To analyze the incidence of uveal effusion observed in primary glaucoma and explore the relevant factors.

In this case control study, 692 primary glaucoma patients in the Second Hospital of Hebei Medical University from July 2016 to July 2017 were recruited, including 256 acute primary angle-closure glaucoma (APACG) patients, 368 chronic primary angle-closure glaucoma (CPACG) patients, and 68 primary open angle glaucoma (POAG) patients.Ultrasound biomicroscopy (UBM) was performed to determine the presence of uveal effusion, and to grade the effusion.The incidence of uveal effusion and the degree of effusion were analyzed statistically.The study protocol was approved by the Ethics Committee of the Second Hospital of Hebei Medical University.

The incidence levels of uveal effusion in the remission stage of APACG, the pre-clinical stage of APACG, and the progress stage of CPACG were 20.45% (54/264), 3.76% (8/213) and 1.45% (8/548), respectively; the incidence of uveal effusion among the three groups was statistically significant (χ²=105.02, P<0.05). The incidence levels of uveal effusion in the pre-clinical stage of APACG and the progress stage of CPACG were obviously lower than that in the remission stage of APACG (χ²=29.07, χ²=91.15; both at P<0.01). In the remission stage of APACG, the initial intraocular pressure was higher, and intraocular pressure fluctuation was larger in the patients with uveal effusion than that in the patients without uveal effusion, and these differences were statistically significant (Z=-3.626, Z=-4.022; both at P<0.05). Uveal effusion was detected in 54 eyes of the 50 APACG patients in the remission stage, including Grade 3 in 16 eyes, Grade 2 in 12 eyes, and Grade 1 in 26 eyes.Uveal effusion was demostrated in eight eyes of eight patients in the preclinical stage of APACG, and all at Grade 1.In the progress stage of CPACG, uveal effusion was also revealed in eight eyes of eight patients, all at Grade 1.In the remission stage of APACG, the degree of effusion was positively correlated with the initial intraocular pressure and the fluctuation of intraocular pressure (r_s=0.912, r_s=0.923; both at P<0.01). However, the degree of effusion was inversely associated with intraocular pressure after treatment (r_s=-0.269, P<0.05).

Uveal effusion can be observed in the remission and preclinical stages of APACG, and in the progress stage of CPACG.The remission stage of APACG shows both the highest rate and the severest degree of this complication.The degree of effusion is positively correlated with the initial intraocular pressure and the decrease in intraocular pressure, but it is inversely associated with intraocular pressure after treatment.

Glaucoma; Uveal effusion; Incidence; Relevant factors