Transscleral fixation of a malpositioned IOL is a common procedure; however, it can be difficult to perform. During scleral fixation, the surgeon must work directly in the sulcus. Because it is impossible to observe the sulcus through an operating microscope, most surgeons use indirect scleral landmarks for its location. In reality, sulcus position varies among patients and is not always easily located. This is one of the main reasons for IOL malposition following transscleral fixation.
When suturing, it is important to justify the position of the IOL haptic. The ideal position for the haptics is when they are positioned in the ciliary sulcus (Figure 1). In some instances, the IOL haptic may be decentered in the sulcus and instead located anteriorly or posteriorly to the sulcus (Figure 2). These IOLs may be tilted because the suture did not pass through the sulcus, but rather through some other part of the ciliary body (eg, the pars plana).
The most detrimental complications that can occur during transscleral suturing are postoperative decentration and/or tilting of IOLs. Other common complications include hyphemas, hemophthalmus, corneal edema and retinal detatchment. I have found that the endoscopy — allowing for direct visualization of the sulcus and needle insertion point — combined with ultrasonic biomicroscopy produces fewer of these complications.1 The major advantage of this technique is that there is less chance of postoperative decentration and/or tilt of the IOL.
Endoscopy, Biomicroscopy
I recommend initiating the endoscopic approach with an ultrasonic biomicroscopy to locate abnormalities in cases of malpositioned IOLs. Figure 3 demonstrates the use of electronic microscopy to identify transverse and oblique tissue bands in the ciliary sulcus. These bands can interfere with the lens haptics and dislocate the lens. These bands can be clearly seen through the endoscope. Other examples of abnormalities include posterior synechiae, irido-ciliary angle smoothening, residual cortical material and capsular remnants (Figure 4). Abnormal-ities such as those mentioned above are clearly seen during ultrasonic biomicroscopy. When discovered, the surgeon may avoid these areas in the hopes that the lens will not dislocate postoperatively.
There are two methods to the endoscopic approach. In the first (bimanual method) an endoscopic probe/handpiece enters through either the corneal or scleral paracenthesis. During this method, the surgeon holds the instrument in one hand and penetrates the scleral wall with the other. At all times, you can see the ciliary sulcus on an endoscope screen much like that of a television screen.
There is a downside to the bimanual method; it is very hard to coordinate both hands' movements and to view where your tips are exactly located during the surgery. That is why we created a second method, where a needle is attached (by a silicone sleeve) to the endoscopic probe/handpiece (Figure 5). Therefore, the needle and point of penetration are viewable on the endoscope screen (Figure 6). This direct visualization provides the correct position of the suture and correct position of the IOL in the postoperative period, which is the most important thing.
Positive Results
I have been using the endoscopic technique for about 4 years and the results have been positive. When using the bimanual endoscopic method, the surgeon may use either the ab externo or ab interno approach, however, they are difficult because they are not comfortable for the surgeon. For this reason, I suggest using the one-handed technique.
Several complications (eg, bleeding and corneal edema) occur in both the endoscopic approach as well as the traditional approach to scleral IOL fixation. For the most part, however, these complications are reduced with endoscopy because it does not induce extra manipulation in the eye.
There is a learning curve associated with the endoscopic approach. The image on the endoscopy screen is flat. The surgeon is familiar with having a stereoscopic view (providing depth of focus) when looking through an operating microscope. For this reason, the surgeon must get acquainted with landmarks that signify the distance from the tissue. The ciliary sulcus is nonuniform and oval. The surgeon must keep this in mind when performing the surgery.
I first publicly presented the endoscopic approach for transscleral suturing of malpositioned IOLs in Lisbon, during the European Society of Cataract and Refractive Surgeons meeting.2 Some surgeons have visited our clinic to observe this approach. Its popularity will continue to grow, as the one-handed endoscopy significantly reduces the risk for complications and is superior to the traditional technique.
Boris Malyugin, MD, PhD is from the S. Fyodorov Eye Microsurgery Complex State Institution, in Moscow, Russia. Dr. Malyugin is a member of the CRSToday Europe Editorial Board. He may be reached at malyugin@online.ru.
Up Front | Mar 2006
For Transscleral Suturing: Try an Endoscopic Approach
This technique for malpositioned IOLs may cause fewer complications than traditional transcleral suture techniques.
Boris Malyugin, MD, PhD
