Changes in Anterior Segment Biometry by Laser Iridotomy in Eye With Shallow Anterior Chamber

Dong Ju Yeom; Joo Hwa Lee

doi:10.3341/jkos.2010.51.11.1479

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Yeom and Lee: Changes in Anterior Segment Biometry by Laser Iridotomy in Eye With Shallow Anterior Chamber

Original Article

J Korean Ophthalmol Soc 2010;51(11):1479-1484.

Published online: 7 September 2010

DOI: https://doi.org/10.3341/jkos.2010.51.11.1479

Changes in Anterior Segment Biometry by Laser Iridotomy in Eye With Shallow Anterior Chamber

Dong Ju Yeom, MD¹, Joo Hwa Lee, MD²

¹Department of Ophthalmology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea

²Department of Ophthalmology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea

Address reprint requests to Joo Hwa Lee, MD Department of Ophthalmology, Sanggye Paik Hospital #761-1 Sanggye 7-dong, Nowon-gu, Seoul 139-707, Korea Tel: 82-2-950-1096, Fax: 82-2-935-6904, E-mail: joohlee@paik.ac.kr

Received 9 March 2010 Accepted 18 August 2010

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 identify the impact of the presence of peripheral anterior synechia (PAS) on the depth of the anterior segment in patients with a shallow anterior chamber after laser iridotomy (LI) by analyzing changes in the anterior segment biometry using ultrasound biomicroscopy (UBM).

Methods

Twenty eyes of 20 patients with PAS and shallow anterior chamber, and another 20 eyes of 20 patients with shallow anterior chamber without PAS were studied. The changes in the anterior segment biometry for each group of patients were examined using gonioscopy and UBM before and after the LI.

Results

The central corneal thicknesses and scleral thicknesses of the two groups did not show significant differences (p > 0.05). The anterior chamber depths, anterior chamber angles, trabecular meshwork-iris distances, and angle-opening distances 500 increased significantly after the peripheral LI (p < 0.05) in both groups. However, the difference in the increases in the anterior segment biometries between the two groups was not statistically significant.

Conclusions

LI can increase the depth of the anterior chamber regardless of the presence of PAS.

Keywords: Anterior segment biometry, Laser iridotomy, Peripheral anterior synechia, Ultrasound biomicroscopy

References

1. Quigley HA, Miller NR, George T. Clinical evaluation of nerve fiber layer atrophy as an indicator of glaucomatous optic nerve damage. Arch Ophthalmol. 1980; 98:1564–71.

2. Levene RZ. Low tension glaucoma: a critical review and new material. Surv Ophthalmol. 1980; 24:621–64.

3. Salmon JF. Predisposing factors for chronic angle-closure glaucoma. Prog Retin Eye Res. 1999; 18:121–32.

4. Ritch R, Lowe RF. Angle-closure glaucoma: mechanisms and epidermiology. Ritch R, Shields MB, Krupin T, editors. The Glaucomas. 2nd ed.St. Louis: CV Mosby;1996. 2:chap.p. 37.

5. Lowe RF. Aetilogy of the anatomical basis for primary angle-clo-sure glaucoma. Biometrical comparasions between normal eyes and eyes with primary angle-closure glaucoma. Br J Ophthalmol. 1970; 54:161–9.

6. Foster PJ, Aung T, Nolan WP, et al. Defining “occludable” angles in population surveys: drainage angle width, peripheral anterior synechia, and glaucomatous optic neuropathy in east Asian people. Br J Ophthalmol. 2004; 88:486–90.

7. Inoue T. Distribution and morphology of peripheral anterior synechia in primary angle-closure glaucoma. Nippon Ganka Gakkai Zasshi. 1993; 97:78–82.

8. Rivera AH, Brown RH, Anderson DR. Laser iridotomy vs surgical iridectomy. Have the indications changed? Arch Ophthalmol. 1985; 103:1350–4.

9. Robin AL, Pollack IP. Argon laser peripheral iridotomies in the treatment of primary angle closure glaucoma: long-term follow-up. Arch Ophthalmol. 1982; 100:919–23.

10. Hong C, Hahn SH, Sohn YH. Argon laser iridotomy for angle-clo-sure glaucoma. J Korean Ophthalmol Soc. 1983; 24:807–11.

11. Han CW, Kim JW. Effect of YAG laser iridotomy on IOP in chronic angle-closure glaucoma. J Korean Ophthalmol Soc. 1995; 36:1730–6.

12. Lee HB, Hwang WS, You JM, et al. Sequential Argon and Nd:YAG laser iridotomies in angle closure glaucoma. J Korean ophthalmol Soc. 1999; 40:2245–51.

13. Gazzard G, Friedman DS, Devereux FG, et al. A prospective ultrasound biomicroscopy evaluation of changes in anterior segment morphology after laser iridotomy in Asian eyes. Ophthalmology. 2003; 110:630–8.

14. Jin JC, Anderson DR. The effect of iridotomy on iris contour. Am J Ophthalmol. 1990; 110:260–3.

15. Caronia RM, Liebmann JM, Stegman Z, et al. Increase in iris-lens contact after laser iridotomy for papillary block angle closure. Am J Ophthalmol. 1996; 122:53–7.

16. Kashiwagi K, Abe K, Tsukahara S. Quantitative evaluation of changes in anterior segment biometry by peripheral laser iridotomy using newly developed scanning peripheral anterior chamber depth analyzer. Br J Ophthalmol. 2004; 88:1036–41.

17. Pavlin CJ, Sherar MD, Foster FS. Subsurface ultrasound imaging of the intact eye. Ophthalmology. 1990; 97:244–50.

18. Pavlin CJ, Harasiewicz K, Sherar MD, Foster FS. Clinical use of ultrasound biomicroscopy. Ophthalmology. 1991; 98:287–95.

19. Marchini G, Pagliarusco A, Toscano A, et al. Ultrasound biomicroscopic and conventional ultrasonographic study of ocular dimensions in primary angle-closure glaucoma. Ophthalmology. 1998; 105:2091–8.

20. Ishikawa H, Liebmann J, Ritch R. Quantitiative assessment of the anterior segment using ultrasound biomicroscopy. Curr Opin Ophthalmol. 2000; 11:133–9.

21. Mandell MA, Palvin CJ, Weisbrod DJ, et al. Anterior chamber depth in plateau iris syndrome and papillary block as measured by ultrasound biomicroscopy. Am J Ophthalmol. 2003; 136:900–3.

22. Yoon KC, Won LD, Cho HJ, et al. Ultrasound biomicroscopic changes after laser iridotomy or trabeculectomy in angle-closure glaucoma. Korean J Ophthalmol. 2004; 18:9–14.

Figure 1.

UBM images of the temporal angle of eyes before and after LI in PAS-positive eye and PAS-negative eye that show flattening of the iris and widening of the angle in detail. (A) Before LI in PAS-negative eye. (B) After LI in PAS-negative eye. (C) Before LI in PAS-positive eye. (D) After LI in PAS-positive eye.

Table 1.

Patients' data base

	Study subjects (n=40)
	PAS-positive (n=20)	PAS-negative (n=20)
Gender		
Male	5	1
Female	15	19
Age (years)		
Mean ± SD^*	65.5 ± 11.0	66.2 ± 6.7
Range	49∼79	57∼82
Laterality of affected eye		
Right	10	10
Left	10	10
Refractive errors (^† S.E.: ^‡ D)		
Mean ± SD^*	0.900 ± 0.609	0.500 ± 0.846
Range	−0.25∼+2.00	−0.75∼+2.75
Intraocular pressure (mmHg)		
Mean ± SD^*	17.4 ± 2.5	16.6 ± 4.4
Range	13∼23	8∼24

^* SD: standard deviation

^† S.E.: spherical equivalent

^‡ D: Diopter.

Table 2.

UBM parameters in PAS-negative and PAS-positive eyes before and after LI

UBM parameters	PAS-positive s			PAS-negative
UBM parameters	Before LI	After LI	p value	Before LI	After LI	p value
CCT^* (μ m)	497.7 ± 14.6	498.5 ± 10.2	0.666	493.7 ± 13.5	494.7 ± 11.4	0.428
ACD^† (mm)	1.96 ± 0.11	1.97 ± 0.09	0.049	2.15 ± 0.11	2.17 ± 0.09	0.021
ACA^‡ (°)	11.71 ± 0.98	14.08 ± 0.99	0.006	14.57 ± 0.66	18.42 ± 0.68	<0.001
ST^§ (μ m)	866.1 ± 2.56	866.3 ± 2.38	0.444	861.5 ± 2.33	862.3 ± 3.00	0.238
TID^∏ (μ m)	90.43 ± 0.77	110.93 ± 1.14	<0.001	103.68 ± 0.65	125.87 ± 0.59	<0.001
AOD500^# (μ m)	120.37 ± 2.96	150.43 ± 2.12	<0.001	131.75 ± 2.37	162.43 ± 1.35	<0.001

^* CCT=Central corenal thickness

^† ACD=Anterior chamber depth

^‡ ACA=Anterior chamber angle

^§ ST=Scleral thickness

^∏ TID= Trabeculariris distance

^# AOD500=Angle opening distance 500.

Table 3.

UBM parameters depending on the numbers of quadrants eyes in PAS-positive eyes before and after LI

UBM parameters	1 quadrant			2 quadrants			3 quadrants			4 quadrants
UBM parameters	Before LI	After LI	p value	Before LI	After LI	p value	Before LI	After LI	p value	Before LI	After LI	p value
CCT^* (μ m)	503.75	502.50	0.668	485.00	48.00	<0.001	507.50	502.50	0.092	487.14	494.28	0.008
	± 10.60	± 5.97		± 0.00	± 0.00		± 6.45	± 8.66		± 16.03	± 12.05	
ACD^† (mm)	2.05	2.04	0.598	2.15	2.10	<0.001	1.86	1.91	0.375	1.88	1.92	0.008
	± 0.92	± 0.72		± 0.00	± 0.00		± 0.75	± 0.75		± 0.55	± 0.63	
ACA^‡ (°)	12.09	14.53	<0.001	10.50	13.00	0.030	12.00	15.00	<0.001	11.28	13.25	<0.001
	± 1.22	± 1.48		± 0.57	± 0.81		± 1.36	± 1.71		± 1.18	± 1.43	
ST^§ (μ m)	860.9	862.8	0.050	862.5	863.7	0.391	882.5	882.1	0.791	863.3	861.7	0.142
	± 19.44	± 17.86		± 6.45	± 6.29		± 4.83	± 7.29		± 15.98	± 16.67	
TID^∏ (μ m)	94.68	113.12	<0.001	95.00	110.00	0.024	89.68	112.81	<0.001	85.35	107.67	<0.001
	± 6.60	± 9.22		± 4.08	± 5.77		± 4.98	± 5.46		± 2.69	± 6.15	
AOD500^# (μ m)	121.71	151.40	<0.001	118.75	150.00	0.002	124.68	156.87	<0.001	116.60	148.57	<0.001
	± 8.38	± 7.74		± 4.78	± 4.08		± 10.71	± 4.03		± 4.31	± 12.16	

^* CCT=Central corenal thickness; Trabeculariris distance

^† ACD=Anterior chamber depth

^‡ ACA=Anterior chamber angle

^§ ST=Scleral thickness

^∏ TID=

^# AOD500=Angle opening distance 500.

Table 4.

UBM parameters in PAS-positive and PAS-negative eyes in the Superior, Inferior, Temporal, and Nasal quadrants before and after LI

UBM parameters	Superior						Inferior
	PAS-positive			PAS-negative			PAS-positive			PAS-negative
	Before LI	After LI	p value	Before LI	After LI	p value	Before LI	After LI	p value	Before LI	After LI	p value
ACA^* (°)	10.90	14.25	<0.001	14.45	18.00	0.034	11.85	15.25	0.004	15.25	19.10	<0.001
	± 0.64	± 1.25		± 0.68	± 1.45		± 1.22	± 1.11		± 1.11	± 1.07	
TID^† (μ m)	89.75	109.50	<0.001	102.75	125.50	0.001	90.50	104.00	<0.001	104.00	125.50	<0.001
	± 5.72	± 8.25		± 4.72	± 7.93		± 6.46	± 5.52		± 5.52	± 9.44	
AOD500^‡ (μ m)	116.50	149.25	<0.001	132.00	160.00	0.025	119.75	131.00	<0.001	131.00	161.00	0.040
	± 8.59	± 7.82		± 9.65	± 8.73		± 6.58	± 7.18		± 7.18	± 8.04	

	Temporal						Nasal
	PAS-positive			PAS-negative			PAS-positive			PAS-negative
	Before LI	After LI	p value	Before LI	After LI	p value	Before LI	After LI	p value	Before LI	After LI	p value
ACA^* (°)	13.05	15.40	<0.001	14.90	18.90	<0.001	11.05	13.10	0.041	13.70	17.70	0.020
	± 1.19	± 1.53		± 0.64	± 0.91		± 0.68	± 1.48		± 0.73	± 1.45	
TID^† (μ m)	90.00	112.25	<0.001	103.75	125.75	0.030	91.50	111.25	0.040	104.25	126.75	<0.001
	± 7.25	± 6.97		± 6.04	± 9.90		± 6.09	± 7.92		± 5.68	± 10.10	
AOD500^‡ (μ m)	123.25	153.00	<0.001	131.75	161.50	0.009	122.00	153.50	0.029	136.25	163.25	0.037
	± 6.93	± 9.23		± 7.48	± 8.12		± 9.09	± 10.52		± 9.30	± 7.48	

^* ACA=Anterior chamber angle

^† TID=Trabeculariris distance

^‡ AOD500=Angle opening distance 500.

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