An observational study in Cataract and Primary Angle-Closure Glaucoma, sponsored by Nanfang Hospital, Southern Medical University. Recruiting at 1 site in China. Open to participants aged 18 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by Nanfang Hospital, Southern Medical University · Observational
This observational study aims to evaluate ocular anatomical parameters in patients undergoing anterior segment surgery using swept-source optical coherence tomography (SS-OCT).
Anterior segment surgery, including procedures involving the cornea, lens, and other anterior eye structures, may be associated with changes in ocular anatomy. SS-OCT is a non-invasive imaging technique that provides detailed images of the anterior structures of the eye and allows quantitative assessment of ocular anatomical parameters.
Patients undergoing anterior segment surgery at Nanfang Hospital, Southern Medical University, will be included in this study. SS-OCT will be used to assess ocular anatomical parameters, and the collected measurements will be analyzed to characterize anatomical features and explore potential differences among patients undergoing different types of anterior segment surgery.
The findings of this study may improve understanding of ocular anatomical characteristics in patients undergoing anterior segment surgery and provide useful information for clinical assessment and surgical management.
Background The anatomical structures of the anterior segment of the eye play an important role in ocular function and the clinical management of patients undergoing anterior segment surgery. Accurate evaluation of ocular anatomical parameters may provide valuable information for understanding individual anatomical characteristics and supporting clinical assessment.
Swept-source optical coherence tomography (SS-OCT) is a non-invasive imaging technology that enables detailed visualization and quantitative assessment of anterior segment structures. It provides an opportunity to investigate ocular anatomical characteristics in patients undergoing anterior segment surgery.
Study Design and Methods This is a prospective observational study involving patients undergoing anterior segment surgery at Nanfang Hospital, Southern Medical University.
Ocular anatomical parameters will be assessed using SS-OCT. Relevant demographic and clinical information will also be collected to support the evaluation of anatomical characteristics. The collected data will be analyzed to describe the distribution of ocular anatomical parameters and investigate potential differences or associations across relevant patient characteristics.
The study is observational in nature. Surgical treatment decisions will be made according to routine clinical practice rather than assigned by the research protocol.
1,731 studies on the registry are indexed under Cataract; 233 are open to participants now.
This study's planned enrollment of 500 is above the median of 82 across 493 observational studies indexed under Cataract.
Browse Cataract studies →Nanfang Hospital, Southern Medical University is the lead sponsor of 489 studies on the registry; 213 are open to participants now.
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The study population will consist of adult patients aged 18 to 89 years who are scheduled to undergo anterior segment surgery at Nanfang Hospital, Southern Medical University. Eligible patients include those diagnosed with cataract, primary angle-closure disease, glaucoma with cataract, or other anterior segment disorders requiring surgical treatment. Surgical procedures may include phacoemulsification with intraocular lens implantation, goniosynechialysis, ab interno trabeculotomy, and related combined procedures. Treatment decisions will be made according to routine clinical practice. Approximately 500 participants will be enrolled in this prospective observational study.
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Exclusion Criteria:
Patients undergoing anterior segment surgery will be enrolled in this observational study. Ocular anatomical parameters will be assessed using swept-source optical coherence tomography (SS-OCT). Surgical treatment will be determined according to routine clinical practice, without assignment of treatment interventions by the study protocol.
Diagnostic Test: Ocular anatomical parameters will be measured using a swept-source optical coherence tomography (SS-OCT) device (CASIA2; Tomey Corporation, Nagoya, Japan). The imaging examination will be used to asse
Ocular anatomical parameters will be assessed using a swept-source optical coherence tomography (SS-OCT) device (CASIA2; Tomey Corporation, Nagoya, Japan). This non-invasive imaging examination provides detailed visualization and quantitative measurements of anterior segment structures. The collected imaging data will be used to evaluate ocular anatomical characteristics and investigate their associations with relevant clinical factors in patients undergoing anterior segment surgery. Surgical treatment decisions will follow routine clinical practice and will not be assigned by the study protocol.
Also known as: CASIA2
Change in Anterior Chamber Depth (ACD)
Anterior chamber depth (ACD), defined as the distance from the posterior corneal surface to the anterior lens surface along the visual axis, will be measured in millimeters (mm) using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). Changes from the preoperative baseline will be calculated at each postoperative follow-up visit.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Change in Anterior Chamber Width (ACW)
Anterior chamber width (ACW), defined as the distance between the nasal and temporal scleral spurs, will be measured in millimeters (mm) using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). Changes from the preoperative baseline will be calculated at each postoperative follow-up visit.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Change in Anterior Chamber Volume (ACV)
Anterior chamber volume (ACV) will be quantified in cubic millimeters (mm³) using the anterior chamber analysis function of swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). Changes from the preoperative baseline will be calculated at each postoperative follow-up visit.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Change in Angle Opening Distance at 500 μm (AOD500)
Angle opening distance at 500 μm (AOD500) will be measured in millimeters (mm) using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). AOD500 is defined as the distance between the corneal endothelium and the anterior iris surface along a line perpendicular to the trabecular meshwork at 500 μm from the scleral spur. Changes from the preoperative baseline will be calculated at each postoperative follow-up visit.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Change in Trabecular-Iris Space Area at 500 μm (TISA500)
Trabecular-iris space area at 500 μm (TISA500) will be measured in square millimeters (mm²) using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). TISA500 represents the cross-sectional area of the anterior chamber angle bounded by the trabecular meshwork, anterior iris surface, and reference lines at the scleral spur and 500 μm from the scleral spur. Changes from the preoperative baseline will be calculated at each postoperative follow-up visit.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Change in Trabecular-Iris Angle at 500 μm (TIA500)
Trabecular-iris angle at 500 μm (TIA500) will be measured in degrees using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). The angle will be determined from the anterior chamber angle geometry at 500 μm from the scleral spur. Changes from the preoperative baseline will be calculated at each postoperative follow-up visit.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Change in Iris Curvature (IC)
Iris curvature (IC) will be quantified in millimeters (mm) using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). Iris curvature is defined as the maximum perpendicular distance between the posterior iris surface and a reference line connecting the iris root to the pupillary margin. Changes from the preoperative baseline will be calculated at each postoperative follow-up visit.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Correlation Between Preoperative Ocular Biometric Parameters and Postoperative Visual Acuity
Preoperative ocular biometric parameters, including axial length (AL, mm), anterior chamber depth (ACD, mm), lens thickness (LT, mm), and white-to-white distance (WTW, mm), will be measured using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). Postoperative visual acuity will be assessed using a standardized visual acuity chart and expressed in logarithm of the minimum angle of resolution (logMAR) units. Correlations between each preoperative biometric parameter and postoperative visual acuity will be evaluated using Pearson's or Spearman's correlation coefficient, as appropriate. Correlation coefficients will be reported as dimensionless values ranging from -1 to +1
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
Correlation Between Preoperative Ocular Biometric Parameters and Postoperative Spherical Equivalent Refraction
Preoperative ocular biometric parameters, including axial length (AL, mm), anterior chamber depth (ACD, mm), lens thickness (LT, mm), and white-to-white distance (WTW, mm), will be measured using swept-source anterior segment optical coherence tomography (SS-OCT; CASIA2). Postoperative refractive status will be assessed by refraction examination and expressed as spherical equivalent refraction (SER) in diopters (D), calculated as spherical power plus half of the cylindrical power. Correlations between each preoperative biometric parameter and postoperative SER will be evaluated using Pearson's or Spearman's correlation coefficient, as appropriate. Correlation coefficients will be reported as dimensionless values ranging from -1 to +1.
Time frame: Preoperative baseline; postoperative day 1, week 1, month 1, and month 3
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Started May 2026 (actual). Primary completion is estimated for Mar 2028, 22 months after the start.
Of 182 non-industry observational studies under Cataract, half reached primary completion within 19 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 36. This study's planned 22 months is above that.
Counting every sponsor, half of 245 studies reached it within 17 months; a quarter within 9 and three quarters within 35.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Nanfang Hospital, Southern Medical University →