What intraocular lens can be sulcus fixed?

Any IOL placed in the ciliary sulcus should have sufficient posterior iris clearance and secure fixation. Choice is therefore between a 3-piece foldable PCIOL IOL and a PMMA IOL.

A 3-piece foldable PC IOL has the advantage of thin, posteriorly angulated C-shaped haptics that does not contact the iris. Ideally, the anterior optic surface should be smooth and have rounded edges to minimize iris chafing and the overall IOL length should be at least 13.5 mm. Capturing the IOL through the capsulorrhexis is recommended and will ensure good centration. Because of the risk of retinal detachment with posterior capsule rupture and vitreous loss, silicone intraocular lenses are better avoided as they may compromise the view should vitrectomy surgery become required. With capsulorrhexis capture, the same IOL power calculated for capsular bag fixation can generally be used. However, should this not be feasible, the lens optic will have more anterior location and the lens power should be reduced by 0.5 to 1.0 D.

A large diameter (>13.5 mm) PMMA PC IOL is another option but the incision will need to be enlarged to at least 6.5 mm which is not desirable.

Single piece acrylic lenses are not recommended for ciliary sulcus placement.1 The haptics are thick and not posteriorly angulated and will therefore contact the posterior surface of the iris when implanted in the sulcus. Furthermore, the overall loop-to-loop dimension of these lenses is only 13.0 mm or less which is short for many eyes. The square edge optic design increases iris chaffing.

In eyes with insufficient capsule support, the surgeon has the choice between iris- or scleral-sutured PC IOLs and open loop AC IOLs. The American Academy of Ophthalmology Technology Assessment study reviewed more than 40 papers that addressed the outcomes of IOLs implanted without adequate capsule support and carried evidence rating of level III or higher. 2 The study was unable to find a significant difference in the safety or efficacy of these 3 methods and therefore use of any of these modalities is appropriate and is left to the discretion of the surgeon.

References:

1 Complications of sulcus placement of single-piece acrylic intraocular lenses: recommendations for backup IOL implantation following posterior capsule rupture. Chang DF, Masket S, Miller KM, et al; ASCRS Cataract Clinical Committee. J Cataract Refract Surg. 2009 Aug;35(8):1445-58.


2  Intraocular lens implantation in the absence of capsular support; a report by the American Academy of Ophthalmology (Ophthalmic Technology Assessment). Wagoner MD, Cox TA, Ariyasu RG, Jacobs DS, Karp CL. Ophthalmology 2003; 110:840–859

Ahmed Sallam
Consultant Ophthalmologist

Gloucestershire Eye Unit, UK