Artificial crystal

    Intraocular lens (iol) - a precise optical device inserted into the eye to replace the removed opacities, gu hanqing wan rongxin liu xin is a contributor to the review of the project.

    An artificial lens, or intraocular lens, is a precise optical device that is surgically implanted in the eye to replace the removed lens.

Foreign names:intraocular lens

concept

   The main components of human crystals are protein and water, which can be fogged or cloudy as a result of aging.

Eye damage, some diseases, and even some medication can cause crystal atomization. According to statistics, over 90% of cataract cases are also caused by the aging process that humans must go through. The lens of the eye becomes cloudy and the vision is affected.

The only truly effective treatment for cataracts is surgery, where the lens is removed and replaced with an artificial lens, an artificial lens.Intraocular lens implantation is the most effective method for treating cataracts, and thousands of cataract patients have obtained good vision through this safe and effective surgical method.An artificial lens, or intraocular lens, is a precise optical component that is surgically implanted in the eye to replace the removed lens.

form

      Generally, it is composed of a circular optical part and a peripheral support loop. The diameter of the optical part is usually around 5.5 ~ 6mm. The support loop is used to fix the artificial crystal, which can be two C or J type linear support loops.

classification 

        According to the placement position, it can be divided into anterior chamber fixed intraocular crystals, iris fixed intraocular crystals and posterior chamber fixed intraocular crystals. Usually the best placement of the intraocular lens is in the pouch of the natural lens, that is, the location of the posterior chamber fixed intraocular lens.

According to hardness, it can be divided into rigid and foldable artificial crystals. Rigid lenses cannot be folded and require an incision (about 6 mm) the size of the optical part of the crystal to be inserted into the eye. In order to adapt to the progress of surgery, the materials of artificial crystals are improved step by step. The foldable artificial crystals can be folded in half or even curled up. They can be implanted with tweezers or implanters.

The characteristics of

       The artificial crystals can be divided into rigid artificial crystals, folded artificial crystals, specially treated artificial crystals, multi-focus/adjustable artificial crystals and aspherical artificial crystals, which have different characteristics respectively. 

(1) rigid artificial crystals

The incision is about 5.6 ~ 6 mm. Such a wound sometimes needs stitches, so the suture will cause certain astigmatism. After the operation, the reaction will be larger in the short term and the recovery time will be longer. 

2) folding artificial crystals

      The incision is generally 2.8-3.2mm. The incision does not need stitching. The astigmatism is also relatively small. Prevention of the formation of post-dysplasia, especially for patients with diabetes. The materials of foldable crystals are mainly silicone, hydrogel and acrylic acid.

(3) specially treated artificial crystals

      For some patients with certain eye diseases, this type of intraocular lens may be required. For example, the intraocular lens treated with heparin may be less inflammatory after surgery. Artificial crystals containing collagen can improve the compatibility of the crystals with tissue.

4) multi-focus/adjustable lens

In order to overcome this defect, people have developed and applied multi-focus artificial crystals, which are mainly divided into two types:

A, multi-zone, multi-focus type, has two zones, three zones, four zones, five zones, etc. In other words, the artificial crystal is divided into the central zone, the surrounding ring zone, different parts with different refractive power, generally 2.5D difference, forming two focal points, one looking close and one looking far. The downside of these crystals is that their near and far vision is affected by pupil size and ambient light.

B, diffraction multifocal type. Based on the wave theory of Huygens light, 30 channels of deep 2 m were carved on the rear surface of the artificial crystal, overcoming the influence of the divisional multifocal crystal on pupil size change.

(5) aspherical intraocular lens

Reduce aberration, effectively improve imaging quality, significantly improve night vision, close to normal eyes, especially for elderly patients or drivers who have trouble moving at night.

(6) yellow artificial crystal

      Ultraviolet absorber is added to all intraocular crystals to block ultraviolet light, but ordinary artificial crystals cannot block blue light, yellow artificial crystals are designed to block blue light and reduce the light damage to yellow spots.

(7) implantable miniature telescopic intraocular lens

For cataract patients with macular degeneration, the image can be magnified 3 times, to provide patients with monocular magnification of central vision

Force to improve quality of life, such crystals are still under clinical observation.