Quantitative Analysis of Anterior Chamber following Peripheral Laser Iridotomy using Pentacam in Eyes with Primary Angle Closure

Abstract

Purpose.

To quantify the effects of laser peripheral iridotomy (LPI) on peripheral anterior chamber depth (PACD), central internal anterior chamber depth (CACD), and anterior chamber volume (ACV) using Rotating Scheimpflug Imaging System, i.e., Pentacam, on Asian Indian eyes.

Methods.

This was an institutional, prospective, nonrandomized, interventional study. Sixty-eight eyes of 68 consecutive patients with primary angle closure were enrolled. Pentacam scanned the anterior ocular segment with the 25-image acquisition scan protocol and PACD, CACD, and ACV values were obtained. The PACD was measured in nasal, temporal, superior, and inferior meridian at 4 mm and 8 mm circles. Nd:YAG laser iridotomy was performed. Preiridotomy, immediate postiridotomy, 1 week and 1 month postiridotomy data for PACD, CACD, and ACV were acquired. The t test and repeated-measures analysis of variance (ANOVA) and one-way ANOVA were used for statistical significance.

Results.

Pre-LPI ACV increased immediately after iridotomy (28.4 mm³; p≤0.001), at 1 week (15.9 mm³; p≤0.001), and at 1 month post-LPI (19.8 mm³; p=0.00). There was no change in CACD (p>0.05). Significant PACD deepening was observed at 4 mm and 8 mm in all meridians (p<0.001) at all visits.

Conclusions.

Laser peripheral iridotomy significantly increased the PACD and ACV. Extent of the LPI-induced PACD increase was enhanced with increasing distance from the optical axis.

Keywords

Anterior chamber volume Iridotomy Pentacam Primary angle closure

Get full access to this article

View all access options for this article.

References

Dandona

, Dandona

, Mandal

, Angle-closure glaucoma in an urban population in southern India: The Andhra Pradesh Eye Disease Study. Ophthalmology 2000; 107: 1710–6.

Quigley

H.A.

. Number of people with glaucoma worldwide. Br J Ophthalmol 1996; 80: 389–93.

Nolan

W.P.

, Foster

P.J.

, Devereux

J.G.

, Uranchimeg

, Johnson

G.J.

, Baasanhu

. YAG laser iridotomy treatment for primary angle closure in east Asian eyes. Br J Ophthalmol 2000; 84: 1255–9.

Fleck

B.W.

, Dhillon

, Khanna

, Fairley

, McGlynn

. A randomised, prospective comparison of Nd: YAG laser iridotomy and operative peripheral iridectomy in fellow eyes. Eye 1991; 5: 315–21.

Dada

, Mohan

, Sihota

, Gupta

, Pandey

R.M.

. Comparison of ultrasound biomicroscopic parameters after laser iridotomy in eyes with primary angle closure and primary angle closure glaucoma. Eye 2007; 21: 956–61.

Gazzard

, Friedman

D.S.

, Devereux

J.G.

, Chew

, Seah

S.K.

. A prospective ultrasound biomicroscopy evaluation of changes in anterior segment morphology after laser iridotomy in Asian eyes. Ophthalmology 2003; 110: 630–8.

Kashiwagi

, Abe

, Tsukahara

. Quantitative evaluation of changes in anterior segment biometry by peripheral laser iridotomy using newly developed scanning peripheral anterior chamber depth analyser. Br J Ophthalmol 2004; 88: 1036–41.

Rabsilber

T.M.

, Khoramnia

, Auffarth

G.U.

. Anterior chamber measurements using Pentacam rotating Scheimpflug camera. J Cataract Refract Surg 2006; 32: 456–9.

Foster

P.J.

, Buhrmann

, Quigley

H.A.

, Johnson

G.J.

. The definition and classification of glaucoma in prevalence surveys. Br J Ophthalmol 2002; 86: 238–42.

10.

Shaffer

R.N.

. Primary glaucomas. Gonioscopy, ophthalmoscopy and perimetry. Trans Am Acad Ophthalmol Otolaryngol 1960; 64: 112–27.

11.

Shaffer

R.N.

. A suggested anatomic classification to define the pupillary block glaucomas. Invest Ophthalmol 1973; 12: 540–2.

12.

Oka

, Otori

, Okada

, Miki

, Maeda

, Tano

. [Clinical study of anterior ocular segment topography in angle-closure glaucoma using the three-dimensional anterior segment analyzer Pentacam.] Nihon Ganka Gakkai Zasshi 2006; 110: 398–403.