In patients with Marfan syndrome with severe lens dislocation, posterior chamber IOL suture fixation is a necessary treatment. In recent years, with the improvement of surgical techniques and the progress of surgical equipment, personalized surgical plans for such patients with lens subluxation are also constantly improved, hoping to provide a better guarantee for the maximum recovery of patients' visual function.
The traditional two-point scleral fixation method requires a relatively large corneal incision,which make postoperative outcomes unpredictable[6, 7].Canabrava et al. have introduced a four-flanged intrascleral IOL fixation technique with 5 − 0 polypropylene that does not require flap creation, suture knots, or glue. In their research, an IOLwith fixation holes in the two haptics is used.After one thread passes through the fixed hole, the two ends are respectively fixed on two points of the sclera. Another type of four-point fixation is formed, but the IOL is still two-point fixation.
We use the Akreos AO (Bauus & Lomb) IOL which has four pre-formed closed holes within its haptics. The 7 − 0 polypropylene sutures were passed through four small holes in the eyelet to fix the IOL on the four points of the sclera, making it very stable. The Akreos AO is a hydrophilic acrylic monolithic foldable IOL. There is no worry of breaking the eyelet. It can be implanted from a transparent corneal incision without sutures,which is conducive to a smoother and safer operation. There is less astigmatism and quick recovery of vision after surgery.Our surgery method looks very similar to Sergio, but it is not. Sergio puts the suture through the four loop holes of the IOL outside the eye, and then folds the lens and sends it into the eye.The IOL of the four loops occupies a relatively large space. When the IOL is put on the sutures and then folded and pushed into the eye, it is easy to cause the sutures to wrap around the lens loops, which is not easy to loosen in the narrow space of the anterior chamber. Surgery becomes complicated and the operation duration is prolonged. In our study, the IOL was first pushed into the anterior chamber, and the rest of the operation was actually four repetitions of inserting the needle and guiding the suture. Each operation was only around one loop of the intraocular lens, and there was no such entanglement troubles. The operation is simple and time-saving.
Two possible complications of our technique include damage to the the corneal endothelium or endophthalmitis. Once the corneal endothelium is damaged, serious complication may occur, such as corneal decompensation. In order to avoid this, do not directly use the needle to go through the loop hole of the IOL after entering the anterior chamber. It is recommended fixing the needle, using intraocular forceps to clamp the loop of the iris IOL and passing it through the 30G needle. In our study with a mean follow-up time of 3 months, there were no cases of postoperative infection. However, we acknowledge that endophthalmitis is a concern and has been reported at 1 month and 5months after transscleral fixation of a PC IOL.
When prolapsed vitreous was present in the anterior chamber, anterior vitrectomy was performed. It is imperative to perform an anterior vitrectomy if there is vitreous prolapse with IOL incarceration to release the PC IOL from vitreous adhesions, thereby preventing further vitreous traction with IOL manipulations that may lead to peripheral retinal tears and subsequent retinal detachment.
All operations were completed successfully. Comparing final CDVA (4.12 ± 0.928 logMAR) following fixation to the CDVA prior to the surgery(3.36 ± 0.886 logMAR) showed a statistically difference(t = 0.660,p = 0.029). The CDVA on the last visit was 4.48 ± 0.736 logMAR, compared with the first day after surgery, due to the recovery of corneal edema in some patients, the visual acuity has improved, but the difference is not statistically significant (t = 0.332,p = 0.249). After the operation, elevated IOP above 25 mmHg 4h after surgery was recorded in 6 eyes (40.0%), the IOP normalized within a week in all cases. Cystoid macular edema (CME) was seen in 2 eyes (13.33%), in both cases the CME resolved within a few months with topical standard treatment. Vitreous hemorrhage, and flange exposure were seen in one eye each, corneal edema and anterior chamber inflammation were seen in 4 eyes each (Table 1). The IOLs wer e centered without tilt and decentration.
In conclusion, in this study, we found that patients who had intrascleral four-flanged technique for PC IOL fixation experienced a low incidence of complication with excellent visual outcome. This technique is a simple, effective, and safe method for lens dislocation with Marfan syndrome.