ANATOMO-TOPOGRAPHIC AND HYDRODYNAMIC PARAMETERS OF THE EYE AFTER CATARACT PHACOEMULSIFICATION

Background: Removal of the native lens alters spatial relationships between anterior eyeball structures and results in fluctuations in intraocular pressure. Intraocular pressure control is important for the prevention of early postoperative complications. 

Aim: To study anatomic, topographic and hydrodynamic changes of the eyeball after uncomplicated cataract phacoemulsification with intraocular lens implantation. 

Materials and methods: 75  eyes of 75  patients after uncomplicated cataract phacoemulsification were studied. All patients underwent ultrasound biomicroscopy, electronic tonography and biomechanics study on ocular response analyzer (before the surgery, in 2  weeks, 1 and 3  months after the surgery). 

Results: We found significant increase in anterior chamber depth, distance trabecula-iris at 500  microns from the scleral spur, anterior chamber angle, angle between sclera and iris and angle between sclera and ciliary processes.

Preoperatively, intraocular pressure was 15.67  ± 0.85  mm Hg, in 2  weeks  – 13.22 ± 0.53  mm Hg, after 1  month  – 13.21 ± 0.55  mm Hg, after 3  months  – 12.42  ± 0.46  mm Hg. Cornealcompensated pressure before surgery was 15.91 ± 0.69 mm Hg, it increased from the first day after surgery, reached maximum  19.37 ± 1.52  mm Hg after 2  weeks and returned to preoperative values at 1  month; in 3  months, corneal-compensated pressure decreased to 14.4  ± 0.70 mm Hg. Goldmann intraocular pressure changes were similar with corneal-compensated intraocular pressure. Mean preoperative aqueous outflow easiness coefficient was 0.15 mmі/min/mm Hg, increased after 2  weeks to 0.24  mmі/min/mm Hg and stayed unchanged in 1 and 3 months after surgery (0.22 mmі/min/mm Hg).

Conclusion: Changes of anatomy and topography of anterior part of the eyeball after cataract phacoemulsification lead to decrease of intraocular pressure by 1.5–2  mm Hg in 3  months after the surgery compared to preoperative values. Further studies of the relation between eyeball anatomy and intraocular pressure are needed.