1. The cause of the ectropion. The active or cicatricial form requires different and more extensive operations than the passive form, such as occurs after facial paralysis, senile ectropion, or that occurring after blepharitis.
2. The degree of ectropion, whether it is partial, affecting merely the lid margin; or complete, affecting the whole lid.
Ectropion of the lower lid is always accompanied by epiphora, owing to the want of application of the canaliculus to the lacus lachrymalis. The canaliculus is also apt to become obliterated as the result of marginal blepharitis. Before undertaking any of the operations described below this condition must be remedied, either by dilating the canaliculus or by slitting it inwards for a short distance (see [p. 290]), otherwise, even if the operation be successful in restoring the deformity, the overflow of tears causes the patient to pull down the lower lid constantly in wiping them away, and this tends to reproduce the condition.
After many of the operations a temporary tarsorrhaphy is required to keep the lid in position during the process of cicatrization. The temporary bands produced by this operation are so placed on either side of the cornea as not to interfere with vision altogether. Canthorrhaphy is also desirable in some cases, especially when the ectropion affects the outer end of the lid.
The deformity to be overcome in ectropion is not only the turning outwards of the lid; in cases which have existed for any length of time the lid border becomes permanently elongated and requires to be shortened before it will keep in position. The exposed conjunctiva, especially in cases secondary to blepharitis, becomes thickened near the lid margin, and, though it may regain a more or less normal appearance after the lid has been replaced in position, the thickened margin frequently prevents the proper apposition of the canaliculus, and in these cases it is often desirable to remove this tissue (see Fergus’s operation).
OPERATIONS FOR PASSIVE ECTROPION
Fig. 148. Snellen’s Sutures.
A. A suture in position.
B. The suture tightened.