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Hyaluronic acid and cataract
The Tanabata has already passed, is it still immersed in the sweetness of your loved ones? But have you ever thought that one day, even the face of a loved one will be difficult to see, the whole world is shrouded in a fog, and the main culprit of these troubles is it - cataract
Causes of cataract
The lens of the human eye consists primarily of water and protein, and the organic combination of proteins allows light to pass through and focus on the retina. All kinds of reasons such as aging, genetics, local dystrophies, immune and metabolic abnormalities, trauma, poisoning, radiation, etc., can cause metabolic disorders of the lens, causing lens protein denaturation and turbidity, leading to cataracts.
Incidence of cataract
Cataracts can cause progressive vision loss. Due to the opacity of the crystal cortex, the refractive power of different parts of the lens can be different, and there may be glare, single eye double vision, and increased myopia. In 2016, the proportion of China's aging population (>65 years old) reached 10.8%. It is estimated that China's population over 60 years old will exceed 400 million in 2050. The elderly are a frequent population of cataracts. In the elderly between the ages of 60 and 89, the incidence of cataracts is 80%, and the incidence rate of people over 90 years old is over 90%.
Cataract mainly relies on surgery and medication. Surgical treatment includes extracapsular cataract extraction and phacoemulsification. Phacoemulsification is a new type of cataract surgery performed at home and abroad in recent years. Ultrasound is used to pulverize the lens nucleus to form a chyle-like shape, and then aspirate together with the cortex. After the lens is retained, the lens can be implanted at the same time, and the intraocular lens can be implanted at the same time. The main steps can be summarized as dyeing, capsulorhexis, nucleus fragmentation and aspiration, sebum aspiration, and intraocular lens implantation. There are three times when the ophthalmic viscoelastic agent needs to be injected in the whole process. The first time is before the capsulorhexis, which plays a supporting role, providing operation space for the capsulorhexis in the anterior chamber; the second time is to protect the cornea before the nucleus is broken. The cells are protected from ultrasound; the third time is the buffering effect before the implantation of the intraocular lens to avoid the impact on the cornea and the posterior capsule when the crystal is implanted.
Classification of viscoelastics
Viscoelastics are classified into cohesive and diffuse types. The cohesive molecular weight and high viscosity have good support and shock absorption, but the coating property is poor and cannot be well distributed on the surface of the tissue. The diffused molecular weight and low viscosity can adhere well to the surface of the tissue, but the supporting effect is poor, which does not provide sufficient surgical operation space. In phacoemulsification, the first and third injections were cohesive viscoelastic agents, and the second injection was a diffuse viscoelastic.
Clinical use of medical sodium hyaluronate gel
As a viscoelastic agent, sodium hyaluronate gel has the characteristics of viscosity, pseudoplasticity, viscoelasticity, viscoplasticity and coating property. It is a non-toxic and non-antigenic macromolecular liquid substance injected into the tissue cavity. It can play the role of filling, protecting and lubricating, thus improving the quality of surgery and the safety of surgical treatment, which brings convenience to the doctor and brings benefits to the patient.
200 cases of cataract in the clinical trial (200 eyes). There were 114 males (114 eyes) and 86 females (86 eyes). The age ranged from 52 to 78 years old, with an average age of 66 years. All cases were free of diabetes and no complications such as glaucoma or uveitis, no history of ocular trauma or history of surgery. 100 eyes were in the 2% methylcellulose group and 100 eyes were in the medical sodium hyaluronate group. Preoperative anesthesia, injecting a viscoelastic agent into the anterior chamber, performing a central continuous circular capsulorhexis, and then aspirating the crystal and cortex with a sovereign white star phacoemulsifier, then injecting a viscoelastic agent into the anterior chamber and the capsular bag, implanting the crystal and injecting it. The miotic agent is then aspirate and remove the viscoelastic and miotic agents. After the injection of anti-inflammatory injection, the surgery is over.
The incidence of intraocular pressure increase and intraocular pressure increase after methylcellulose treatment were significantly higher than those of intraoperative sodium hyaluronate. The difference was significant. The intraocular pressure increased on the day after phacoemulsification, and the total incidence was 35.56%. Therefore, it is necessary to attach great importance to the observation of early intraocular pressure after cataract surgery. High-risk groups with elevated intraocular pressure: complicated cataracts, optic disc damage, or patients with retinal and optic neuropathy should use high-quality viscoelastic agents during surgery.
Yishu Kang Medical Sodium Hyaluronate Gel produced by Changzhou Pharmaceutical Research Institute Co., Ltd. has good biocompatibility and can be absorbed and metabolized by the human body. It has higher molecular weight and higher viscoelasticity than similar products. And better physical shear. In the course of use, after routine dilation and anesthesia, the rectus muscle traction line is placed, the conjunctival flap based on the ankle is made, and the auxiliary incision is made by puncture at the corneal margin at 2 o'clock, 2.5-3 mm behind the upper limbus. 5.5-6mm parallel to the incision of the limbus plate, the tunnel is separated into the transparent cornea, puncture into the anterior chamber, and can be injected.