Procedure addresses challenges of leaking incisions and anterior chamber instability
An important advance for enhancing the ease and safety of paediatric cataract surgery is 1.8 mm coaxial microincision cataract surgery (C-MICS) using a particular phaco platform (Stellaris Vision Enhancement System, Bausch & Lomb), according to Dr Balaji Gupta. Dr Gupta says 1.8 mm C-MICS addresses two major challenges in paediatric cases: leaking incisions and anterior chamber instability.
Incision leakage is a particular problem in paediatric eyes because of the elasticity of the young cornea. Intraoperatively, the leaking incision promotes trampolining, which already is an issue in paediatric cases where there tends to be higher posterior pressure associated with use of general anaesthesia and placement of bridle sutures.
"Anterior capsulorhexis is challenging in paediatric eyes because of the elasticity of the anterior capsule," he explained. "Increased posterior pressure and fluctuations in anterior chamber stability compound a difficult situation and make posterior capsulorhexis challenging as well."
Stabilized anterior chamber
With the 1.8 mm incision and its advanced fluidics features (EQ Fluidics and StableChamber, Bausch & Lomb), the phaco platform helps to maintain a stable, deep anterior chamber that enables controlled capsulorhexis.
Several techniques can be used to open the anterior capsule in paediatric surgery, Dr Gupta said. His preference is the two-incision, push-pull technique described by Dr Ken Nischal, in which the capsule is opened initially with two horizontal stab incisions. The distal flap is grasped with forceps and pulled toward the surgeon and the promixal flap is pushed.
"This method reliably creates a consistently sized oval opening and it is much easier and safer when done in the presence of a stable, deep anterior chamber," Dr Gupta confirmed.
Due to the anterior chamber stability present when performing 1.8 mm C-MICS, Dr Gupta said he also is more confident about working near the posterior capsule and is able to perform primary posterior capsulorhexis via an anterior versus a pars plana approach.
"After inflating the bag and thanks to the chamber stability, I actually can perform the posterior capsulorhexis without a vitrector and then implant the IOL," he said. "Since the vitreous is well-formed in paediatric eyes and with the IOL acting as a tamponade, vitreous prolapse is prevented.
"The ability to finish the surgery without a vitrectomy represents an important advantage for decreasing postoperative inflammation and macular traction," he added.
Because of the elastic nature of the paediatric cornea, achieving a watertight closure is difficult when operating through a 2.5–2.75 mm incision, even with suturing. In this case, the 1.8 mm MICS procedure is also an asset because the architecture of a smaller incision favours better postoperative stability and minimizes the risk of incision gape and endophthalmitis.