ULTRASOUND
BIOMICROSCOPY AND FILTERING ZONE RECONSTRUCTION AFTER GLAUCOMA SURGERY
Khristo P. Takhchidi, Dmitri I. Ivanov, Nikolai
V. Strenev
Bardin Str. 4a Ekaterinburg, Russia
We've performed ultrasound biomicroscopy (UBM) in
100 eyes 1 week to 10 years after glaucoma surgery: 34 with normal IOP (Group
1) and 66 with high IOP (Group 2).
In Group 1 outflow pathways were seen at the
intrascleral level; an intra- or episcleral cavity with indistinct contours (29
eyes) or a diffuse medium-reflective bleb with conjunctival microcysts (5 eyes)
were found. In Group 2 3 variants were distinguished: a) an intrascleral
fistula and a low-reflective subconjunctival cavity (Tenon's cyst) - 27 eyes;
b) intrascleral fistula and a cavity differing from Group 1 by sharp, high-reflective edges - 16
eyes; c) no signs of filtration - 23 eyes. Subgroups 2a and 2b were estimated
as partial obliteration of outflow pathways (at conjunctival level - 2a; at
episcleral level - 2b). Opening of cavity wall with a specially designed
spatula-knife or a diamond microblade was performed with efficacy of 81% and
75%, respectively. In absence of
effect repeated glaucoma surgery was performed in another segment of the
eyeball (as well as in 2c subgroup with complete obliteration of outflow
pathways at intrascleral level).
Thus, UBM signs of complete or partial obstruction
of outflow pathways and three levels of obstruction (conjunctival, episcleral
and intrascleral) were distinguished. In IOP decompensation outflow pathways
were partially patent in 65% of cases. The technology of filtering zone reconstruction provides high
efficacy. Taking into consideration its simplicity and safety, it could be
recommended for wide clinical use. In failed reconstruction, as well as in
complete outflow pathways obliteration, repeated glaucoma surgery is indicated.