Background: Determining the strategy of surgical treatment for chronic angle closure glaucoma (CACG) is still important. Purpose: To assess the efficacy, rates of successful intraocular pressure (IOP) lowering and the increase in anterior chamber angle for laser peripheral iridotomy (LPI) in patients with CACG. Material and Methods: We examined 31 patients (31 eyes; 18 women and 13 men) who had undergone LPI for CACG. Patient age ranged from 49 to 77 years (mean age, 64.8 ± 5.3 years). The indication for LPI was an anterior chamber angle of Shaffer grade 2 to 3 and the presence of optic neuropathy. Mean Maklakoff intraocular pressure (IOP) was 23.4 ± 1.2 mmHg. Results: Thirteen patients required surgery during the follow-up after LPI. Particularly, 10 eyes required phacoemulsification (PHACO) only, and 3 eyes, PHACO plus goniosynechialysis (GSL), because of decompensated IOP and an anterior chamber angle narrower than Shaffer grade 2 by gonioscopy. Kaplan-Meier survival analysis showed that the rates of successful IOP lowering for laser peripheral iridotomy (without the need for surgery, PHACO alone or PHACO plus GSL) at 12 months, 24 months and 36 months were 87.1%, 71.0% and 58.06%, respectively. Conclusion:The LPI is effective for opening the anterior chamber angle and reducing IOP over 6 months, but is less effective and does not allow opening the anterior chamber angle over a period exceeding 6 months. The LPI may be considered as a preparatory procedure in CACG, particularly in the presence of an acute angle-closure glaucoma attack in the fellow eye.

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The aim. To develop a predictive factor (PF) of anterior chamber (AC) angle closure based on biometric data and to compare its values with the Lowe coefficient and lens thickness to axial length factor (LAF) in healthy patients of different age, cataract patients and patients with chronic and acute angle-closure glaucoma. Materials and methods. The study was performed in 180 variously-aged (20 to 60 years) patients with different types of refraction, and in 20 patients with acute AC angle closure, in 20 patients with primary chronic angle-closure glaucoma and in 20 patients with cataract. The AC depth, the lens thickness (LT) and the axial length (AL) were measured by A-scan ultrasound biomicroscopy. Results. Based on ultrasound biometrics, a PF of anterior angle closure has been developed: PF = AC / AL / LT x 100. There was significant age-related decrease in the PF coefficient in patients with all types of refraction (p<0.001). In case of hypermetropia, PF was significantly less than in cases with myopia and emmetropia (p<0.001). Compared to the Lowe coefficient, the PF coefficient more sensitively showed the trend towards the closure of the AC angle in the age-refraction context. The AC depth in case of an acute glaucoma (2.3 ± 0.16 mm) was significantly less than that in case of chronic angle-closure glaucoma (2.4±0.21 mm) and differed significantly from that in case of cataract (3.32±0.33 mm), in all groups p < 0.001. At the same time, LT did not differ significantly in patients with acute glaucoma, chronic angle-closure glaucoma and cataracts (p>0.05). There was significant difference in PF coefficient between the groups of patients with an acute angle-closure glaucoma and cataracts, as well as chronic angle-closure glaucoma and cataracts (p<0.001). Its significance was higher than the significance of the Lowe coefficient between the respective groups. PF less than 2.5 was a significant risk factor for the closure of the AC angle.

Aim. To study the degree of angle opening and the decrease of intraocular pressure in primary angle-closure glaucoma (PACG) after cataract phacoemulsification and cataract phacoemulsification with goniosynechialysis (phaco + GLS). Materials and Methods. The study involved 28 patients (28 eyes) with primary chronic angle-closure glaucoma. The patients were divided into two groups, group 1 of 15 patients undergoing phaco with posterior chamber IOL implantation, and group 2 of 13 patients undergoing phaco with IOL implantation and GLS. The patients were followed for 24 months. Phaco was indicated in cases with IOP above 22 mmHg, appositional anterior chamber angle closure, and optic neuropathy; Phaco with GSL was indicated in cases of synechial angle closure and IOP above 22 mmHg Results. In group 1 after Phaco, postoperative anterior chamber angle opening was >20° in all quadrants. Postoperative IOP after 24 month follow-up it decreased by 32,6 % from the preoperative levels. In group 2 after Phaco+GSL, anterior chamber angle opened at least to 20° in three or more quadrants in all cases. Postoperative IOP after 24 month follow-up it decreased by 33.0% from the preoperative levels. Conclusions. Thus, phacoemulsification is an efficient procedure for PACG and appositional angle closure, leading to reopening of the anterior chamber angle with significant IOP reduction. Phacoemulsification alone does not lead to reopening of anterior chamber angle in cases with synechial angle closure, necessitating a combined surgery of phacoemulsification with GSL.

Anatomical factors predisposing to iridocorneal angle closure and ways to predict it are relevant to understanding the mechanism of primary angle-closure glaucoma (PACG). Acute angle closure, which is often the first presentation of PACG, frequently leads to irreversible optic disk damage with a decline in vision. If the iridocorneal angle is narrow, identification of angle closure threat is crucial for timely preventive intervention (laser iridotomy, laser peripheral iridoplasty, phacoemulsification of lens).Iridocorneal angle closure is known to be anatomically associated with shorter eyeball length, thicker lens and shallow anterior chamber [1][2][3][4]. Lowe [5,6] analyzed the role of changes in the lens in iridocorneal angle closure. He identified three key factors which lead to a decrease of anterior chamber depth. These are constitutional lens thickening, thickening of the lens with age, and lens edema secondary to cataract [7] According to Lowe, anterior displacement of the lens (relative lens position) plays a special role in iridocorneal angle closure [5] The latter factor was identified by Lowe as an important and reliable factor leading to iridocorneal angle closure. This factor is termed Lowe's coefficient or relative lens position (RLP). RLP = (AC + 1/2 LT) / AL × 10, where АС stands for anterior chamber depth (in mm), 1/2 LT is half thickness of the lens (in mm), and AL is the axial length of the eyeball (in mm).Like Lowe, Markowitz et al. (1985) [8] view changes in the lens, specifically the age-related ratio of lens thickness (LT) to eyeball axial length (AL), as key factors in angle closure. This relationship (lens thickness/axial length) is termed length axial factor (LAF). Studies by Markowitz demonstrated a significant difference in LT:AL ratio between patients with 'normal' eyes and angle-closure glaucoma patients of the same age.Marchini [9] used ultrasound biometrics to study the mechanism of different types of angle-closure glaucoma and obtained data comparable to those of Lowe and Markowitz. High reliability of Lowe's coefficient in prediction