to undergo standard of care comprehensive eye evaluation and glaucoma testing which includes Visual Field Testing Pachymetry and Fundus photography
Those willing to be part of study will be recruited
Informed consent will be taken
As per the standard of care participants will undergo Visual Field Testing via the Humphrey Field Analyser HFA using 242 HFA testing then in the same sitting and on the same machine an additional parameter the Nasal Step Threshold Test NSST will be calculated
BOTH 242 and NSST are settings on the HFA machine for Visual Field Testing They differ in the area of visual field tested The mechanism and procedure of both tests is otherwise similar
The order of testing will be randomised with all even enrolment numbers undergoing 242 HFA testing first while all odd enrolment numbers would give the Nasal Step Threshold Test first
Participants will ONLY have to pay for routine standard of care testing ie total testing cost for a participant of the study will be the EXACT SAME as that of any glaucoma suspect undergoing routine standard of care glaucoma evaluation The additional parameter will NOT be charged to the patient Patients are NOT being called only for the purpose of the study willing patients will be recruited as seen in the OPD
ALL PARTICIPANTS in the study will receive the intervention ie will undergo the additional test
Once the participant has undergone comprehensive eye evaluation and their glaucoma workup is complete as per the standard of care with an additional Nasal Step Threshold Parameter also calculated the results of the testing will be interpreted by the glaucoma consultant
Variables Collected
Sensitivity specificity of NSTT vs 242 HFA
Defect quantification location depth
Test duration minutes
Quality Control
Standardization
All tests conducted by trained technicians using the same HFA device
Exclusion of unreliable tests based on fixation loss falsepositive thresholds
Bias Mitigation
Data Management and Confidentiality
Patient identifiers replaced with anonymized codes
Data stored in passwordprotected databases with restricted access
Statistical Analysis
Primary Outcomes
Sensitivity specificity analysis using contingency tables
Agreement between tests assessed via Cohens
Secondary Outcomes
Mean test duration compared via paired ttests
Defect severity analyzed using linear regression
Ethical Considerations
Informed Consent Written consent obtained after explaining risks benefits
Compensation Participants receive fruit juice water to mitigate fatiguerelated attrition
Approvals Institutional Ethics Committee approval secured
Justification of Approach
Crosssectional Design Optimal for comparing diagnostic tools without prolonged followup
Randomization Reduces ordereffect bias enhancing internal validity
Power Calculation Ensures adequate sample size to detect clinically meaningful differences
This methodology combines rigorous design standardized protocols and robust statistical planning to address gaps in glaucoma diagnostic practices aligning with funder priorities for translational impact
IMPLICATIONS
This studys findings hold significant theoretical and practical implications for glaucoma diagnosis and public health Theoretically validating the Nasal Step Threshold Test NSTT against the 242 HFA will address critical gaps in understanding early glaucomatous nasal field defects refining pathophysiological models of glaucoma progression By quantifying NSTTs sensitivity specificity the results will clarify its role in detecting localized defects missed by broader protocols advancing perimetry research and diagnostic criteria
Practically confirming NSTTs efficacy could transform clinical protocols enabling earlier glaucoma detection in highburden regions like India where delayed diagnosis drives preventable blindness A rapid focused testing method would optimize resource utilization in tertiary centers and rural clinics alike addressing the iceberg phenomenon of undiagnosed cases The timeefficiency data may streamline workflows reducing patient fatigue and improving compliance during screenings
For policymakers validated NSTT protocols could inform national screening guidelines while device manufacturers might integrate targeted testing algorithms into existing HFA systems By bridging diagnostic disparities this research aligns with global priorities to reduce vision loss offering a scalable model for lowresource settings grappling with glaucomas rising prevalence |