Br J OphthalmolJuly 20206 citations

Association of anterior segment parameters and 5-year incident narrow angles: findings from an older Chinese population.

Jiang Yu, Wang Wei, Wang Lanhua, He Mingguang

View on PubMed DOI: 10.1136/bjophthalmol-2020-315852

AI Summary

This study found smaller baseline anterior ocular dimensions, thicker irises, and less light-to-dark change predict 5-year incident narrow angles in older Chinese adults, aiding early diagnosis.

Abstract

Purpose

To assess the association of anterior segment optical coherence tomography (AS-OCT) parameters and 5-year incident narrow angle in China.

Methods

This was a prospective cohort study of people aged 50 and older residing in Liwan District, Guangzhou, China. Random clustering sampling was used to identify adults aged 50 years and older in Liwan District, Guangzhou. In 2008 and 2013, this study was repeated and added AS-OCT imaging under dark and light conditions. Customised software (ZAAP) was used to analyse horizontal AS-OCT scans. Angle opening distance (AOD), trabecular iris space area (TISA), anterior chamber volume (ACV) and maximal iris thickness (ITM) were measured. Multiple logistic regression analysis models were used to investigate the associations of the final angle status with baseline AS-OCT parameters. ORs and 95% CIs were calculated.

Results

Of the 220 subjects with eligible AS-OCT images and gonioscopic results in 2008, the response rate was 77.3%. A total of 27 (15.9%) subjects developed narrow angles and 143 (84.1%) had open angles on gonioscopy in 2013. Subjects developed narrow angles had greater spherical equivalent and shallower anterior chamber depth, smaller angle parameters, thicker IT750 and ITM, smaller anterior chamber parameters, greater lens vault, and smaller dynamic parameters (ΔITM, ΔACA, ΔACV) at baseline. After adjusting confounders, the predictors of incident narrow angles included smaller AOD750, TISA750, ΔACA and greater ITM, ΔIarea.

Conclusions

Incident narrow angles were associated with smaller anterior ocular dimensions, thicker iris and smaller light-to-dark changes at baseline. These findings can help in early diagnosis in this population.

MeSH Terms

AgedAged, 80 and overAnterior Eye SegmentAsian PeopleBiometryChinaFemaleFollow-Up StudiesGlaucoma, Angle-ClosureGlaucoma, Open-AngleGonioscopyHumansIncidenceIntraocular PressureMaleMiddle AgedProspective StudiesTomography, Optical CoherenceTonometry, Ocular

Shields Classification

Ch. 3Gonioscopy and Other Techniques for Assessing the Anterior Segment

Ch. 9Clinical Epidemiology of Glaucoma

Ch. 12Pupillary Block Glaucomas

Key Concepts4

Incident narrow angles were associated with smaller anterior ocular dimensions, thicker iris, and smaller light-to-dark changes at baseline in an older Chinese population (n=220 subjects).

PrognosisCohortProspective Cohortn=220 subjectsCh10Ch13

Predictors of incident narrow angles in an older Chinese population (n=220 subjects) included smaller Angle Opening Distance at 750 microns from the scleral spur (AOD750), smaller Trabecular Iris Space Area at 750 microns from the scleral spur (TISA750), smaller dynamic Anterior Chamber Area (ΔACA), and greater Iris Thickness at its maximum (ITM) and dynamic Iris Area (ΔIarea), after adjusting for confounders.

PrognosisCohortProspective Cohortn=220 subjectsCh4Ch13

In a prospective cohort study of 220 subjects aged 50 and older residing in Liwan District, Guangzhou, China, 27 (15.9%) subjects developed narrow angles and 143 (84.1%) had open angles on gonioscopy over a 5-year period (2008 to 2013).

EpidemiologyCohortProspective Cohortn=220 subjectsCh10Ch13

Subjects who developed narrow angles had greater spherical equivalent, shallower anterior chamber depth, smaller angle parameters (AOD, TISA), thicker maximal iris thickness (ITM), smaller anterior chamber parameters (ACV), greater lens vault, and smaller dynamic parameters (ΔITM, ΔACA, ΔACV) at baseline, compared to those who maintained open angles, in an older Chinese population (n=220 subjects).