Peripheral iris thickness and association with iridotrabecular contact after laser peripheral iridotomy in patients with primary angle-closure and primary angle-closure glaucoma

Figures & data

Figure 1 The determination of the iris thickness (IT500, IT750, and maximal iris thickness [MIT]) under the dark condition on anterior-segment optical coherence.

Figure 2 Anterior-segment optical coherence image in one meridian. Iridotrabecular contact was found in the dark-room condition (white stars).

Table 1 Detection of iridotrabecular contact in each quadrant by anterior-segment optical coherence tomography

	Superior	Inferior	Temporal	Nasal
Eyes, n (%)	44 (55.7%)	48 (60.8%)	18 (22.8%)	16 (20.2%)

Table 2 Detection of eyes with iridotrabecular contact by anterior-segment optical coherence tomography

Number of quadrants	0	1	2	3	4
Number of eyes (%)	28 (35.4%)	18 (22.8%)	20 (25.3%)	10 (12.7%)	3 (3.8%)

Table 3 Comparison of iridotrabecular contact (ITC)⁺ group and ITC⁻ group

Measures	ITC^+ group (n=33 eyes)	ITC^− group (n=46 eyes)	P-value
Age in years, mean (SD)	72.7 (8.5)	73.5 (6.9)	0.68
Men, number (%)	7 (21.2%)	12 (26.1%)	0.61
IOP, mmHg, mean (SD)	16.6 (3.7)	15.3 (3.3)	0.11
CT, μm, mean (SD)	541.9 (31.1)	523.5 (30.3)	0.18
ACD, mm, mean (SD)	2.41 (0.22)	2.37 (0.26)	0.51
LT, mm, mean (SD)	5.17 (0.27)	5.11 (0.31)	0.44
AL, mm, mean (SD)	22.29 (0.78)	22.49 (0.73)	0.23
LV, mm, mean (SD)	1.09 (0.24)	1.14 (0.28)	0.49
Pupil size, mm, mean (SD)	4.21 (0.92)	2.81 (0.90)	0.06
RE, diopter, mean (SD)	0.45 (1.25)	0.49 (2.12)	0.91

Abbreviations: SD, standard deviation; IOP, intraocular pressure; CT, corneal thickness; ACD, central anterior chamber depth; LT, lens thickness; AL, axial length; LV, lens vault; RE, refractive error.

Table 4 Comparison of iris parameters in iridotrabecular contact (ITC)⁺ group and ITC⁻ group

Measures	ITC^+ group (n=33)	ITC^− group (n=46)	Mean difference (95% CI)*	P-value
IT500, mm, mean (SD)	0.317 (0.097)	0.275 (0.071)	0.038 (0.002–0.075)	<0.05
IT750, mm, mean (SD)	0.372 (0.099)	0.321 (0.079)	0.043 (0.004–0.081)	<0.05
MIT, mm, mean (SD)	0.521 (0.096)	0.486 (0.083)	0.025 (−0.013 to 0.064)	0.19
I-Area, mm^2, mean (SD)	1.876 (0.291)	1.933 (0.292)	−0.021 (−0.141 to 0.099)	0.73

Note:

* Adjusted for age, sex, pupil size, and anterior chamber depth.

Abbreviations: CI, confidence interval; IT500, iris thickness measured at 500 μm from the scleral spur; SD, standard deviation; IT750, iris thickness measured at 750 μm from the scleral spur; MIT, maximal iris thickness; I-Area, iris area.

Table 5 Relationship of iris parameters and risk of iridotrabecular contact

	Multivariate-adjusted OR (95% CI)*	P-value
IT500	1.85 (1.03–3.32)	0.029
IT750	2.01 (1.11–3.63)	0.011
MIT	1.44 (0.83–2.50)	0.244
I-Area	0.97 (0.81–1.16)	0.406

Note:

* Adjusted for age, sex, pupil size, and anterior chamber depth.

Abbreviations: OR, odds ratio; CI, confidence interval; IT500, iris thickness measured at 500 μm from the scleral spur; IT750, iris thickness measured at 750 μm from the scleral spur; MIT, maximal iris thickness; I-Area, iris area.