On the third day of APAO 2023, experts discussed some complications that can occur after seemingly ‘perfect’ cataract surgery, and what to do about them.
You think things went pretty well with your cataract surgery, but a few weeks later, the patient came back complaining of problems… This can happen. While most patients fully recover after cataract surgery, a small percentage sometimes experience complications.
Visual disturbance after multifocal cataract surgery is very common, and it is very important not to assume that the problem comes from the implanted lens, noted Dr. Choong Yea Fong from Malaysia.
According to him, convergence insufficiency may actually be the issue. The condition is characterized by a decreased ability to converge the eyes and maintain binocular fusion while focusing on a near target.
Thus, doing a proper orthoptic assessment before treatment is crucial when patients complain of symptoms after multifocal surgery. “Some patients are erroneously diagnosed and treated with intraocular lens (IOL) replacement,” he said.
Convergence insufficiency can be treated with conservative treatment (observation for at least three months, monocular occlusion, convergence exercises, and fusion functional training) or surgically (if symptoms persist above six months), which includes lateral rectus recession or medial rectus resection, and mini-tenotomy under topical anesthesia for small angle strabismus with diplopia.
Postoperative cystoid macular edema
Meanwhile, Dr. Harvey Uy from the Philippines described postoperative cystoid macular edema (PCME) as the most common cause of blurred vision after uneventful cataract surgery.
Usually occurring a few months after the operation, the condition is characterized by postsurgical macular thickening/accumulation of fluid within the intracellular spaces of the retina, resulting from perifoveal capillary leakage. Diagnosis is fairly easy. Post-surgery fluorescein angiography (FA) can detect up to 20% to 30% of PCME in patients who have undergone cataract surgery, while optical coherence tomography (OCT) can detect 40%, according to him.
Prevention is always better than cure. “When we see patients with risk factors, it is a good practice to minimize trauma and control uveitis for several months before attempting surgery, which is usually with non-steroidal anti-inflammatory drugs (NSAIDs). Fortunately, the majority of cases resolve spontaneously,” Dr. Uy shared. For cases that don’t, a wide range of therapies is readily available, and a stepladder approach may be appropriate.
Treatments include topical NSAIDs, topical oral acetazolamide, periocular or intravitreal triamcinolone acetonide (which may work better than periocular steroid), intravitreal dexamethasone implant, and intravitreal anti-vascular endothelial growth factors (anti-VEGFs).
“The key thing to remember is, the sooner you give these treatments, the better the outcome. As much as possible, try to give within a month of presentation,” he advised, adding that for stubborn cases, further surgical management may be needed to correct the inciting event, be it a malpositioned IOL, incarcerated vitreous, vitreous adhesions, or retained lens material.
Postoperative diplopia can be a cause of dissatisfaction for patients as well. According to Dr. Thomas Kohnen from Germany, there are five main reasons for postoperative diplopia: diplopia masked by cataract, optical aberrations, dislocated IOL, side effects of local anesthesia, and residual astigmatism.
Diplopia masked by cataract is a severe situation that can be prevented with better preoperative assessment or resolved by performing another surgery. Meanwhile, optical aberrations can be corrected with contact lenses or excimer-laser surgery.
On the other hand, IOL in the wrong position can cause different refractions by light passing through the edge of the optic. The solution is usually to constrict the pupil using pharmacological agents. There are also surgical options, which include a capsular tension ring, IOL/capsular bag fixation, and secondary IOL implantation.
Dr. Kohnen mentioned that anesthesia side effects can be a cause, but it doesn’t usually happen nowadays as most cataract surgeries are performed under topical anesthesia.
Lastly, toric IOL rotation after cataract surgery can cause residual astigmatism. In such cases, he said he would usually wait one to two weeks before repositioning the lens.
Editor’s Note: The 38th Asia-Pacific Academy of Ophthalmology Congress (APAO 2023) was held on February 23 to 26 in Kuala Lumpur, Malaysia. Reporting for this story took place during the event. A version of this article was first published in Issue 4 of the APAO 2023 Show Daily.