What causes unstable zonules and how does this impact cataract surgery? is this common?

Eye surgeon can help: Hard to describe but... zonulopathy (disorders of zonules) can be "segmental," which is most commonly traumatic or iatrogenic; or "diffuse" as seen in eyes with pseudoexfoliation syndrome, retinitis pigmentosa, retinopathy of prematurity, advanced age, extreme myopia, Marfan syndrome, homocystinuria, Ehlers-Danlos syndrome, etc... More info at: https://www.eyeworld.org/be-prepared-loose-zonules