Observation on the Application of Hydroxypropyl Methyl Cellulose in Phacoemulsification of Cataract

Abstract: Objective: To observe the application effect of hydroxypropyl methylcellulose on corneal endothelial protection in cataract phacoemulsification. Methods: A retrospective analysis was performed on 1262 cases of phacoemulsification and intraocular lens implantation in our hospital from April 2013 to February 2015. All patients were randomly divided into two groups. Only sodium hyaluronate was used in the first group of 631 patients, and sodium hyaluronate and hydroxypropyl methylcellulose were used in the second group. Results: In the first group, the incidences of corneal edema on the first day, three days, one week, one month and three months after operation were 76 cases (12%), 50 cases (8%), 13 cases (2%), 2 cases (0.32%), 1 case (0.16%), the incidence of corneal edema on the first day, three days, one week, one month, and three months in the second group were 25 cases (4%), 6 cases (1%), 4 cases (0.63%), 0 cases (0%), 0 cases (0%). Conclusion: The application of hydroxypropyl methylcellulose in cataract phacoemulsification can effectively protect the corneal endothelium and reduce the occurrence of corneal edema.

Key words: cataract; phacoemulsification; hydroxypropyl methylcellulose; corneal edema

Soft shell technology was first reported by Arshinoff in 1999, and its purpose is to give full play to the performance advantages of cohesive and dispersive viscoelastics through combined application. The static viscosity and surface tension of the dispersible viscoelastic agent are both low, and can be evenly dispersed and distributed on the corneal endothelium to form a stable protective layer, which can effectively protect the cornea from damage to the corneal endothelial cells caused by various factors in phacoemulsification cataract surgery. , to reduce the occurrence of corneal edema after phacoemulsification.

1. Materials and methods

1.1 General Information

A retrospective analysis was performed on 1262 cases of cataract phacoemulsification and intraocular lens implantation performed in our hospital from April 2013 to February 2015. All patients underwent preoperative corneal endothelial cell counts, and the cell counts were between 1200 and 3200. All patients were randomly divided into two groups. The first group consisted of 294 males and 274 females, 505 monocular and 63 binocular, the oldest was 90 years old, the youngest was 36 years old, and the average age was 57.6 years old. There were 20 cases of glaucoma and uveitis complicated with cataract, 16 cases of traumatic cataract, 214 cases of senile cataract with grade 1 to 2 nuclei, and 381 cases with grade 3 to 4 nucleus; the second group included 282 males and 286 females, the oldest 91 years old, the youngest is 39 years old, and the average age is 58.3 years old. There were 18 cases of glaucoma and uveitis complicated with cataract, 20 cases of traumatic cataract, 210 cases of senile cataract with grade 1-2 nucleus, and 383 cases with grade 3-4 nucleus. There was no significant difference in the general data of the two groups of patients (P>0.05), and they were comparable.

1.2 Surgical method

(1) Operation method: after topical anesthesia with Benoxi (Japan Santen Pharmaceutical) before operation, the conjunctival sac was flushed with 0.5% iodophor; a side incision was made on the corneal limbus, viscoelastic was injected, a transparent corneal incision was made above, and the circular capsulorhexis was performed to the The diameter is 5-6 mm; then the water separation is carried out, the phacoemulsification of the lens is carried out, the cortex is aspirated by I/A until it is completely clean, and then an appropriate amount of viscoelastic agent is injected, and a foldable intraocular lens is implanted; finally, the residual viscoelastic agent is completely sucked out, and the water-tight The main incision and side incision were made, and the conjunctival sac was bandaged with tobramycin and dexamethasone eye ointment, and the operation was completed. (2) Selection of viscoelastic agent: In the first group, sodium hyaluronate was injected into the anterior chamber during operation; in the second group, hydroxypropyl methylcellulose was injected into the anterior chamber during operation, followed by sodium hyaluronate, and Push the hydroxypropyl methylcellulose into the intraocular lens injector when the crystal is used. (3) Ultrasound in the capsular bag was used for phacoemulsification. All operations were performed by the same doctor. There were no complications such as rupture of the posterior lens capsule and corneal endothelial avulsion during the operation. Other surgical steps and surgical consumables were the same.

1.3 Postoperative treatment

All patients took tobramycin dexamethasone eye drops and diclofenac sodium eye drops after the operation, with an interval of 10 minutes between the two eye drops, one to two drops each time, four times a day, and changed to one day after one week Three times, in descending order, a total of around the eyes. Recombinant bovine basic fibroblast growth factor ophthalmic gel drops, once a night, for two weeks.

2. Results

In the first group, the incidences of corneal edema on the first day, three days, one week, one month, and three months after operation were 76 cases (12%), 50 cases (8%), 13 cases (2%), and 2 cases (0.32%), 1 case (0.16%), the incidences of corneal edema in the second group were 25 cases (4%), 6 cases (1 %), 4 cases (0.63%), 0 cases (0%), 0 cases (0%). The chi-square test showed that the incidence of corneal edema in the second group was significantly lower than that in the first group, P<0.05, the difference was statistically significant.

3 Discussion

Corneal endothelial cells are the physiological barrier for the cornea to maintain its normal function. Once damaged, it will cause different degrees of corneal decompensation, edema and bullous keratitis. Corneal edema after intraocular lens surgery is often caused by corneal endothelial injury. When the number of corneal endothelial cells is less than 1000/mm², corneal decompensation will occur and edema will occur.

The basic working principle of all phacoemulsification handles is that the probe vibrates linearly along the longitudinal direction at a very high speed, the vibration frequency is from 27000 to 80000 times per second, and the amplitude is about 1/7620cm. Microparticles (emulsions), these emulsified small particles are drawn out through the wick of the probe. During the operation, the energy of emulsification can be adjusted according to the hardness of the crystal nucleus. The greater the energy, the easier it is to cause damage to the corneal endothelium.

Ophthalmic hydroxypropyl methylcellulose is a polysaccharide molecular compound. Its molecules are stable and will not be hydrolyzed by any enzymes, so it has no physiological activity and will not be metabolized in the body; it is non-toxic and harmless and does not cause inflammation; physical and chemical properties Stable and easily diluted, rinsed and aspirated. Residues in the front will not cause persistent high intraocular pressure. Combining it with sodium hyaluronate can maximize the advantages of different viscoelastic agents and play an auxiliary and protective role in phacoemulsification cataract surgery. The combination of the two occupies the space adjacent to the anterior chamber and capsular bag, and Divide the anterior chamber into two, one part forms a protective immobile space, while the other part acts as a variable space during operation. Maximize the protective effect on the corneal endothelium.

At the same time, due to the poor pseudoplasticity of hydroxypropyl methylcellulose, which is mainly viscous, an appropriate amount of hydroxypropyl methylcellulose can be pushed into the crystal injector to replace sodium hyaluronate during the crystal implantation process, not only It can significantly reduce the resistance during bolus injection, and can effectively reduce the dosage of sodium hyaluronate, thereby reducing the operation cost.