Background: The seton implant has been shown useful for treatment of
glaucoma for over 200 years. There
has been a wide variability of reported success rates. This may be related to varying criteria
of a successful outcome, differing follow-up lengths, and difficulties in
quantifying the preoperative condition of the eye.
Methods: The authors studied the long-term results of various
glaucoma implant devices. A
retrospective review of 70 eyes, with a minimum of 5 years’ follow-up was
performed. A variety of shunts
were included: Molteno, Baerveldt, and Ahmed. Age, sex, race, visual acuity, underlying diseases,
previously performed surgeries, ocular diagnosis, intraocular pressure, and
number of glaucoma medications taken were evaluated to establish factors
influencing long-term surgical outcome.
The criteria for success include a reduction of intraocular pressure by
at least 30% of baseline, without chronic hypotony. Anyone who required additional surgeries, had a decline in
visual function, or some other ocular catastrophic event was considered a
failure. Post-operative variables
examined include: visual acuity,
intraocular pressures, number of glaucoma medications taken, intra-operative
and post-operative complications, and typically ocular surgeries. The most frequently encountered
complications include: vitreous
hemorrhage, inadequate intraocular pressure lowering, corneal opacification,
and decreasing visual acuity.
Conclusion: Glaucoma is often a chronic disease. Although the intraocular pressure can
initially be reduced with implant devices, the long-term complications may
cause significant reduction of visual acuity. Establishing the long-term survival curve for a surgical
procedure such as a tube shunt may be invaluable.