Journal List > J Korean Ophthalmol Soc > v.57(9) > 1010393

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Park, Kim, Lee, and Lee: Iris-trabecular Contact Index Change after Cataract Surgery in Acute Angle Closure Glaucoma
Original Article

J Korean Ophthalmol Soc 2016;57(9):1400-1406.

Published online: 25 September 2016

DOI: https://doi.org/10.3341/jkos.2016.57.9.1400

Iris-trabecular Contact Index Change after Cataract Surgery in Acute Angle Closure Glaucoma

Jae Hong Park, MD, Ho Soong Kim, MD, Tae Heon Lee, MD, Kyung Heon Lee, MD

Busan Sungmo Eye Hospital, Busan, Korea

Address reprint requests to Kyung Heon Lee, MD Busan Sungmo Eye Hospital, #409 Haeun-daero, Haeundae-gu, Busan 48064, Korea Tel: 82-51-743-0775, Fax: 82-51-743-0776 E-mail: sungmobusan@hanmail.net

Received 3 March 2016       Revised 22 June 2016       Accepted 8 August 2016

Copyright © 2016 Korean Ophthalmological Society

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

To evaluate the change of iris-trabecular contact index (ITC index) after cataract surgery in acute angle closure glaucoma.

Methods

Twelve patients (17 eyes) who had a history of acute angle closure glaucoma underwent swept source optical coherence tomography before and after cataract surgery. Correlations between lens vault (LV), ITC index and intraocular pressure (IOP), anterior chamber depth (ACD), anterior chamber volume (ACV), and angle parameters were analyzed before and after cataract surgery.

Results

IOP (p = 0.007), ACD (p < 0.001), ACV (p < 0.001), angle parameters (p = 0.001), and ITC index (p = 0.012) were improved after cataract surgery. ITC index decreased from 88.42 ± 23.59% to 48.91 ± 35.13% after cataract surgery (p = 0.012). There was no correlation between LV and ACD (p = 0.075), ACV (p = 0.864), angle parameter (p = 0.112–0.707), or ITC index (p = 0.288) before cataract surgery. The correlations between ITC index and IOP (p = 0.021), ACD (p = 0.002), ACV (p < 0.001), and angle parameter (p = 0.001–0.030) were statistically significant before surgery but not statistically significant (p = 0.223/0.206/0.761/0.096–0.819) after surgery.

Conclusions

ITC index significantly improved after cataract surgery, but part of angle closure was not resolved in some cases of acute angle closure glaucoma.

Keywords: Acute angle closure glaucoma, Cataract surgery, Iris-trabecular contact index, Lens vault

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Figure 1.
Swept source optical coherence tomography image illustrating anterior chamber depth (ACD) and lens vault (LV). White arrows indicate the scleral spur.
jkos-57-1400f1.tif
Figure 2.
Cross-section image of angle structure illustrating angle parameters. (A) Angle opening distance at 500 μ m from scleral spur (AOD500) and trabecular-iris angle 500 (TIA500). (B) Trabecular-iris surface area 500 (TISA500) is expressed by dot printed and angle recess area 500 (ARA500) is expressed by a hatched box.
jkos-57-1400f2.tif
Figure 3.
Swept source optical coherence tomography image illustrating a single frame of anterior chamber. (A) The red colored “x” are the scleral spurs (SS) and the “+” are the iris-trabecular contact end points (EP). (B) Iris-trabecular con-tract (ITC) chart with blue area representing the amount and the distribution of iris-trabecular contact. Red line is the consecutive line of the scleral spur and the green line is the consecutive line of end point. (C) Iris-trabecular contact graph with X axis representing the degree of the angle, Y axis repre-senting iris-trabecular contact. “+” means the contact with iris and trabecular meshwork and “-” means non-contact between the two structures.
jkos-57-1400f3.tif
Table 1.
Patient baseline characteristics
  Mean ± SD Range
Age (years) 64.4 ± 5.7 54–76
Gender (male:female) 5:7  
Right eye:Left eye 7:10  
Lens vault (μ m) 738.6 ± 303.2 372–1,405
Axial length (mm) 22.29 ± 1.37 19.69–24.36
Endothelial cell count (/mm2) 2,400.5 ± 744.4 409–3,194

Values are presented as mean ± SD unless otherwise indicated.

SD = standard deviation.

Table 2.
Preoperative and postoperative outcomes
  Preoperation Postoperation p-value
BCVA (log MAR) 0.38 ± 0.44 0.11 ± 0.17 <0.001
Intraocular pressure (mm Hg) 20.29 ± 7.56 15.71 ± 4.04 0.007
Glaucoma medication (No.) 1.2 ± 1.2 0.2 ± 0.8 0.001
Anterior chamber depth (mm) 1.85 ± 0.33 3.50 ± 0.39 <0.001
Anterior chamber volume (mm3) 79.06 ± 22.65 146.71 ± 22.60 <0.001
Anterior chamber width (mm) 10.37 ± 0.73 10.88 ± 0.56 0.235
Iris volume (mm3) 24.98 ± 5.65 26.31 ± 5.49 0.451
Angle parameter
 AOD (mm) 0.30 ± 0.10 0.51 ± 0.12 0.001
 ARA (mm2) 0.15 ± 0.04 0.21 ± 0.05 0.001
 TISA (mm2) 0.12 ± 0.03 0.18 ± 0.04 0.001
 TIA (°) 20.72 ± 7.91 34.08 ± 6.03 0.001
ITC index (%) 88.42 ± 23.59 48.91 ± 35.13 0.012
Invisible range (°) 26.77 ± 38.59 23.62 ± 36.86 0.561

Values are presented as mean ± SD unless otherwise indicated.

BCVA = best corrected visual acuity; AOD = angle opening distance; ARA = angle recess area; TISA = trabecular-iris surface area; TIA = trabecular-iris angle; ITC=iris-trabecular contact.

Table 3.
Correlation between lens vault and the other parame-ters before cataract surgery
  Spearman's rho p-value
IOP (mm Hg) 0.600 0.023
Anterior chamber depth (mm)3 −0.490 0.075
Anterior chamber volume (mm3) −0.051 0.864
Angle parameter
 AOD (mm) ARA (mm2) −0.115 −0.181 0.707 0.553
 TISA (mm2) −0.462 0.112
 TIA (°) −0.132 0.668
ITC index (%) 0.398 0.288

IOP = intraocular pressure; AOD = angle opening distance; ARA = angle recess area; TISA = trabecular-iris surface area; TIA = trabecular-iris angle; ITC = iris-trabecular contact.

Table 4.
Correlation between pre (1)/postoperative (2) iris-tra-becular contact index and the other parameters
  Spearman's rho p-value
Preoperation (1)
 Intraocular pressure (mm Hg) 0.479 0.021
 Anterior chamber depth (mm) −0.617 0.002
 Anterior chamber volume (mm3) −0.752 <0.001
 Angle parameter
  AOD (mm) −0.452 0.030
  ARA (mm2) −0.613 0.002
  TISA (mm2) −0.642 0.001
  TIA (°) −0.580 0.004
 Iris volume (mm3) 0.513 0.012
Postoperation (2)
 Intraocular pressure (mm Hg) 0.312 0.223
 Anterior chamber depth (mm) 0.323 0.206
 Anterior chamber volume (mm3) −0.080 0.761
 Angle parameter
  AOD (mm) −0.060 0.819
  ARA (mm2) −0.417 0.096
  TISA (mm2) −0.348 0.170
  TIA (°) −0.135 0.606
 Iris volume (mm3) 0.053 0.841

AOD = angle opening distance; ARA = angle recess area; TISA = trabecular-iris surface area; TIA = trabecular-iris angle.

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