**9. Scleral-fixated intraocular lens**

Scleral-fixated intraocular lenses have gained popularity for secondary IOL implantation in patients with aphakia. They are indicated in patients who do not wish to remain aphakic and have no capsular or iris support. However, some surgeons prefer SFIOLs even if there is iris support. In patients where an ACIOL might not be a good option such as in patients with corneal endothelial disease or glaucoma, SFIOLs or IFIOLs are both viable options.

Scleral-sutured intraocular lens implantation started in the 1980s with abinterno and ab-externo approaches. Ab-interno approaches utilized suture passes from inside to outside the eye in a blind maneuver. This led to complications with retinal detachment, vitreous hemorrhage, and unpredictable haptic placement. Ab-externo approaches were found to be more promising with sutures passed from outside to inside the eye. This led to more reliable suture placement. Lewis popularized an ab-externo technique in 1991 [21] whereby 10-0 polypropylene

suture was placed 2 mm posterior to the limbus and then "docked" into a 28-gauge straight needle 180 degrees away to externalize the needle. The suture that remained inside the eye was brought out through the corneal incision and cut. The suture ends were then tied to the IOL haptics and the IOL was inserted into the eye for sulcus placement. The external sutures were then tied down to the adjacent sclera. Ten-year follow-up of thirteen eyes showed only two eyes had minimal decentration although it did not affect final visual acuity [22].

Since Lewis described his technique, newer lenses and sutures have further improved ab-externo techniques. Lenses such as the CZ70BD (Alcon, Fort Worth, TX), enVista MX60 and the Akreos AO60 (Bausch and Lomb, Rochester, NY) have eyelets for suture fixation, which improve lens stability. Most prior scleral suturefixed techniques used 10-0 polypropylene. However, several studies have described 10-0 polypropylene late suture breakage [23–25]. These reports show late breakage of 10-0 polypropylene suture up to 8 years post-placement. Gore-tex sutures have been used outside the eye with notable long-term stability. Studies with up to 3 years follow-up have shown Gore-tex suture durability within the eye. Similarly, 9-0 polypropylene has been shown to have improved suture stability compared to 10-0 polypropylene but with only short-term follow-up. Long-term studies are needed to further evaluate if these sutures continue to avoid suture breakage.

Bausch & Lomb Akreos AO60 hydrophilic acrylic lens contains 4 eyelets allowing 4 point fixation. However, these lenses undergo calcification and opacify when in contact with intraocular gas or air [26]. Given that aphakic patients often have coincident retinal pathology and might be at increased risk for retinal detachment repair this might be an important consideration when deciding on the optimal lens and fixation technique. The Bausch & Lomb enVista Mx60 IOL is made of hydrophobic acrylic and does not opacify when in contact with gas or air. However, it has only 2 eyelets for fixation at the haptic-optic junction.

#### **9.1 Scleral fixation of IOL with Gore-tex suture technique**

Typically, conjunctival peritomies are performed where the sclerotomy sites are planned, 180 degrees apart. Sclerotomy placement at horizontal, oblique and vertical orientations are all acceptable. A toric lens marker is used to mark the axis of the lens within the peritomy. Sclerotomy sites are marked, 3 mm posterior to the limbus and 4–5 mm apart from each other in each scleral bed. One of the suture sclerotomy sites can be used for the vitrectomy trocar. The trocar sclerotomy should be made perpendicularly without tunneling to facilitate suture knot insertion. The lens is pre-threaded with a suture on each side and inserted into the eye. The sutures are then externalized using forceps through the sclerotomies taking care not to tangle the sutures. To avoid suture tangling and disorganization, the sutures can be inserted into the eye and externalized prior to lens insertion. The sutures are then tied down permanently with care taken to make sure the suture tension allows the lens to be appropriately centered. The knot is then buried into the sclerotomies to avoid knot erosion through the conjunctiva. The conjunctiva is sewn in place over the sclerotomies and sutured. Long term follow-up results are yet to be determined. Two-year results have shown good lens and suture stability with the Gore-tex suture. Complications include hypotony (up to 10%) with and without serous choroidal detachment. This is thought to occur from leakage from the sclerotomy sites. Vitreous hemorrhage and hyphema have also been reported. Published studies have not reported persistent post-operative inflammation, endophthalmitis or suture erosion/breakage at 2 years [27]. With in-the-bag calculations for the IOL, a recent study showed that 2 mm sclerotomies resulted in a more myopic post-operative

**129**

*Secondary Intraocular Lens*

tucking [31].

*DOI: http://dx.doi.org/10.5772/intechopen.89569*

in-the-bag IOL calculations [29].

outcome than 3 mm sclerotomies [28]. Other studies have shown acceptable refractive outcomes with this technique and 3 mm from the limbus sclerotomies with

Sutureless techniques have also been developed to avoid potential complications that can rise from suture fixation including knot erosion, endophthalmitis, and suture breakage. Agarwal described scleral fixation with glued haptic fixation [30]. Scleral flaps are created 180 degrees apart and a sclerotomy is made within the flap. The haptics of a 3-piece IOL are then externalized via the sclerotomy and glued into place with the flap closing over the haptic. Several complications can occur with the haptic including extrusion, dislocation, and breakage. Haptic-related complications seen include haptic extrusion, haptic dislodgement, broken haptic and subconjunctival haptic. Most of the haptic-related complications are due to improper scleral

Yamane et al. described a technique whereby three-piece IOL haptics are passed through a 27 gauge needle which guides the haptic through a tunneled sclerotomy [32]. The externalized haptic is than cauterized to create a bulb at the tip of the haptic to allow for improved stability within the scleral tunnel. Short-term outcomes from Yamane's initial study reported no IOL dislocation at 1.5 years. Reported complications include optic capture of the iris (8%), vitreous hemorrhage (5%) and cystoid macular edema (1%). It is important to note that the Yamane technique utilizes the EC-3 PAL three-piece intraocular lens, which has more durable and malleable haptics compared to the 3-piece IOLs commonly used in the United States. Higher rates of IOL dislocation have been reported with the Yamane technique when non-EC-3 PAL 3-piece IOLs are used. Several modified Yamane techniques have been since described including the use of 27 gauge trocars instead of a needle to externalize the haptics. Long-term follow-up has yet to be presented since these

Baron was the first to implant an anterior chamber IOL in 1952 [33]. Several other ACIOLs followed during the 1950s but were limited by their design and anterior vault that led to high rates of corneal decompensation. Closed loop ACIOLs

A peripheral iridectomy is required as ACIOLs can cause pupillary block glaucoma. Compared to other IOL techniques, the ACIOL requires a larger six-millimeter incision. Typically, a scleral tunnel is formed in order to minimize astigmatism from a clear corneal incision. Contraindications for anterior chamber intraocular lens include corneal decompensation, angle abnormalities with or without glaucoma, and lack of iris support. Complications associated with ACIOL implantation include endothelial failure with corneal edema, chronic intraocular inflammation,

gained popularity in the 1970s due to their various flexible designs that were thought to alleviate problems with sizing. However, the sharp edges of the closedloop ACIOL haptic eroded uveal tissue, released inflammatory mediators, and led to multiple complications including uveitis-glaucoma-hyphema syndrome, corneal decompensation, and cystoid macular edema [34–37]. Open-loop ACIOL designs were introduced in the 1980s and their design continued to be improved with its use peaking in the 1990s. These modern open-loop ACIOL designs appear to have less

**9.2 Sutureless scleral fixation intraocular lens implantation**

techniques have only been introduced in the past decade.

**10. Anterior chamber intraocular lens**

associated complications.

*Intraocular Lens*

suture was placed 2 mm posterior to the limbus and then "docked" into a 28-gauge straight needle 180 degrees away to externalize the needle. The suture that remained inside the eye was brought out through the corneal incision and cut. The suture ends were then tied to the IOL haptics and the IOL was inserted into the eye for sulcus placement. The external sutures were then tied down to the adjacent sclera. Ten-year follow-up of thirteen eyes showed only two eyes had minimal decentration

Since Lewis described his technique, newer lenses and sutures have further improved ab-externo techniques. Lenses such as the CZ70BD (Alcon, Fort Worth, TX), enVista MX60 and the Akreos AO60 (Bausch and Lomb, Rochester, NY) have eyelets for suture fixation, which improve lens stability. Most prior scleral suturefixed techniques used 10-0 polypropylene. However, several studies have described 10-0 polypropylene late suture breakage [23–25]. These reports show late breakage of 10-0 polypropylene suture up to 8 years post-placement. Gore-tex sutures have been used outside the eye with notable long-term stability. Studies with up to 3 years follow-up have shown Gore-tex suture durability within the eye. Similarly, 9-0 polypropylene has been shown to have improved suture stability compared to 10-0 polypropylene but with only short-term follow-up. Long-term studies are needed to further evaluate if these sutures continue to avoid suture breakage.

Bausch & Lomb Akreos AO60 hydrophilic acrylic lens contains 4 eyelets allowing 4 point fixation. However, these lenses undergo calcification and opacify when in contact with intraocular gas or air [26]. Given that aphakic patients often have coincident retinal pathology and might be at increased risk for retinal detachment repair this might be an important consideration when deciding on the optimal lens and fixation technique. The Bausch & Lomb enVista Mx60 IOL is made of hydrophobic acrylic and does not opacify when in contact with gas or air. However, it has

Typically, conjunctival peritomies are performed where the sclerotomy sites are planned, 180 degrees apart. Sclerotomy placement at horizontal, oblique and vertical orientations are all acceptable. A toric lens marker is used to mark the axis of the lens within the peritomy. Sclerotomy sites are marked, 3 mm posterior to the limbus and 4–5 mm apart from each other in each scleral bed. One of the suture sclerotomy sites can be used for the vitrectomy trocar. The trocar sclerotomy should be made perpendicularly without tunneling to facilitate suture knot insertion. The lens is pre-threaded with a suture on each side and inserted into the eye. The sutures are then externalized using forceps through the sclerotomies taking care not to tangle the sutures. To avoid suture tangling and disorganization, the sutures can be inserted into the eye and externalized prior to lens insertion. The sutures are then tied down permanently with care taken to make sure the suture tension allows the lens to be appropriately centered. The knot is then buried into the sclerotomies to avoid knot erosion through the conjunctiva. The conjunctiva is sewn in place over the sclerotomies and sutured. Long term follow-up results are yet to be determined. Two-year results have shown good lens and suture stability with the Gore-tex suture. Complications include hypotony (up to 10%) with and without serous choroidal detachment. This is thought to occur from leakage from the sclerotomy sites. Vitreous hemorrhage and hyphema have also been reported. Published studies have not reported persistent post-operative inflammation, endophthalmitis or suture erosion/breakage at 2 years [27]. With in-the-bag calculations for the IOL, a recent study showed that 2 mm sclerotomies resulted in a more myopic post-operative

although it did not affect final visual acuity [22].

only 2 eyelets for fixation at the haptic-optic junction.

**9.1 Scleral fixation of IOL with Gore-tex suture technique**

**128**

outcome than 3 mm sclerotomies [28]. Other studies have shown acceptable refractive outcomes with this technique and 3 mm from the limbus sclerotomies with in-the-bag IOL calculations [29].
