Cataract

Cataract is a the clouding of the cristaline (the lens in the eye).

Almost 50% of Retinitis pigmentosa patients develop a form of cataract know as posterior subcapsular cataract (PSC). This affects central vision and could be a big problem for RP patients having a restricted field of view. For more information about cataracts in general, visit http://www.visionaware.org/info/your-eye-condition/cataracts/12

At this moment, surgery is the only way of "curing" cataract. A surgeon will replace the natural lens in the patient eye with an IOL (intra ocular lens) usualy made from acrylic or silicone.

There are many types of intra ocular lens, so make sure you read The RPer guide about choosing Intra Ocular Lens for cataract surgery

After surgery, many patients develop a complication called Posterior capsular opacification (PCO) that is usualy resolved with an YAG laser intervention. More on http://www.visionaware.org/info/your-eye-condition/cataracts/can-a-cataract-come-back/125. Some IOLs designs seems to be better then others preventing PCO (see rectangular edge design IOLs).

Other complications could be:

-  Anterior capsular contraction.

- Macular Edema or CME. Some drugs could be used to reduce the risk of CME a couple of days before surgery.

Here are some articles about cataract and Retinitis Pigmentosa patients:

- Long-term clinical results after cataract surgery with and without capsular tension ring in patients with retinitis pigmentosa: a retrospective study

http://bmjopen.bmj.com/content/3/4/e002616.full

http://www.healio.com/ophthalmology/cataract-surgery/news/print/ocular-surgery-news/%7B447b563b-7884-49a6-bb59-3d0fba52384a%7D/extra-care-must-be-taken-in-unusual-cataract-cases http://www.healio.com/ophthalmology/news/blogs/%7B574c1678-7f5e-428b-af26-2475fcf52926%7D/uday-devgan-md/extra-caution-needed-in-cataract-surgery-for-retinitis-pigmentosa-cases http://www.healio.com/ophthalmology/cataract-surgery/news/online/%7B51005505-9e13-4e12-853d-1c5518580445%7D/blog-extra-caution-needed-in-cataract-surgery-for-retinitis-pigmentosa-cases

Phacoemulsification vs femtosecond laser in cataract surgery:

http://www.eyeworld.org/article-why-not-femto

Cataract surgeons should be aware of the increased risk for decentration and malposition of PC IOLs in patients with RP. Satisfactory results can be achieved by fixation of the PC IOL or AC IOL implantation. http://www.saudiophthaljournal.com/article/S1319-4534(11)00110-X/abstract?cc=y=

17% of RP cataract patients develop macular edema, 85% need YAG intervention after cataract surgery to treat PCO http://iovs.arvojournals.org/article.aspx?articleid=2381034

Long term research that could have impact on cataract:

- treating cataract with eyedrops that could "disolve" or "melt" the cataract : http://medicalxpress.com/news/2015-11-eye-cataracts-newly-chemical.html#nRlv http://www.viewpointtherapeutics.com/news/