OBJECTIVE: To observe the effect and complications of laser treatment for posterior cataract. METHODS: Laser posterior capsulotomy was performed in 76 patients (89 eyes) with posterior-onset cataract, and postoperative follow-up was performed from 3 to 6 months to observe the changes in visual acuity and postoperative complications before and after treatment. Results: All 89 eyes had one-time penetration of the posterior capsule membrane, and the success rate of incision was 100%, and the visual enhancement rate was 97,8%. The postoperative complications mainly included anterior uveitis, transient high intraocular pressure and IOL damage.
Conclusion: Laser posterior capsulotomy is a safe and effective good method to treat posterior cataract.
With the acceleration of population aging in China, cataract has become one of the major blinding eye diseases at present, and cataract hyperemulsification + IOL implantation has been rapidly developed and promoted in recent years, but the ensuing posterior cataract is a common reason for patients to lose their vision again after cataract surgery, and it seriously affects the outcome of cataract surgery. The incidence is 7,7% to 41% in adults and almost 100% in children [1]. The use of laser posterior capsulotomy for posterior cataract is a safe, proven method. In our ophthalmology department, 76 patients (89 eyes) with posterior-onset cataract were treated with laser from March 2012 to March 2013, and good clinical results were achieved after follow-up observation.
1. Data and methods 1. 1 General data 76 cases (89 eyes) of posterior cataract were treated with laser in our ophthalmology department from March 2012 to March 2013, of which 32 cases (37 eyes) were male and 44 cases (52 eyes) were female; their ages ranged from 5 to 76 years old, with an average of 62, 5 years; the laser treatment time ranged from 3 months to 6 years after cataract hyperemulsification + IOL implantation. All were posterior chamber IOLs with visual acuity of 0,04 to 0,3 before laser treatment. there were 3 levels of posterior capsule cloudiness, level 1: mild posterior capsule cloudiness with fundus visibility; level 2: moderate posterior capsule cloudiness with fundus partial visibility; level 3: complete visual invisibility of fundus [2]. In this group of patients, 18 eyes (20, 2%) had grade 1 membrane, 46 eyes (51, 7%) had grade 2 membrane, and 25 eyes (28, 2%) had grade 3 membrane.
1, 2 Methods Before treatment, a detailed history was taken, and all patients were routinely examined for visual acuity, intraocular pressure, fundus, and the anterior segment of the eye under slit lamp, paying particular attention to the degree of clouding of the posterior capsule and the relationship with the position of the IOL. The pupil was dilated to about 6 mm by using a domestic laser with a wavelength of 1064 nm and a single pulse of 1,8 to 4,0 mJ. The pupil was dilated to about 6 mm by using topical compound tropicamide drops every 5 minutes for 4 times before surgery. After focusing the laser aiming light on the surface of the posterior capsule membrane, the laser is started to be emitted by moving backward slightly, starting from low energy and increasing gradually according to the thickness and denseness of the posterior capsule membrane until it can just penetrate the posterior capsule membrane. The laser energy should be adjusted according to the thickness of the posterior capsule at any time during the treatment. Depending on the cloudiness of the posterior capsule, the posterior capsule can be cut in a “+” or “Q-shaped” incision. The size of the posterior capsulorhexis was decided according to the position of the IOL and the position and size of the pupil, and the general aperture was 2-3 mm, with the maximum not exceeding 4 mm. 89 eyes were successfully incised at one time. The eyes were routinely given pelorophene drops 4-6 times a day after surgery, and the visual acuity, IOP and anterior segment of the eye were rechecked after 24 hours. Very few eyes with elevated IOP were given IOP-lowering drugs and followed up for 3-6 months after surgery.
The success rate of posterior capsulotomy was 100%, and the visual acuity of the patients improved significantly after laser surgery, with the best visual acuity reaching 0,9, visual acuity ≤0,3 in 18 eyes (20,2%) and visual acuity >0,3 in 71 eyes (79,8%). The children with congenital cataracts were considered to be related to their form deprivation amblyopia, and the visual acuity increase rate was 97,8%. There was a significant difference between the postoperative visual acuity after laser treatment and the preoperative visual acuity (p<0,05). All patients in this group had different degrees of anterior uveitis reaction after laser treatment, which disappeared within 1 week after surgery with the administration of topical praprofen drops; 7 eyes (7, 9%) had elevated intraocular pressure after surgery, all of which were below 35 mmHg and were relieved within 24 hours after treatment with IOP-lowering drugs; 6 eyes (6, 7%) had postoperative IOL damage, all of which were after IOL There were no IOL fractures and no visual acuity was affected. With the accelerated aging of our population, cataract has become one of the major blindness-causing eye diseases, and cataract hyperemulsification + IOL implantation has been rapidly developed and promoted in recent years, but the ensuing posterior cataract is a common reason for patients’ vision loss again after cataract surgery, and it seriously affects the results of cataract surgery. The main cause of posterior cataract formation is the proliferation of lens epithelial cells extending toward the posterior capsule membrane and fibrogenesis. Mechanical damage from surgical instruments during cataract surgery and postoperative residual lens cortical irritation and postoperative inflammatory response are also involved in the process of membranous posterior cataract formation [3]. When posterior cataract affects vision, surgical treatment or laser for posterior capsulotomy can be chosen, and the surgical risk is relatively small because the use of laser to cut the cloudy posterior capsulorhexis does not require incision of the eye. At present, laser posterior capsulotomy basically replaces surgical incision and is a safe and effective way to treat posterior cataract. Laser posterior capsulotomy mainly creates plasma in the target tissue through the ionization effect, and uses the shock wave generated by its blast to cause tissue destruction and lysis [4]. This surgical method is safe, simple, and less painful for the treatment of posterior cataract, with high surgical success rate and rapid postoperative visual recovery. However, laser posterior capsulotomy is still an internal eye surgery, and its main complications include elevated intraocular pressure, IOL damage, anterior uveitis, macular cystoid edema and retinal detachment. Posterior cataract will gradually increase the degree of mechanization of the posterior capsule over time, and the heavier the degree of mechanization, the greater the laser energy required and the more complications there will be. Therefore, it is also important to choose the timing of laser treatment for posterior cataract. Most scholars believe that the timing of laser treatment for posterior cataract should be chosen before the formation of grade 3 posterior cataract. Sun Youlan [5] believes that the best time for laser treatment of adult posterior cataract is 3-6 months after its formation because the posterior capsule membrane is most likely to be cleaved during this period, and the laser energy required for treatment is low and complications are few. In conclusion, laser treatment of posterior cataract is simple to operate, can effectively improve the visual acuity of the operated eye, has precise efficacy, few complications, and quick recovery of visual acuity after surgery, and is currently a safe and effective good method for treating posterior cataract.