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Extra care must be taken in unusual cataract cases
Four cases that have the potential for unique and significant complications are presented.
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Sometimes we have a case that presents a particular surgical challenge. These unusual situations require a different approach and often come with the potential for unique or more significant complications.
Retinitis pigmentosa
While retinitis pigmentosa is considered a rare disease, it occurs with enough frequency that every cataract surgeon will encounter it during his career. These patients can develop cataracts at an early stage and with unique challenges. Our goal is to get as much light focused as possible with our cataract surgery in order to maximize the resultant vision from the impaired retina. Patients with retinitis pigmentosa must understand that while cataract surgery may improve their vision, it is typically a modest improvement only because the principal visual issue is the retinal disease.
During cataract surgery, we find that these patients often have very loose or lax zonules, and they have a higher risk of postoperative retinal complications such as cystoid macular edema (Figure 1). These patients may benefit from a capsular tension ring if focal areas of zonular weakness are noted, and a three-piece IOL may afford additional options such as sulcus placement or suture fixation. Postoperatively, prolonged anti-inflammatory agents such as steroids and NSAIDs can help in the treatment or prevention of macular edema.
Figure 1. This patient has retinitis pigmentosa with extensive damage to the retina, a pale optic nerve and attenuated retinal vasculature. Cataract surgery in this eye can be particularly challenging due to the propensity for lax zonules and higher risk of cystoid macular edema.
Figure 2. This patient underwent cataract surgery years ago with sulcus placement of a three-piece IOL that recently became subluxed (left inset). The Siepser knot technique (right inset) was used to suture fixate the haptics of the IOL to the posterior surface of the iris to recenter and secure the optic in position (main picture).
Source: Devgan U
IOL subluxation and re-fixation
While we can achieve excellent long-term fixation of the IOL in most cataract cases, sometimes the lens can decenter and induce visual difficulties. With the IOL securely positioned in the capsular bag, we can typically expect stability for the life of the patient. In cases of pseudoexfoliation or other zonulopathy, the entire capsular bag and IOL complex can become dislodged into the vitreous cavity.
In the case shown in Figure 2, the patient had a cataract surgery performed years ago that was complicated by posterior capsular rupture. A three-piece IOL was placed in the ciliary sulcus, where it functioned well for many years. Recently, after head trauma, the patient noted monocular diplopia, and examination showed that the IOL was subluxed. Three-piece IOL designs are particularly well suited to fixation to the sclera or the iris, and this was the approach used. The IOL optic was centered, and each haptic was sutured to the posterior surface of the iris using the Siepser knot technique. This technique allows intraocular suturing through a single 1-mm paracentesis incision, although the suture material must be retrieved through this small incision. A small pigtail hook was used to accomplish this, and the patient ended up with a well-centered and securely fixated lens with a good visual outcome.
Anterior displacement of the entire cataract
There are congenital conditions such as Marfan syndrome and ectopia lentis et pupillae that can result in such severe zonular weakness and loss that the entire crystalline lens can be found in the anterior chamber of the eye. The patient in Figure 3 had a traumatic cataract with anterior displacement of the entire cataract in front of the iris. There was no doubt that we needed to choose an alternate method for IOL fixation because placement in the capsular bag was out of the question. But how did we remove the cataract?
In this case, the cataract was very dense, and an attempt at phacoemulsification within the capsular bag had the risk of displacing nuclear fragments into the vitreous cavity. Because of the repeated displacement of the cataract forward into the posterior surface of the cornea, the patient had about half of the endothelial cell density that would be expected. This meant that performing phaco in the anterior chamber would lead to more cell loss and possibly induce endothelial failure. A planned extracapsular cataract extraction was performed using a superior scleral incision, and the IOL was securely fixated to the sclera.
Figure 3. This patient had a history of traumatic cataract development years ago and presented with a very mobile lens with severe zonular laxity and loss. The entire lens sometimes prolapsed into the anterior chamber (main picture) but then could be repositioned into the posterior chamber with pupillary dilation (inset picture).
Figure 4. This 25-year-old woman was involved in a car accident in which the deploying airbags caused ocular injury. After the hyphema and inflammation resolved, a temporal dehiscence of the iris with focal zonular loss (inset picture) was noted. Despite these injuries, she had only mild cataract changes and 20/25 vision.
Source: Devgan U
Sometimes it is best to delay surgery
The final case involves a 25-year-old woman who was in a car accident in which the airbags deployed and caused ocular injury (Figure 4). It took about 6 weeks for the hyphema and inflammation to resolve, at which time she was noted to have a temporal dehiscence of the iris for 3 clock hours as well as loss of zonules in that area. While we can address the zonular loss with a capsular tension ring with possible suturing and the iris trauma with re-approximation and suture fixation, at this point the patient had a mild cataract. With her –1 D glasses, she saw 20/25 in this eye with mild lens opacities.
At this point, the patient did not understand that while an IOL could give her good vision, she could not achieve the high degree of accommodation that the crystalline lens provides. Performing the cataract surgery with her vision at the 20/25 level was not the best option. The choice was made to give her a commercially available colored contact lens to block light from entering the area of iris dehiscence and correct her mild myopia. She enjoyed this option for a few months until the cataract worsened to the 20/100 level, at which time cataract surgery and iris reconstruction were performed successfully.
For more information:
- Uday Devgan, MD, is in private practice at Devgan Eye Surgery in Los Angeles and Beverly Hills. He can be reached at 11600 Wilshire Blvd., Suite 200, Los Angeles, CA 90025; 800-337-1969; email: devgan@gmail.com; website: www.DevganEye.com.
- Disclosure: No products or companies are mentioned that would require financial disclosure.