Cysts of Tenon's capsule following filtration surgery. Medical management
M. B. Sherwood, G. L. Spaeth, S. T. Simmons, D. A. Nichols, A. M. Walsh, W. C. Steinmann and R. P. Wilson
Department of Ophthalmology, University of Florida, Gainesville 32610.
Cysts of Tenon's capsule (encapsulated blebs) developed postoperatively in
77 (13%) of 607 eyes that underwent filtration surgery between 1980 and
mid-1985. The annual incidence was not uniform, increasing markedly
throughout the period. Seventy-four eyes were treated with medical therapy
only. At a mean follow-up of 19 months, the success rate for these eyes,
defined as an intraocular pressure (IOP) of 21 mm Hg or less, was 92%. The
three eyes that underwent surgical revision subsequently failed clinically
by the study criteria. Those patients in whom cysts of Tenon's capsule
developed were compared with an age-matched control group to assess for
possible differences in long-term outcome. There was a significantly higher
IOP in the Tenon's cyst group at one and three months after surgery, and an
increased proportion of IOPs above 30 and 40 mm Hg. At a six-month and
later follow-up, there was no significant difference in the mean IOP or in
progression of visual field loss. Causative factors were sought for the
development of these cysts of Tenon's capsule. Prior conjunctival surgery,
or previous cyst formation in the other eye, were the significant risk
factors noted.
