Cataracts rank first among the blindness-causing eye diseases in the world and are also the first blindness-causing eye disease in China. With the gradual aging of our society, the number of cataract patients will increase. Currently, the only effective cataract treatment is surgery. Cataract surgery has made rapid development in the past half century and has gone through three stages: intracapsular cataract extraction, extracapsular cataract extraction and ultrasound emulsion extraction. In the past, cataract surgery required a large incision (about 12mm), large astigmatism in patients after surgery, long recovery time and unsatisfactory results. The mainstream of modern cataract surgery is ultrasonic emulsification combined with IOL implantation, which is very popular among patients and doctors because of the small surgical incision (about 3.2mm), fast recovery and no obvious pain during the operation.
With the progress of the times, microincision cataract surgery was born to meet the higher requirements of patients. Micro-incision cataract surgery refers to surgery with incisions below the standard cataract surgery incision. At present, the clinical incision can be 1.8mm, which is only the size of a pinhole of an embroidery needle. Compared with standard incision cataract surgery, micro-incision cataract surgery has become the trend of cataract surgery in clinical practice with its advantages such as small surgical source astigmatism, fast recovery, low incidence of incision leakage and short learning curve.
1. Microincision ultrasound phacoemulsification generally refers to cataract surgery where the incision is reduced to less than 2.0mm. It mainly contains two obvious features: firstly, it adopts a new and more efficient energy release mode, which can effectively reduce the ultrasound energy during the surgery and reduce the heat, and minimize the damage to the eye tissue caused by the surgery; secondly, the incision is reduced, so the anterior chamber becomes more dense and stable, the postoperative corneal astigmatism becomes smaller, and the chance of intraocular infection is lower.
Coaxial microincision ultrasonic cataract surgery is done through a 1.8mm clear corneal incision. It has been found that patients with coaxial microincision ultrasonic cataract surgery recover their vision faster than standard ultrasonic cataract surgery after surgery, mainly due to the reduced incision, reduced surgical source astigmatism, and earlier stabilization of astigmatism status. For coaxial microincision surgery, the smaller diameter surgical instruments match the reduced incision, and under the protection of the perfusion cannula, the microincision surgery fully demonstrates the advantages of good incision closure and rapid recovery. While coaxial microincision ultrasound emulsification adopts specially designed ultrasound emulsification needle and cuff, which can ensure sufficient perfusion while reducing the incision, so that the inflow volume is much larger than the outflow volume, and with the anterior chamber stable fluid flow system, perfect anterior chamber stability can be achieved during the surgery. For coaxial microincision surgery, the smaller diameter surgical instruments match the reduced incision, and under the protection of the perfusion sleeve, the microincision surgery fully shows the advantages of good incision closure and rapid recovery.
2. Analysis of postoperative visual quality:The visual quality after cataract surgery mainly depends on the corneal astigmatism caused by the surgery, and microincisional ultrasound emulsification can obtain better visual quality because of its smaller incision and theoretically lower value of corneal astigmatism caused. According to Tsuneoka et al, 3.0
mm clear corneal incision was more than 1 times greater than 1.8 mm incision in postoperative corneal astigmatism. Micro-incision ultrasound emulsification also significantly reduced surgical-derived astigmatism compared with conventional small-incision ultrasound emulsification, and the best-corrected visual acuity on postoperative day 1 was significantly better than that of the small-incision group. The postoperative corneal astigmatism caused by coaxial microincision ultrasound emulsification were all smaller, with no significant difference, and the postoperative visual acuity levels were roughly similar.
3. Development trend of microincision cataract surgery: In the current surgical equipment and evaluation system, coaxial microincision cataract surgery is a more ideal surgical approach to balance the advantages and disadvantages of standard coaxial incision and two-handed microincision ultrasonic cataract surgery. Although microincision cataract surgery still has certain shortcomings and deficiencies, reducing the surgical incision has always been the trend and the primary goal of cataract surgery development. With the continuous improvement and refinement of ultrasound emulsification equipment, optimization of ultrasound needle design, ultrasound mode, fluid flow settings and the development of IOLs. Microincision cataract surgery can overcome the disadvantages while maintaining its advantages, achieve safe and efficient surgery while ensuring the integrity and stability of the incision, and achieve the goal of cataract refractive surgery while minimizing the surgical incision and reducing tissue damage.
Based on the above analysis, we believe that microincisional ultrasound phacoemulsification will become a new trend in the history of cataract surgery due to its unique advantages, and is expected to become the mainstream procedure for cataract surgery in the future.