val flap, are elements which enter into the ultimate success or
failure of the procedure.

Aside from the dangers incident to a wide incision in the neighborhood
of the ciliary body and the possibility of accident to the lens or
vitreous body, or of intra-ocular hemorrhage, there is for the average
operator the added difficulty and danger in removing a piece of sclera
of the exact size required. The technique of the operation is even more
difficult and exacting than in the performance of the trephine
operation, and it also compares unfavorably in safety.

The advisability of removing the conjunctival flap, as advocated by Dr.
Wood, as a modification of the Lagrange operation, may be seriously
questioned, for aside from the fact that apparently no advantages in
aiding permanent filtration are added, there is, added to the objections
to the Lagrange operation already mentioned, the very serious
disadvantage of subjecting the area at the root of the iris to infection
for a prolonged period of time. The advantages of the protection
afforded by a conjunctival flap far outweigh the disadvantages of a
remotely possible interference of drainage by the blocking of the open
wound with conjunctival tissue. The fortunate experience of Dr. Wood in
not having infection in a wound which remains open and unprotected for
variable lengths of time is not likely to be the experience of any
considerable number of operators, and probably will not always be the
experience of Dr. Wood. Furthermore, the possibilities of damage by
hemorrhage from the choroidal or retinal vessels, delayed formation of
the anterior chamber and adhesion of the capsule of the lens to the
wound, and the injurious effects of even slight trauma subsequent to the
operation, including loss of vitreous, are increased by omitting the
conjunctival flap.

The modern operation for the relief of glaucoma, by which a filtering
scar is produced which permits escape of liquid from the anterior
chamber, is the one which apparently holds out the most hope of
permanently relieving the condition. While success will depend always to
a certain extent upon the personal equation, yet it seems now that for
a large majority if not all of the cases we are justified in abandoning
all other operations than trephining, notwithstanding the verdict of
Elschnig and others that fistula forming operations eventually will be
discarded in favor of iridectomy and cyclodialysis.

Late or secondary