AIM:To observe the changes of anterior segment before and after phacoemulsification and intraocular lens implantation in patients with primary angle-closure glaucoma(PACG)by Pentacam system,so as to assess the efficacy and the influence factors for treating PACG.

METHODS:One hundred and sixty-three patients(178 eyes)with PACG were included in the presented study, which were classified to acute PACG(APACG, 87 patients with 92 yes)and chronic PACG(CPACG, 76 patients with 86 eyes).Phacoemulsification and posterior-chamber IOL(PC-IOL)implantations were performed for all eyes and combined with goniosynechialysis if necessary. Visual acuity, intraocular pressure(IOP), the central anterior chamber depth(ACD),anterior chamber volume(ACV)and peripheral anterior chamber angle(ACA)were examined by Pentacam system pre-operatively and 1d, 1wk, 3 and 6mo post-operatively.

RESULTS:In both groups, the IOP was significantly decreased after operations(P< 0.01), Which in patients with APACG were 51.17±6.58mmHg and 14.32±2.66mmHg and in patients with CPACG were 33.25±5.45mmHg and 15.86±3.54mmHg. The IOP significantly decreased more in patients with APACG than that in patients with CPACG(P<0.05). The visual acuity was also improved after operations(P<0.01)and it improved more in patients with APACG than that in patients with CPACG(P<0.01). Postoperative gonioscopy(at 3mo)results demonstrated that the angle of anterior chamber opened wider and the range of peripheral anterior synechiae(PAS)reduced after surgeries. The ACD, ACV and ACA were increased significantly after surgeries(P<0.01)detected by Pentacam in all patients. In patients with APACG: ACD before and after surgeries were 1.69±0.14mm vs 2.83±0.10mm respectively; ACV were 68.34±14.02μm³ vs 145.85±14.36μm³; ACA were 18.28°±4.46° vs 30.50°±4.23°. In patients with CPACG: ACD before and after surgeries were 1.96±0.20mm vs 2.82±0.10mm; ACV were 88.19±15.86μm³ vs 141.28±14.64μm³; ACA were 22.03°±4.48°vs 31.65°±4.62°. Compared to CPACG group, the ACD, ACV and ACA of patients with APACG were significantly lower before operations(P<0.01)while after operations, except for ACV, no differences were found on the three indicators(P>0.05). The changes on ACD, ACV and ACA before and after operations were significant between patients with APACG and CPACG(P<0.01).

CONCLUSION:Pentacam system can directly demonstrate the changes of anterior segment before and after phacoemulsification combined with IOL for angle-closure glaucoma. It demonstrates that the anterior segments maybe closely related to the mechanisms of PACG, the changes of which contributes significantly to the clinical effects of phacoemulsification and PC-IOL implantation for both APACG and CPACG patients. The difference of clinical efficacy for APACG and CPACG is maybe correlatied to the different mechanisms.