Biometry of the Anterior Segment of Eye and Analyses of the Factors That Influence the Width of Anterior Chamber Angle

1.Bingsong Wang¹
2. Ningli Wang²
3. Kun Lei²

¹Department of Ophthalmology, Beijing Shijitan Hospital, Beijing, P. R. China
²Tongren Eye Center, Beijing Tongren Hospital, Capital University of Medical Sciences, Beijing, P. R. China

PURPOSE: To identify and quantitatively analyze the anatomic factors those influence the width of anterior chamber angle.

METHOD: The subjects were selected from the ophthalmological outpatient department. Using anterior segment optical coherence tomography (Zeiss, USA, AC-OCT), anterior segment images of the eye were acquired and measured. The following parameters were included: Angle opening distance (AOD), Central anterior chamber depth(ACD), Corneal internal diameter(CD), Central cornea thickness(CT), 500um iris thickness(IT500), 1000um iris thickness(IT1000), Maximal iris thickness(ITM), Maximal thickness iris location(MIL), Iris curvature(IC), Pupil diameter(PD), Lens thickness(LT), Lens curvature(LC). Parameters which were significantly associated with angle opening distance were identified. Parameters which directly influenced angle opening distance were quantitatively analyzed through Multi-variable stepwise regression analysis and regression equations were established.

RESULTS: A total of 212 eyes of 212 subjects were analyzed. The following parameters were significantly associated with angle opening distance: ACD, CD, CT, IT500, IT1000, MIL, IC, PD, LT, and LC. Through multi-variable stepwise analysis, the following regression equations were established: AOD = -0.377 + 0.310* ACD -0.395* IT500 +0.236* LC -0.033 PD -0.222 IC.

CONCLUSION: The width of the anterior chamber angle was closely related with numerous anterior segment parameters. Among them, central anterior chamber depth, 500um iris thickness, lens curvature, pupil diameter and iris curvature directly influenced the width of anterior chamber angle.