Long-term monitoring needed to catch unusual IOL complications
Complications can occur years after the original cataract surgery.
The vast majority of cataract surgeries result in the placement of an IOL within the capsular bag, which is typically the most natural and stable position. For nearly every patient, the IOL will be securely held in position for decades to come, providing excellent visual acuity. However, in some cases there can be complications with IOLs, the most common of which is dislocation of the IOL due to progressive zonular weakness. These cases can be remedied by suture fixation of the IOL to the sclera or even the iris, but what about more unusual IOL complications?
In the cases presented here, the patients had late-stage complications from the original cataract surgery, which was done years prior. We can agree that both of these cases will require a return trip to the operating room to address these complications, but what exactly would be the best course of action?
Case 1: Anterior displacement of IOL optic
A 72-year-old patient presented to our clinic with a history of decreased vision in the left eye for more than 1 year. His vision was 20/400, and he was diagnosed with a full-thickness macular hole as well as a visually significant cataract. Because the cataract precluded a good video of his macula, he underwent cataract surgery as well as a prior pars plana vitrectomy and membrane peeling.
Due to zonular weakness, the surgeons elected to place a three-piece acrylic IOL in the sulcus. Gas was also placed in the vitreous cavity to assist with the closure and healing of the macular hole. The patient did well in terms of retinal healing and closure of the macular hole, and the IOL was well-centered in the sulcus.
The patient returned 1 year later with anterior displacement of the IOL optic and a dense fibrotic posterior capsule (Figure 1). There was optic-iris capture for 3 clock hours and a low-grade chronic inflammatory process. The patient needed the optic-iris capture resolved and the posterior capsule opened centrally to return the vision to a normal level. This is best done in the operating room and not with a YAG laser in the clinic.
Our approach involved using a small-gauge vitrectomy cutter through the pars plana to create a central 5-mm posterior capsular opening. The IOL was then carefully dissected free and rotated, with the haptics kept in the sulcus but with the optic pushed posterior through the capsular opening. This optic capture through the capsular opening gave us a high degree of stability and security that it would no longer prolapse into the anterior chamber. The patient did well, and the low-grade inflammation completely resolved.
Case 2: Pigment dispersion, iritis, glaucoma
Our patient had LASIK surgery for the treatment of 9 D of myopia about 20 years ago. The results were good for many years, but eventually she developed age-related cataracts. Four years ago, the cataract surgery was performed with a single-piece acrylic IOL placed in the capsular bag. The intended refractive goal of the surgery was plano, but the patient ended up with a hyperopic surprise of +2 D. The patient tried to get used to this refraction and even tried wearing a contact lens to correct the eye to plano. After a year, she could no longer tolerate the contact lens due to dry eye issues and sought a surgical solution.
The proposed surgery was piggyback implantation of a three-piece silicone IOL in the ciliary sulcus. The idea is that the rounded edge of this soft silicone IOL would be gentle on the iris. Also, because the patient had a large eye with a long axial length and a deep anterior chamber, it was assumed that the piggyback IOL would work well. Initially, the patient had a great visual result with a near plano outcome; however, this was short-lived. She presented to our clinic with chronic iritis, glaucoma and pigment dispersion in this eye only (Figure 2).
The patient had iris transillumination defects for a full 360°, matching where the piggyback IOL optic edge was scraping the posterior surface of the iris. This caused pigment dispersion, which was seen on gonioscopy, as well as chronic low-grade iritis. Her IOP was moderately elevated but responded well to topical pharmacotherapy. There was also significant posterior capsule opacity and growth of lens epithelial cells. Again, we elected to avoid treating with a YAG laser and instead returned to the operating room.
The sulcus-based silicone IOL was easily explanted, and then the acrylic IOL was carefully dissected out of the capsular bag and removed. The posterior capsule was gently vacuumed using the irrigation and aspiration probe, and most of the lens epithelial cells and capsular opacities were removed. A new IOL with an appropriate dioptric strength, combining the powers of both the old acrylic and silicone IOLs, was implanted into the capsular bag. The patient healed well from the surgery with complete resolution of the inflammation and excellent vision. There is still a mild elevation of the IOP, which requires treatment with topical medication.
These two cases illustrate that we must continue to monitor our IOL patients into the future, particularly in unusual cases. When we are combining cataract surgery with a pars plana vitrectomy involving gas placement, placement of the IOL in a more secure position is preferred. In-the-bag placement with a smaller capsulorrhexis is ideal, and if sulcus placement is desired, then optic capture through the capsulorrhexis is recommended. For piggyback IOLs, keep in mind that the potential for complications exists and that often an IOL exchange would be a better option.