Today and tomorrow we are featuring cases with congenital colobomas where there is an absence of part of the iris and zonules in the characteristic inferior portion of these tissues. For this case, how would you secure the IOL for good long-term stability? And would you suture the iris and perform a pupilloplasty or would you leave it as is?
Over 25 years ago I did a congenital coloboma that looked just like that at the end of the case. The next day the pupil was small and pulled inferiorly. The reason for the decentration was neglecting to address the sphincter muscle in the sides of the iris coloboma. That same case I took back to the OR and removed the colobomatous sphincter before re suturing. The results were dramatically better.
Here is the citation for the publication of the technique, with video: Ogawa GSH. Congenital iris coloboma repair with excision of colobomatous sphincter muscle.
J Cataract Refract Surg. 2021 Aug;47:1088-91. doi:10.1097/j.jcrs.0000000000000440
Publish before Print: 2020. https://doi.org/10.1097/j.jcrs.0000000000000440
thank you for sharing that great teaching point
When there is a colobomatous zonule defect, a broad based capsular tension hook (like the MST) works well for keeping the vitreous from prolapsing during the phaco. The nucleus is not always prlapsable, and blind placement of a CTR is not always optimal.
Surgical knots have one or more wrap for each throw. The knot that Amar Agarwal has been popularizing is a single throw, four wrap Seipser knot. Dr. Agarwal uses a misnomer by calling a wrap a throw. The actual name for that knot is a single throw four wrap Seipser knot. It works when there is good tissue compression, such as iris within the pass.