Sulcus Lens Implant Location
A sulcus lens implant is located in the ciliary sulcus, which is the anatomical space between the posterior surface of the iris base and the anterior surface of the ciliary body in the posterior chamber of the eye 1.
Anatomical Position
The ciliary sulcus represents a specific anatomical landmark in the eye's posterior chamber:
- Anterior boundary: Posterior surface of the iris base
- Posterior boundary: Anterior surface of the ciliary body
- Location: Posterior chamber (behind the iris, in front of the natural lens capsule or capsular bag remnant)
This space is distinct from the capsular bag, which is the preferred location for most modern IOL implantations 2.
Clinical Context for Sulcus Placement
When piggybacking two posterior chamber IOLs is indicated (such as in extreme hyperopia requiring IOL power beyond available range), it is highly preferable to place one IOL in the capsular bag and one in the sulcus to reduce the risk of interlenticular membrane formation 2.
The sulcus serves as an alternative implantation site when:
- The capsular bag is compromised or ruptured during surgery
- Posterior capsule rupture occurs intraoperatively
- Supplementary refractive correction is needed with add-on lenses
- Primary capsular support is inadequate 3, 4
Important Design Considerations
Critical caveat: Not all IOLs are designed for sulcus placement. Toric lenses available in the United States are specifically designed for implantation within the capsular bag, not the sulcus 2. Three-piece IOLs or one-piece PMMA lenses are the most appropriate options for sulcus placement, while single-piece acrylic IOLs are not designed for this location and carry risk of chronic complications including pigment dispersion, IOP elevation, and UGH syndrome 3, 4.
The sulcus sits approximately 0.5-1.0 mm more anterior than the capsular bag, which affects IOL power calculations and effective lens position 3.