Primary and secondary cataracts – how they differ

Primary cataracts are simply congenital cataracts, either as a result of complications or resulting from a clouding of the lens of the eye that occurs with age and is associated with aging and accompanying metabolic disorders. Cataract secondary is a complication of surgery to remove primary cataracts.

Primary cataract

Primary cataract is the progressive clouding of the lens until it becomes completely opaque.

It may appear as:

• Congenitalcataract (cataracta congenita) – diagnosed either at birth or developing in children during the first years of life.

• Complicatedcataract (cataracta complicata) – is diagnosed as a complication after other chronic eye diseases (e.g. glaucoma, retinal detachment, pigmentary retinopathy, inflammation, high myopia) or systemic diseases (e.g. diabetes, hypoparathyroidism). This group also includes drug-induced cataracts, arising from the adverse effects of certain drugs, such as steroids.

• Acquired/degenerativecataract (cataracta acquisita), commonly referred to as senilecataract– is a progressive clouding of the lens associated with aging and accompanying metabolic disorders.

Treatment of primary cataract

Primary cataracts cannot be treated pharmacologically – the patient must undergo surgery to replace his own opaque lens with an implantable artificial lens. The choices are:

• Cataract phacoemulsification – is a method of removing cataracts using an ultrasonic tip and implanting an artificial intraocular lens.
• Cataract femtoemulsification – is surgery with a high-precision femtosecond laser. It’s a method that involves making micro-incisions (called ports) in the cornea and removing the cloudy lens through them and then inserting a new one.

Secondary cataract

Secondary cataract is a complication after surgical removal of the patient’s own opaque lens, or primary cataract. In its course, the posterior lens capsule of the eye, which is not removed during surgery to remove the primary cataract, becomes opacified.

Secondary cataract, or Posterior Capsule Opacification (PCO), occurs as a result of posterior capsule epithelial cells proliferating and settling on the back of the lens, making it thicker and less translucent.

This complication can occur both several weeks and several years after surgery. Among its causes are indicated infections inside the eye that lead to damage to the capsule or PEX, or Pseudoexfoliation Syndrome, an eye disease characterized by the accumulation of material called pseudoexfoliation on various structures of the eye.

Secondary cataracts can also be induced by diseases such as diabetes, hypoparathyroidism or atopic dermatitis. It is also blamed on a developing visual defect, especially myopia or congenital retinal defects.

The symptoms of secondary cataracts are similar to those of primary cataracts (including a blurring of the vision, a decrease in contrast, and impaired color vision), so patients are often horrified that the condition they were promised to get rid of once and for all is back!

Note, however, that this time the opacity is not located in the lens itself – an artificial lens implanted in place of your own lens does not opacify! – but in the remnants of the own lens, i.e. in the posterior capsule, which is left to support the new lens in its proper place.

How is secondary cataract treated?

As with primary cataracts, secondary cataracts cannot be cured pharmacologically or corrected with glasses or contact lenses. A posterior capsulotomy procedure is required.

The procedure involves making a small hole in the posterior lens capsule and allows for an immediate improvement in vision. It is performed under local anesthesia. During the procedure, the patient sits in front of a slit lamp, with which a YAG laser is integrated. It sends out two beams, which are transmitted to a control device located in the slit lamp.

The cooperation of the two devices makes it possible to precisely “shoot” the laser beams (laser impact) and make a hole in the desired location. Sometimes several, and sometimes a dozen or dozens of such “shots” are needed, but the procedure is short anyway – it takes from a few to several minutes. It is painless, but the pupil-dilating drops used prior to the procedure cause vision impairment and photophobia to persist for up to several hours after the procedure.

Can secondary cataracts reappear? Very rarely, but it can.