title: Quantification of trabecular-iris contact and its prevalence by optical coherence tomography in a healthy Caucasian population.
abstract: OBJECTIVE
  To determine the prevalence of trabecular-iris contact (TIC) and quantify this contact in healthy Caucasian individuals using Fourier-domain optical coherence tomography (FD-OCT).
  
  
  METHODS
  For this cross-sectional study, 2,012 eyes of 1,006 healthy subjects were recruited among individuals undergoing a routine ophthalmologic checkup. In each participant, age, sex, intraocular pressure, and spherical refractive error were first recorded along with anterior chamber depth and volume, central corneal thickness measured with the Pentacam, and axial length with the IOLMaster. Anterior chamber angle variables and the presence of TIC in the horizontal quadrants were determined by anterior segment FD-OCT (RTVue 100®). When TIC was observed, TIC length (TICL) and its percentage in relation to the length of the trabecular meshwork (TICL percentage) were also measured.
  
  
  RESULTS
  Trabecular-iris contact in the horizontal quadrants was observed in 34 eyes of 25 patients, representing 1.6% of the total number of eyes examined. In this subgroup of individuals, mean age was 55.8 years, 84% were women, and spherical refractive error ranged from -0.25 to 8.25 D. Eyes with TIC showed an angle width of less than 23.2 degrees and axial length shorter than 23.7 mm. Mean TICL was 239 ± 79 μm (103-495 μm) and mean TICL percentage was 46.9% ± 13.9% (17.2%-76.3%).
  
  
  CONCLUSIONS
  The prevalence of TIC was low in this population. Fourier-domain optical coherence tomography emerged as useful to assess its prevalence and quantify the extent of TIC.
authors.affiliation: Department of Ophthalmology, Hospital Universitario Clínico San Carlos, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid - Spain.|Centro Internacional de Oftalmología Avanzada, Madrid - Spain.
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: Fernández-Vigo
authors.affiliation: Centro Internacional de Oftalmología Avanzada, Madrid - Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: De-Pablo-Gómez-De-Liaño
authors.affiliation: Centro Internacional de Oftalmología Avanzada, Madrid - Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Fernández-Vigo
authors.affiliation: Centro Internacional de Oftalmología Avanzada, Madrid - Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Sánchez-Guillén
authors.affiliation: Department of Ophthalmology, Hospital Universitario Clínico San Carlos, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid - Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Santos-Bueso
authors.affiliation: Department of Ophthalmology, Hospital Universitario Clínico San Carlos, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid - Spain.
authors.forename: José María
authors.initials: JM
authors.lastname: Martínez-de-la-Casa
authors.affiliation: Department of Ophthalmology, Hospital Universitario Clínico San Carlos, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid - Spain.
authors.forename: Julián
authors.initials: J
authors.lastname: García-Feijóo
authors.affiliation: Centro Internacional de Oftalmología Avanzada, Madrid - Spain.|Department of Ophthalmology, Universidad de Extremadura, Badajoz - Spain.
authors.forename: José Ángel
authors.initials: JÁ
authors.lastname: Fernández-Vigo
mesh_terms: D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000033:anatomy & histology; D058452:Axial Length, Eye; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D007498:Iris / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D041623:Tomography, Optical Coherence / Q000379:methods; D014129:Trabecular Meshwork / Q000033:anatomy & histology*; D044465:White People / Q000706:statistics & numerical data*