Corneal Densitometry in Acute Primary Angle Closure Glaucoma

Purpose: Our purpose was to investigate the laser peripheral iridotomy (LPI) induced changes in corneal densitometry in acute primary angle closure glaucoma (PACG) cases during the post-laser 1 month period.

Material and methods: This prospective study included 21 eyes of 21 cases with first acute attack of PACG. All the eyes underwent LPI with neodymium: yttrium-aluminum-garnet (Nd: YAG) laser after the intraocular pressure (IOP) decreased to normal levels with maximal systemic and topical anti-glaucoma treatment and complete regression of clinically significant corneal edema. Central corneal thickness (CCT) and corneal density values were measured by densitometry software of Pentacam HR-Scheimpflug corneal topography over a 12-mm diameter of the cornea just before LPI and at the first week and the first month after LPI. Kolmogorov smirnov and paired-t tests were used for statistical analysis.

This prospective study included 21 eyes of 21 cases with first acute attack of PACG who had applied to emergency department of Ulucanlar Eye Research Hospital between March 2018 and January 2019. All the eyes underwent LPI with neodymium: yttrium-aluminum-garnet (Nd: YAG) laser after the IOP decreased to normal levels with maximal systemic and topical anti-glaucoma treatment and complete regression of clinically significant corneal edema.

During the acute attack ocular examination was performed at the emergency department including best-corrected visual acuity (BCVA) with Snellen charts, slit-lamb examination, fundus examination by +90 D lens, IOP measurements with Goldmann applanation tonometry, gonioscopy of the fellow eye with Goldmann three-mirror lens. Gonioscopy and fundus examinations were performed for the eyes with acute PACG after the regression of corneal edema.

All the cases had intravenous infusion of mannitol 20% (250-300 cc) at the emergency department. Oral acetazolamide 250 mg (3 times daily), oral potassium supplement, topical fixed-combination of beta-blocker and carbonic anhydrase inhibitors (twice daily) and brimonidine (twice daily). LPI procedures were performed within the first day of the attack (after 12-24 hours) by the same experienced physician (OA) with neodymium: yttrium-aluminum-garnet (Nd: YAG) laser under topical anesthesia with proparacain %0.5. Superior-nasal position (1 or 11 o'clock) was focused and 1 or more shots were performed (1-3 pulses per shot with 3-8 mJ energy).

Central corneal thickness (CCT) and CD values were measured by densitometry software of Pentacam HR-Scheimpflug corneal topography just before LPI and at the first week and the first month after LPI. All the measurements were performed by the same experienced clinician between 9 am and 2 pm under standard dim-light conditions without pupil dilatation.

Eligibility Criteria:
Inclusion Criteria:

* Acute primary angle closure glaucoma cases with first attack
* high IOP (\>40 mmHg)
* corneal edema
* red eye
* mid-dilated pupil
* presence of the symptoms like blurred vision, halos, ocular pain, headache, nausea and vomiting

Exclusion Criteria:

* The cases who had histories of any types of glaucoma or increased IOP before
* any corneal diseases like keratokonus
* corneal opacity
* dry eye or any ocular surface diseases
* ocular surgery or laser treatment
* trauma
* uveitis or other inflammation and contact lens use and diabetic cases were excluded