Yag Laser Versus Sequential Yag-Argon for Peripheral Iridotomy in Acute Angle Closer Glaucoma

Case Series

J Ophthalmol & Vis Sci. 2023; 8(3): 1084.

Yag Laser Versus Sequential Yag-Argon for Peripheral Iridotomy in Acute Angle Closer Glaucoma

Haddani O1,3*; Khamaily M1,3; Maarouf I1,3; Mouhib L1,3; Razzak A1,2; Bouazza M1,2; Elbelhadji M1,2,3

¹Department of Ophthalmology at International University Hospital Mohamed VI of Casablanca, Morocco

²Department of Ophthalmology at International University Hospital Cheikh Khalifa of Casablanca, Morocco

³University Mohamed VI of Health Sciences, Morocco

*Corresponding author: Haddani O Department of Ophthalmology at International University Mohamed VI, University Mohamed VI of Health Sciences, Clecy street, Oasis, Casablanca, 20104, Morocco. Tel: +212623069606 Email: othman-haddani96@hotmail.fr

Received: April 24, 2023 Accepted: May 25, 2023 Published: May 31, 2023

Abstract

Acute angle closer glaucoma accounts for 10% to 20% of all glaucoma cases. Laser peripheral iridotomy is considered the standard treatment modality for predisposed subjects it can be performed with Argon, YAG or both. The combined method provides the benefits of each laser while minimizing their respective drawbacks.

This is a prospective study over a period of 18 months on 50 eyes: 25 patients with acute angle closer glaucoma: for each patient, a peripheral iridotomy with YAG laser alone on one eye and sequential iridotomy with Argon laser then YAG in the other eye.

The results showed that the YAG only technique is less painful (2.5/10 versus 7.5/10), needs less time (5 minutes) and uses less energy than the combined method. Meanwhile the Argon-YAG technique showed less complication for dark irises.

Ho and Fan [1] did a combined technique for iridotomy in 20 eyes with dark irises. They performed it with only a mean of 4 YAG impacts versus 12 in our study for the combined technique group. In term of complications, they had a 10% hyphema and endothelial opacity; we had none of both complications in our combined technique cases.

The sequential method remains the most widely used, it theoretically offers an advantage over the YAG laser only in the treatment of darker irises with less complications. Meanwhile the YAG only technique is better for the comfort of the patient, it is quicker, brings less pain and delivers less energy to the iris.

Keywords: Peripheral iridotomy; Acute angle closer glaucoma; nd: YAG neodymium; Argon laser; Sequential method; ark irises.

Introduction

Acute angle Closer Glaucoma (ACG) accounts for 10% to 20% of all glaucoma cases.

Unsurprisingly, acute ACG is estimated to cause blindness in two to five times as many people as primary open-angle glaucoma.

Studies have shown that 22% of subjects with suspected angle closure may progress to ACG and 28.5% of susceptible subjects may develop it within 5 years if no treatment is prescribed.

Laser Peripheral Iridotomy (PI) is considered the standard treatment modality for predisposed subjects.

Angle-closure glaucoma is commonly treated by PI.

It consists of perforating the stroma of the iris by focusing on it one or more laser impacts and to create an orifice of sufficient size to allow an unobstructed flow of the aqueous humor from the posterior chamber to the anterior chamber, thus preventing or lifting permanent or definitive apposition of the iris against the trabecular meshwork and thus suppressing the gradient between the chambers to flatten the iris.

This procedure can be carried out using either argon or Nd: YAG (neodymium: yttrium–aluminum–gar- net) lasers [2].

The YAG laser is effective for Caucasian population because of light colored irises.

For dark irises (Asian, African) the YAG laser is less effective because of a highly pigmented, thick stroma and fewer crypts irises [3].

The use of Argon laser (photocoagulation) iridotomy is not as effective in these types of irises, according to studies [1,3,4]. To overcome this limitation, a proposed solution is to use a sequential approach with both argon and Nd:YAG lasers [1,2,5,6]. This method provides the benefits of each laser while minimizing their respective drawbacks. Pretreatment with argon laser causes iris contraction and coagulation of nearby vessels, reducing tissue thickness and minimizing iris hemorrhage [7]. The Nd: YAG laser is then used for the final iris perforation, resulting in minimal pigment dispersion and a low closure rate.

Moroccan population has mostly dark pigmented irises.

Patients and Methods

We used ARGON Laser and YAG Laser.

The objective of the study was to evaluate, in a comparative way, the efficiency and safety of PI by YAG laser alone versus ARGON laser then YAG.

This is a prospective study over a period of 18 months from January 2021 to august 2022 done in the department of ophthalmology at the international university Hospital Mohamed VI on 50 eyes: 25 patients with indications for PI: for each patient, a PI with YAG laser alone on one eye and combined PI with ARGON laser then YAG in the other eye.

We included in our study patients with a narrow angle either an attack of acute glaucoma by angle closure or chronic glaucoma by angle closure.

The data collected were the number of impacts, the energy delivered, the presence or absence of bleeding and hypertonia. We also evaluated per and post-laser pain using the visual analog scale and the time for both procedures.

Results

The average age was 48,2 years old.

The sex ratio was 0,78 with a female predominance.

The average follow-up was 14 months with a 100% functional PI for the 2 methods.

Iridotomy closure was not observed during follow up.

The pain felt during the PI was evaluated by the visual analog pain scale from 1 to 10. It was an average of 2.5/10 [2.02-3.38] for the YAG method alone while in the combined method it was 7.5/10 [6.39-8.17] (Figure 1).