Pre-clinical diagnosis of early postoperative course features after surgeries of non-fistulizing types in case of primary open-angle glaucoma

Purpose

To reveal a symtomatology of hypotonic syndrome in conditions of absence of clinically diagnosed complications after operations of non-penetrating type (NPDS and MNDPS).


Material and methods

There were selected 58 patients (84 eyes) who underwent MNDPS, in the first group. The 2nd group included 56 patients (71 eyes) with POAG, who underwent NDPS. Conventional clinical functional examinations were added with B-scanning and optical coherent tomography (OCT) of the anterior segment of the eye. Tonometry, ultrasound B-scanning of choroid, examinations of anterior chamber (AC) depth and suprachoroidal space (SCS) were carried out preoperatively and in various postoperative follow-ups: 4 hours, 1, 3, 7, 14 days, 1 month later.


Results

There were 2 types of postoperative eye reaction according to a summary evaluation of investigated parameters. Patients with a minimum reaction and a fast recovery of investigated parameters were attributed to the type I of postoperative reaction and averaged 80% of all performed surgeries included 72 eyes (46.4%) after MNPDS and 53 eyes (34.2%) after NPDS. In mentioned cases a sharp hypotony was not observed in postoperative follow-up. Minimal IOP data averaged 6.6±0.07 and 6.6±0.09 mmHg and were noted 4 hours after surgery. In subsequent follow-up the IOP increased smoothly and reached 17.4±0.08 and 16.6±0.08 mmHg 14 days after surgical intervention. Maximal choroidal reaction was revealed in the same period like the IOP decrease 1 day after operation. Coroidal changes were short-term and its parameters returned to initial data 7 days later.

Insignificant enlargement of SCSpace was registered during first 3 days after surgical intervention in the range 0.05-0.09 mm. The 2nd type of reaction was characterized by more intensive deviations of investigated parameters. The IOP in this group remains in the level of 6-7 mm Hg up to 3 days postoperatively and took place as a rule in case of the glaucoma stage III: 3 cases (4.1%) after NPDS and 2 cases (2.3%) after MNPDS. A maximum increase of choroidal thickness detected one day later was 1.12±0.04 mm and 1.24±0.02 mm and maintained up to 14 days after operation slowly returning to the initial values. Associated with pronounced changes of choroid in patients with the 2nd type of reaction the ciliochoroidal detachment up to 1.0 mm was diagnosed by ultrasound scanning that was accompanied with a decrease of anterior chamber depth by 0.2-0.5 mm within the OCT-Visante examination. Choroidal detachment (CD) was observed in 2 patients (1.3%) after MNDPS and in 4 patients (2.5%) after NPDS and did not associate with symptomatology typical for a classical CD and spontaneously disappeared without additional therapeutic or surgical interventions.

Conclusions

Application of highly informative up-to-dated B-scanning equipment such as “OTI-Scan 2000”, Visante OCT allows to reveal symptomatology of hypotonic syndrome after operation of non-penetrating type (NPDS and MNPDS) in absence of clinically diagnosed complications and to evaluate objectively the degree of surgical intervention traumatism.

Keywords

non-penetrating operation, micro non-penetrating operation, suprachoroidal space, choroidal thickness, hypotonia.