CONTRIBUTION OF ULTRABIOMICROSCOPY IN PHACOMORPHIC GLAUCOMA: A PROSPECTIVE STUDY OF 25 EYES

Phacomorphic glaucoma secondary to crystalline intumescence leads to pupillary block and closure of the AIC.

It is a diagnostic and therapeutic emergency, as it can threaten the eye's anatomical and functional prognosis.

 High-resolution ultrasound biomicroscopy (UBM) is a minimally invasive technique for glaucoma, enabling us to pinpoint its mechanism and aid diagnosis by analyzing the various parameters of the iridocorneal angle.

The aim of our work is to determine the usefulness of UBM in assessing the iridocorneal angle,and the anterior segment before and after cataract surgery in phacomorphic glaucoma.

This is a prospective analytical study over a 14-month period (March 2021 to May 2022) that includes 25 eyes of 25 patients diagnosed with phacomorphic glaucoma.

Each patient underwent a complete bilateral ophthalmological examination, with measurement of visual acuity, slit lamp examination, measurement of intraocular pressure (IOP) by Goldmann's tonometry, gonioscopy, FO examination if possible.

Specular microscopy and UBM were performed before and at three months after cataract surgery.

UBM parameters analyzed included: corneal appearance, anterior chamber depth (ACD), iris configuration, lens position and configuration pre-operatively and of the anterior chamber angle and iris insertion level, AOD (Angel Opening Distance) 500, AOD 750 TIA (Trabecular-Iris Angle).

All patients underwent cataract extraction under locoregional anesthesia and after IOP reduction by peripheral iridoplasty, or systemic acetazolamide 500mg, or mannitol 20%.

 All patients were monitored at D1/D7/D30/M1/M3.

The mean age of our patients was 74.7 years, with a sex ratio of 1.

 Our study showed a mean reduction in mean IOP under maximum treatment from 45.36 ± 5.4 to 25.8 ± mmHg,

 The gonioscopic results were in agreement with the UBM results, which provided more specific measurements of AIC :

All angle parameters improved after cataract surgery.

 All patients had a mean angle of more than 20° in all four quadrants with a mean angle of (37.1+/-4.5), very similar to the angle status of the adelopic eye .

 The increase in AOD 250, AOD 500, AOD750, TIA, anterior chamber parameters were statistically significant, however there was no significant difference in iris parameters.

The mean anterior chamber angle on UBM increased by 1.43 mm, meaning a 75.6% increase on the mean preoperative value, with almost three times as many TIAs postoperatively.

 Gonioscopic examination three months after cataract surgery revealed open AIC in all patients with a mean Shaffer grading of (3.1 +/-1.0), and 30% of cases had peripheral anterior synechiae.

Biometric studies and UBM measurements of various AIC parameters in phacomorphic glaucoma, before and after cataract surgery, help to elucidate the pathophysiological of this type of glaucoma, and to determine its prognosis.