Cataract is one of the major causes of blindness in the elderly. With the increasing improvement of cataract extracapsular extraction combined with IOL implantation, the quality of life of cataract patients after surgery has reached a great improvement. However, there are still some cataract surgery patients who cannot implant IOLs in phase I due to severe posterior capsule damage or loss of posterior capsule due to various intraoperative reasons, and the limitations of the surgical conditions at that time, resulting in a decrease in the quality of visual life. For this group of patients, a second-stage IOL implantation is required. 1. Data and Methods 1.1 Clinical Data
This group of 33 cases and 33 eyes from rural patients, 8 male and 25 female cases, aged 56 to 84 years old, average 68 years old. There were 18 cases of postoperative cases in external hospitals and 15 cases in our hospital. There were 3 cases after having received glaucoma surgery and 2 cases after traumatic cataract surgery. The preoperative best corrected visual acuity was 0.15 in 1 eye, 0.2~0.4 in 9 eyes, and ≥0.5 in 23 eyes. The operation was performed 3 months to 16 years after the original cataract surgery, with an average of 1.3 years. 31 eyes had round pupils, 2 eyes had pear-shaped pupils with significant upward shift, but were suitable for second-stage implantation of anterior chamber-type IOLs. Preoperative routine ocular and systemic examination, 0.25% chloramphenicol eye drops were ordered for 3 days, and 20% mannitol injection 250 ml was rapidly administered intravenously 2 hours before surgery. 1.2 Surgical methods
All surgeries were performed under an operating microscope. Preoperative 1% pilocarpine eye drops were spotted 3 times to achieve pupil narrowing. The eye was disinfected and the head was wrapped with a towel. 2% lidocaine injection and 0.75% bupivacaine injection were mixed in equal amounts of 4.5mml for two-way peribulbar anesthesia and subconjunctival local infiltration anesthesia, the bulbar conjunctiva was cut, and a scleral tunnel incision of about 6.5mm in length was made 1~1.5mm behind the temporal corneoscleral rim to reach the anterior chamber 1mm inside the clear cornea, and a small amount of viscoelastic was injected first and then along the iris A small amount of viscoelastic is injected first, then along the periphery of the iris ring; the amount injected is sufficient to maintain a certain anterior chamber depth. The anterior chamber IOL is implanted with lens forceps by enlarging the internal incision, making the anterior climb reach the contralateral atrial angle first, and then sending the posterior climb directly into the atrial angle below the inner corneal flap at the incision, making appropriate adjustments to the position of the lens climb in order to balance the forces of each climb. An incision of approximately 2.mm was made with an anterior chamber puncture knife in the middle of the two points of force of the posterior climb at the inner corneal limbus of the incision, and a peripheral iridotomy was made, which was not done for the existing peripheral iridotomy. The scleral tunnel incision was intermittently sutured and the viscoelastic behind the lens and in the anterior chamber was aspirated with a manual aspiration needle, taking care to maintain anterior chamber stability. The conjunctival flap was fixed by para-cautery and subconjunctival injection of 20,000 units of gentamicin injection and dexamethasone 3mg. 2. RESULTS 2.1 Postoperative visual acuity
Follow-up 3 months~2 years, average 10 months, postoperative last best corrected visual acuity 0.1 in 1 eye, accounting for 3.03%; 0.2~0.4 in 6 eyes, accounting for 18.18%; ≥0.5 in 26 eyes, accounting for 78.79%, preoperative best corrected visual acuity ≥0.5 in 23 eyes, accounting for 69.70%, compared with preoperative postoperative (χ2=0.32), not statistically significant (P>0.5) . 2.2 Intraoperative complications One eye with iris prolapse was given effective intraoperative return, two eyes with vitreous overflow, and one eye with bleeding during iris circumcision. 2.3 Postoperative complications
All patients were routinely treated with anti-inflammatory drugs after surgery, and the medication was changed on the first postoperative day, and there was almost no inflammatory reaction in the anterior chamber of 1 eye, while the remaining eyes had different degrees of inflammatory reactions, among which, 2 eyes with significant inflammation in the anterior chamber were controlled by giving local and systemic application of anti-inflammatory drugs; 8 eyes had mild corneal edema in the early stage, and 7 eyes had corneal inner fold lines, which disappeared after symptomatic and anti-inflammatory treatment; 4 eyes with transient IOP elevation, slit There was no pupillary blockage by slit lamp observation, and the iris peripheral incision was open and not blocked. 20% mannitol injection 250ml was given as a rapid intravenous drip, and vinpocetine tablets were given orally, and normal IOP was restored within 3 days; 3 eyes had a little blood accumulation in the anterior chamber, and the blood accumulation disappeared after hemostatic treatment and subsequent blood circulation treatment. 2.4 Anterior chamber IOL location and distant complications
There were 29 eyes in the 3 o’clock to 9 o’clock position and 4 eyes in the 4 o’clock to 10 o’clock position. The distant complications were lens optical zone side clamping in 1 eye, recurrent iridocyclitis in 1 eye, and no corneal endothelial loss. 3. Discussion 3.1 Selection of the artificial lens
For patients with post-cataract surgery without lens, the choice of second-stage implanted IOLs are anterior chamber IOLs and posterior chamber IOLs, and implantation of posterior chamber IOLs has the obvious advantages of good surgical results, few complications, and low incidence of IOL tremor and dislocation; implantation of anterior chamber IOLs has a higher incidence of late occurrence of large vesicular keratopathy than posterior chamber IOLs High In patients with severe posterior capsule loss or intracapsular removal of the lens, implantation of a posterior chamber type requires ciliary suture fixation of the IOL, which is difficult, damaging to intraocular tissues, and costly. All 33 eyes in this group had severe posterior capsule breakage or no posterior capsule, and the patients were from rural areas with poor economic conditions and aged 56-84 years, so anterior chamber IOL implantation was chosen. 26 eyes (78.79%) had postoperative visual acuity ≥0.5, and 6 eyes (18.18%) had visual acuity 0.2-0.4, such that the patients’ basic needs of life were met. 3.2 Position of the anterior chamber IOL
The ideal location should be on the scleral eminence at the 3:00 to 9:00 position. This is because the scleral eminence is a relatively inanimate collagen tissue and the horizontal position of 3 to 9 o’clock avoids the location of the damaged upper corneal rim incision and the lower anterior chamber angle where inflammatory uveal response material is deposited downward due to gravity. We believe that after implantation of the anterior climb, the posterior climb can be placed directly into the anterior chamber angle below the incision, and generally only minor adjustments should be made so that the force on the four points of the two climbs is basically uniform. This position, or do other parts of the perirhinal resection, so that an additional incision is made. In this group, 29 eyes (87.88%) were in the 3 to 9 o’clock position. At follow-up, partial entrapment of the optical area of the IOL occurred in 1 eye. There was no corneal endothelial loss of compensation in all eyes. 3.3 Selection of surgical incision location
Because all of these patients had a history of cataract or combined surgical procedures such as glaucoma, the location of the surgical incision for the second-stage IOL implantation was mostly chosen to be temporal [7] to avoid scarring at the original surgical incision, but of course a clear corneal incision, as well as the original scleral tunnel incision shortly after cataract surgery, could also be chosen. The advantages of choosing the temporal scleral tunnel incision are the reduction of postoperative astigmatism, ease of operator manipulation, and avoidance of scarring at the original incision. In conclusion, for patients with severe posterior capsule breakage or loss of the posterior capsule due to various reasons, as well as for patients who are unable to implant an IOL in one stage due to surgical conditions at that time and become lens-less eyes, anterior chamber IOL implantation is still a better option in order to improve the quality of visual life, especially for the majority of elderly patients in rural areas.