Corneal Biomechanics, Optical Properties and Anterior Segment Structural Features in Patients With Pseudoexfoliation

A Comparative Study of Anterior Segment Structural Features, Biomechanical Behaviour and Optical Properties of the Cornea in Patients With and Without Pseudoexfoliation Syndrome.

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT06731530

Acronym

CorPEX

Enrollment

Registered

2024-12-12

Start date

2024-12-13

Completion date

2025-05-31

Last updated

2024-12-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Biomechanical Parameters, Corneal Densitometry, Pseudoexfoliation Syndrome

Keywords

pseudoexfoliation syndrome, biomechanical parameters, corneal transparency

Brief summary

The purpose of this study is to assess the effect of pseudoexfoliation syndrome on corneal biomechanics, optical clarity of the cornea, and anterior segment structural features.

Detailed description

A case group of patients with pseudoexfoliation syndrome will ungergo examinations to evaluate corneal optical properties (Pentacam-AXL, HD analyzer), biomechanics (Corvis ST) and anterior segment structural features (OCT-A Angiovue, Pentacam-AXL, IOLMaster V.5.4, Topcon SP-1P). The same examinations will be performed on a group of age-matched controls, and the results will be compared. Corneal optical density will be assessed by backscatter measurement (COD, corneal optical density) using Pentacam AXL (Oculus, Wetzlar, Germany). Corneal optical density will also be assessed by forward-scatter measurement (OSI, objective scatter index) using HD Analyzer (Visiometrics, Terassa, Spain, Keeler). The level of agreement between the two optical density indicators (OSI, COD) will be evaluated. Corneal biomechanics measurements will be performed using Corvis Scheimpflug Technology. The main biomechanical parameter of the Corvis ST is DA (deformation amplitude). DA quantifies how the cornea deforms in response to an air puff and helps evaluate corneal stiffness and elasticity. An additional objective is the study of structural parameters of the cornea as well as, more broadly, the anterior segment in pseudoexfoliation syndrome (PEX) patients, aiming to understand and describe the effects of PEX with the highest possible accuracy. Specifically, using the Pentacam-AXL (Oculus, Wetzlar, Germany), the IOLMaster V.5.4 (Carl Zeiss Meditec), the OCT-Angiography Angiovue (Optovue, Inc., Fremont, California, USA), and the specular microscope Topcon SP-1P (Topcon Medical Inc., Tokyo, Japan), a comparative study will be conducted across a range of variables and maps: corneal topographic data, keratometric measurements, curvature radius data, pachymetric data, anterior chamber depth and volume, angle width, axial length, pupil diameter, and endothelial cell density. Some of these data, such as central corneal thickness, can be measured by two of the aforementioned devices. In this case, we will also attempt to evaluate the level of agreement between the two devices.

Interventions

DEVICEHD Analyzer

HD Analyzer (Visiometrics, Terassa, Spain, Keeler)

DEVICECorvis ST

Corvis ST (Oculus, Germany)

DEVICEPentacam-AXL

Pentacam-AXL (Oculus, Wetzlar, Germany)

DEVICEOCT-A Angiovue

OCT-A Angiovue (Optovue, Inc., Fremont, California, USA)

DEVICEIOLMaster V.5.4

IOLMaster V.5.4 (Carl Zeiss., Meditec)

DEVICETopcon SP-1P

Topcon SP-1P (Topcon Medical Inc., Tokyo, Japan)

OTHERBCVA (ETDRS), Slit lamp examination, Goldmann Applanation Tonometry, Fundus examination

BCVA (ETDRS), Slit lamp examination, Goldmann Applanation Tonometry, Fundus Examination

Study design

Observational model

CASE_CONTROL

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Age

60 Years to 80 Years

Healthy volunteers

Yes

Inclusion criteria

* age 60-80 years. * unilateral or bilateral pseudophakia (cataract surgery undergone at Papageorgiou General Hospital, Thessaloniki, Greece). * open anterior chamber angle (grade \> 2, van Herick method).

Exclusion criteria

* History of intraocular surgery other than uncomplicated cataract surgery (phakoemulsification). * Cataract surgery within the last 3 months. * History of ocular trauma. * Use of contact lenses. * Corneal pathology. * Use of anti-VEGF medications. * History of uveitis or active uveitis. * Hypertension (IOP \> 21 mmHg) or glaucoma. * Myopia or hyperopia greater than 3 diopters. * Astigmatism greater than 1.5 diopters. * Posterior capsular opacification grade 2, 3, or 4 based on the EPCO grading scale. * Tear break-up time \<10 sec

Design outcomes

Primary

Measure	Time frame	Description
Corneal optical density assessed by backscatter measurement	Baseline, during examination : approx. 1 hour	Corneal optical density assessed by backscatter measurement (COD, corneal optical density) using Pentacam AXL (Oculus, Wetzlar, Germany)
Corneal optical density assessed by forward-scatter measurement	Baseline, during examination : approx. 1 hour	Corneal optical density assessed by forward-scatter measurement (OSI, objective scatter index) using HD Analyzer (Visiometrics, Terassa, Spain, Keeler)

Secondary

Measure	Time frame	Description
Corneal biomechanics using Corvis Scheimpflug Technology	Baseline, during examination : approx. 1 hour	The main biomechanical parameter of the Corvis ST : DA (deformation amplitude). DA quantifies how the cornea deforms in response to an air puff and helps evaluate corneal stiffness and elasticity.
Optical quality measured by HD-analyzer : Strehl ratio	Baseline, during examination : approx. 1 hour	Specific measurement variable: Total score of Strehl ratio; Value \[no dimension\];
Optical quality measured by HD-analyzer : MTF cut-off	Baseline, during examination : approx. 1 hour	Specific measurement variable: Total score of Modulation transfer function (MTF) cut-off; Value \[c/deg\];
Corneal biomechanics using Corvis Scheimpflug Technology : velocity	Baseline, during examination : approx. 1 hour	Velocity during the first and the second applanation of the cornea, measured using Corvis ST \[m/s\]
Corneal biomechanics using Corvis Scheimpflug Technology : length	Baseline, during examination : approx. 1 hour	First and second applanation length (mm)
Corneal biomechanics using Corvis Scheimpflug Technology : bIOP	Baseline, during examination : approx. 1 hour	Biomechanically corrected IOP (bIOP) (mmHg)

Other

Measure	Time frame	Description
The level of agreement between the two optical density indicators (OSI, COD) after standardization	Baseline, during examination : approx. 1 hour	The level of agreement between the two optical density indicators : objective scatter index (OSI), corneal optical density (COD) after standardization. Value \[no dimension\]
Anterior chamber depth (mm)	Baseline, during examination : approx. 1 hour	Anterior chamber depth (mm)
Endothelial cell density (cells/mm2)	Baseline, during examination : approx. 1 hour	Endothelial cell density (cells/mm2)
Corneal topography (D)	Baseline, during examination : approx. 1 hour	Corneal topography (D)
Anterior chamber volume (mm3)	Baseline, during examination : approx. 1 hour	Anterior chamber volume (mm3)
Anterior chamber angle (°)	Baseline, during examination : approx. 1 hour	Anterior chamber angle (°)
Axial length (mm)	Baseline, during examination : approx. 1 hour	Axial length (mm)
Central corneal thickness (μm)	Baseline, during examination : approx. 1 hour	Central corneal thickness (μm)

Countries

Greece

Contacts

Primary ContactParaskevi Petridou, MD, MSc

evina_petridou@hotmail.com00306985565799

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026