Measurement of Retinal Changes in Primary Acute Angle Closure Glaucoma under Different Durations of Symptoms

Abstract

Purpose: To investigate the changes of retinal nerve fiber layer (RNFL) in patients after an attack of primary acute angle closure glaucoma (PAACG) and to assess the impact of attack time on prognosis of retinal changes.

Design: cross-sectional study.

Methods: Twenty-six patients with unilateral PAACG attack and cataracts from 2017 to 2019 were enrolled. Eyes with PAACG attack time less than 1 day constituted the group A (n = 13), while eyes with PAACG attack time more than 1 day constituted the group B (n = 13). All patients received phacoemulsification and viscogoniosynechialysis after intraocular pressure (IOP) lowering. All patients underwent ophthalmic examinations including IOP, best-corrected visual acuity (BCVA), and visual field (VF). Optical coherence tomography angiography (OCTA) was used to obtain circumpapillary RNFL vessel density (cpVD). Spectral domain optical coherence tomography (SD-OCT) was used to examine the peripapillary RNFL and macular ganglion cell complex (GCC). All patients accepted 2 assessments before and 1 month after the procedure.

Results: The IOP of all patients recovered to normal (12.77 ± 2.65 mm Hgvs. 12.77 ± 3.85 mmHg, p=0.834) after the procedure. Patients in the group A had better BCVA improvement than those in the group B (1.32 ± 0.84 vs. 0.50 ± 0.21, p=0.004), as well as better mean defect (MD) values from VF (-3.65 ± 2.54 vs -16.05 ± 5.99, p < 0.001). Compared with group B, patients in the group A had thicker macula (Fovea area: 255.00 ± 27.94 μm vs. 203.92 ± 59.73 μm, p=0.010), thicker GCC (82.62 ± 8.76 μm vs. 65.23 ± 18.56 μm, p=0.005), and thicker RNFL (105.08 ± 9.38 μm vs. 77.69 ± 20.23 μm, p < 0.001). Higher blood flow density in all-plexus peripapillary retina was observed in the group A eyes compared with group B (full sector: 0.56 ± 0.02 vs. 0.41 ± 0.07, p < 0.001). In both groups, the association between average RNFL thickness and cpVD as well as MD values and pattern standard deviation (PSD) values from VF was stronger (R ² = 0.58, 0.60, -0.54, respectively, all p < 0.001) than the association between GCC thickness and cpVD, as well as MD values and PSD values (R ² = 0.37, p=0.001; R ² = 0.37, p=0.001; R ² = -0.27, p=0.007).

Conclusion: Patients with attack time less than 1 day had better retinal thickness and all-plexus peripapillary retina blood flow density. Controlling the attack time could decrease retinal damage by PAACG.

Figure 1

Baseline and final logMAR BCVA of patients in this study. Dots below the line indicate improved visual acuity, and dots above the line indicate worse visual acuity.

Figure 2

Representative retinal damage images of 2 patients from different groups. (a) cpVD: OCT angiography image of a 6 × 6 mm section, centered on the optic disc head. Group A showed a better blood flow density than group B (yellow arrowheads). (b) ONH: RNFL thickness analysis examined by OCT. Group B was detected a more apparent RNFL defect in the superior region than group A (blue arrowheads). (c) GCC: ganglion cell complex thickness. An apparent GCC defect was detected in the inferotemporal area (red arrowheads). (d) MD: VF pattern deviation plot. Superior visual field loss was detected in group B patient.