Pseudoexfoliation and Cataract Surgery

Pseudoexfoliation syndrome is characterised by the production and progressive accumulation of fibrillar extracellular material within different ocular tissues, and its incidence varies considerably according to geographical location. Cataract surgery in pseudoexfoliative patients is associated with a higher rate of complications, which are more common the more advanced the cataract. For this reason, the approach in these cases requires a thorough pre-operative study, a carefully planned surgical strategy and appropriate post-operative follow-up, which are the issues discussed in this review. J Emmetropia. 2013; 4: 39-47 First described in 1917 by Lindberg1, pseudoexfoliation syndrome is an age-related disease characterised by the production and progressive accumulation of fibrillar extracellular material within different ocular tissues. According to epidemiologic studies2, it is responsible for 20–25% of open-angle glaucoma, representing the most common known cause worldwide. There is an association between pseudoexfoliation and cataracts, possibly due to ocular ischemia and defective antioxidant defence mechanisms3. Moreover, cataracts appear sooner and progress quicker in these patients4. Like cataracts, the incidence of pseudoexfoliation increases with age5; in the USA, the rate was found to increase from 0.6% at 65 years to 5% from 70 years on6. Cataract surgery in pseudoexfoliative patients has always been associated with a greater number of complications, for some authors7-8 even up to 5 and 10 times greater. However, with new advances, more recent studies have shown this figure to be between 1.5 and 3%9,10, depending on the level of severity and progression of the pseudoexfoliation, which takes us to the first important consideration: Cataract surgery must be performed earlier than in routine cases. Pseudoexfoliation does not concern all surgeons equally, as its incidence varies widely, not only between countries, but also between regions within a country. Thus, the prevalence in Egypt is 39% and in Scandinavian countries is 26%11, contrasting with the 0% prevalence found in Greenland Inuit. In France, while Paris has a prevalence of 3.6%, Brest has 20.6%11. There is also great variation in Spain, with 0.5% in Madrid compared to 20% in Galicia4. CATARACT SURGERY IN A PATIENT WITH PSEUDOEXFOLIATION Why is it a challenging surgery? Mainly because there are two very significant risk factors: 1. Poor pupillary dilation due to the iris ischemia that accompanies the syndrome, as well as the infiltration of extracellular material into the iris, which produces a mechanical obstruction to dilation12 (Figure 1). 2. Progressive zonular weakness that increases in hard cataracts, old age, glaucoma and poor pupillary dilation (Figure 2). Surgical considerations Naturally, the difficulty of the surgery will depend on pupil dilation, hardness of the nuclei, but also, and to a greater extent, on zonular weakness, which is why we can find pseudoexfoliative patients for whom surgery is very straightforward and others for whom it is extremely difficult, especially with very hard cataracts, significant zonular weakness and poor pupillary dilation (Figure 2). UPDATE/ EVIEW 1Department of Ophthalmology, Complejo Hospitalario Universitario Orense, Orense, Spain 2Department of Ophthalmology, Complejo Hospitalario Universitario A Coruña, A Coruña, Spain 3Centro de Oftalmología Barraquer, Barcelona, Spain Financial Disclosure: The authors do not have any financial interest in any of the products mentioned Corresponding Author: Dr Ramón Lorente Moore C/ Calle del Paseo, 19-2o, 32003, Orense, Spain, E-mail: [email protected]