Kuhnt’s operation (modified). The object of this operation is the removal of a triangular piece of conjunctiva and tarsal cartilage from the centre of the lower lid, the base of the triangle being placed towards the free margin of the lid so as to produce sufficient shortening of the elongated lid border to hold it in position. The skin of the lid is also shortened by removal of a triangular portion at the external canthus.
Indications. It is especially suitable for cases of paralytic ectropion (lagophthalmos) and severe degrees of senile ectropion of the lower lid.
Instruments. Lid spatula, Beer’s knife, scissors, forceps and sutures.
Operation. A general anæsthetic is required.
First step. The lower lid being held between the finger and thumb is split in the intermarginal line along the outer two-thirds of its length, and the incision deepened till the lower border of the tarsus is reached. For this purpose some surgeons use a broad keratome instead of a Beer’s knife.
Second step. A triangular piece of conjunctiva and the whole thickness of the tarsus are removed from the centre of the lower lid, the base of the triangle being towards the free margin of the lid and being of sufficient length to produce the shortening desired to bring the lid up into position (Fig. 150); this is best estimated by making the incision forming the inner limb of the V and overlapping the outer flap until the lid is pulled upwards into position.
Third step. A triangular piece of skin with its base upwards is excised from the outer canthus in the following manner (Fig. 150). An incision is made outwards and slightly upwards from the canthus. A vertical incision, twice the length of the preceding one, is made directly downwards from its outer end to the outer canthus, and the lower end of this is then joined by an incision completing the triangle. The skin marked out by this triangle is then dissected up and removed. The undermining of the flap formed by the skin and subcutaneous tissue of the outer part of the lid is continued inwards until the flap, when pulled up into place, restores the lid to its proper position.
| Fig. 150. Modified Kuhnt’s Operation for Severe Ectropion. Second step. The outer half of the lid is split and a V-shaped portion of the tarsal plate removed. The triangular piece of skin at the outer canthus is entirely removed. | Fig. 151. Modified Kuhnt’s Operation. Fourth step. Showing the sutures in position. The outer part of the lid has been undermined and dissected up. The V-shaped gap in the tissues is sutured first. |
Fourth step. The lid is sutured into position. The V-shaped wound in the conjunctiva and tarsus is sutured, the knots being placed on the conjunctival surface with the exception of the suture at the lid border, which is turned the other way, the ends being brought out through the skin of the outside flap, after the latter has been sutured in position, and the two ends tied over a bead. The outside flap of skin is brought up into position by a suture at its upper angle. As the result of this a few eyelashes project beyond the outer canthus; these should be excised. Additional sutures to hold the flap in position are then inserted. Both eyes should be bandaged after the operation, otherwise the knots in the conjunctiva may rub on the cornea.
Argyll Robertson’s operation. The operation aims at shortening the border of the lower lid and at the same time pulling it upwards into position by means of a strap of skin and subcutaneous tissue cut from the outer side, the attached end of the strap being formed by the outer portion of the skin of the lower lid.