Ocular contusions are common in ocular trauma. Contusions can result in iris root dissection, and small dissections that are not in the lid fissure area can be treated conservatively because they do not affect the quality of vision. However, iris root detachment located in the lid fissure area or of greater extent requires iris root repositioning surgery. We performed iris root dissection repair under the microscope in 23 cases (23 eyes) from June 1998 to October 2010 using the nodal suture method and achieved better results, which are reported below.
1. Data and Methods
1.1 General information
There were 23 cases (23 eyes) in this group. There were 17 male cases and 6 female cases. The age ranged from 5 to 56 years old, with an average of 27 years old. The time to visit the clinic after injury was 3 hours~5 days. The causes of injury were boxing injury to 11 eyes, explosion injury (including firecracker injury) to 5 eyes, slingshot injury to 1 eye, toy gunshot injury to 1 eye, and other accidental injuries to 5 eyes. The preoperative visual acuity was 0.05~0.8, 5 cases had obvious monocular diplopia, and 7 cases had photophobia. The iris root dissection range was 30°~90° in 14 eyes and >90° in 9 eyes. The surgery was performed 7~18 days after the injury, and 20% mannitol injection was routinely administered intravenously 1~2 hours before surgery.
1.2 Other ocular complications
There were 21 eyes with anterior chamber hematoma, 2 eyes with small amount of vitreous overflow, 2 eyes with choroidal rupture, 3 eyes with vitreous hemorrhage, 16 eyes with retinal edema, 1 eye with macular hole, 3 eyes with limited corneal clouding, 2 eyes with orbital wall fracture and 1 eye with secondary glaucoma.
1.3 Surgical method
A two-way posthemispheric anesthesia with general anesthesia in children was used. Under the microscope, subconjunctival local anesthesia was added to the site of iris injury, a conjunctival flap with the fornix as the base was made, cautery was applied to stop the bleeding, the corneoscleral rim was cut in full layer 1 mm after the corneal gray-white junction line, the anterior chamber was stabbed first in the central part, a certain amount of viscoelastic was injected, and the disposable needle with iris pulling hook, or flat-jaw forceps, or homemade head end folded into an acute angle was used to hook the broken iris rim and pull it to the incision, and 10-0 The nylon thread is passed through the anterior lip of the corneoscleral margin incision, the detached edge of the iris root, and the posterior lip of the incision in turn, and the sutures are ligated.
At the same time, an additional suture may be placed on each side, depending on the situation. If the iris root detachment is extensive, the incision can be made in sections, sutured in sections, and an auxiliary corneal incision made on the opposite side of the procedure to aid in the injection and aspiration of instruments and viscoelastic. A small amount of vitreous spillage into the anterior chamber can be cut out. The iris is repositioned and the conjunctiva is sutured in place after aspiration of the viscoelastic. After surgery, subconjunctival injection of 20,000 U of gentamicin and 3 mg of dexamethasone is given.
1.4 Postoperative management
Systemic antibiotics, corticosteroids, 20% mannitol injection intravenous drip to lower intraocular pressure, topical compound tropicamide active dilated pupil, tobramycin dexamethasone drip eye, and symptomatic treatment were applied as appropriate. All patients were followed up for more than 6 months, and examinations included visual acuity, intraocular pressure, slit lamp, fundus, and anterior chamber angioscopy.
2. Results
2.1 Iris and pupil morphology
The results of the follow-up examination 3 weeks after surgery showed that the iris root disconnection was roughly anatomically reset in all eyes, and the diplopia symptoms disappeared. The pupil was relatively round in 5 eyes, nearly elliptical but less than 5 mm in diameter in 9 eyes, and larger than 5 mm in diameter in the others, or with irregular pupils.
2.2 Visual acuity and intraocular pressure
Postoperative corrected visual acuity was 0.08 in 1 eye, which had a combined choroidal rupture with traces of rupture passing through the central macula, 0.1~0.3 in 5 eyes, and 0.4~1.0 in 17 eyes. In one eye, the IOP was about 35 mmHg at 3 weeks after surgery, and the original iris root disconnection in this eye reached the range of 120°. Glaucoma trabecular surgery was given, and the postoperative IOP was stabilized within the normal range.
2.3 Anterior chamber angle condition
The condition of the atrial angle at the site of the iris root detachment was highly variable, with some gaps in the iris root, some anterior and some posterior attachment points, and some Schwalbe lines were not visible.
2.4 Lens and vitreous fundus conditions
Three eyes had mild clouding of the lens cortex, one case had significant vitreous clouding, and one case had no secondary retinal detachment in the macular allograft hole at 6-month follow-up.
3. Discussion
The reason why contusions lead to iris root detachment is that the connection between the iris root and the ciliary body is weak and extended more tensely, and when the anterior part of the eye is contused, the pressure of the atrial fluid backward causes the iris to sink backward, and because of the lack of lens support behind this area, the weak root is prone to detachment. The extent of disconnection can be large or small, or it can occur in segments.
The principle of management of iris injury is to preserve the iris tissue and its structures as early as possible. Therefore, the root of the iris should be repositioned early to restore pupil shape, eliminate diplopia, and improve visual function. In cases where the detachment occurs above the iris, due to the coverage of the eyelid or a small detachment, visual impairment does not occur and may not be treated. In cases where the iris root detachment is large, the detached iris tissue obscures the pupil and causes monocular diplopia, or if the injured eye is the patient’s only useful eye, repositioning surgery is required.
Because contusion-induced iris root detachment is often combined with corneal edema, anterior chamber hemorrhage, and iridocyclitis, it is difficult to operate in a hurry and has a large postoperative inflammatory response. The disconnected edge was reset to its anatomic position.
In our group, 23 cases underwent microscopic iris root dissection repair surgery 7 to 18 days after the injury, and the residual partial clot was removed first, and the surgery was relatively smooth with little postoperative inflammatory response. For the timing of surgery, Cai Yongshu believes that it is important to rest quietly for 2 to 3 weeks after the injury. Therefore, the timing of the resetting surgery should also be individualized.
There are several methods of repairing iris root disruptions, but they are ultimately divided into 2 categories, namely, incisional and closed repair methods. The closed repair method avoids iris inlay, reduces the risk of intraocular infection, has a mild postoperative inflammatory response, no medically induced astigmatism, and rapid recovery of vision. The disadvantages are that it is not easy to get the needle through the edge of the iris break, the sharp needle tip has the potential to damage the lens, and it does not remove the vitreous that spills into the anterior chamber.
We successfully performed the repair in 23 eyes using the incisional nodal suture method. The experience was.
(1) Subconjunctival injection of anesthetic with a trace of epinephrine hydrochloride and scleral surface cautery at the incision site can provide good hemostasis and give a clear surgical view of the external port;
(2) For smaller dissection, 1 incision is used, and the anterior chamber is first pierced in the middle of the incision and an appropriate amount of viscoelastic is injected to maintain the depth of the anterior chamber, protect the corneal endothelium, prevent vitreous overflow, protect the ciliary process and other tissues, as well as to stop bleeding and help remove the accumulated blood clots;
(3) Iris pulling hooks are used during surgery to hook the iris breakaway edge tissue, sometimes with flat-tipped forceps or homemade disposable syringe needles with the tip folded at an acute angle;
(4) For larger iris root dissections, the corneoscleral rim is cut in sections and sutured in segments, and an auxiliary puncture port is made on the opposite or lateral side of the incision, through which auxiliary instruments can enter, and from which viscoelastic can be injected to push the iris tissue into the incision, facilitating the pulling out of the iris and shortening the distance of instruments into the anterior chamber. The risk of producing medically significant astigmatism is theoretically avoided by splitting the incision and suturing. This procedure was performed in 8 eyes with a dissection >90°;
(5) If there is a small amount of vitreous spillage at the detachment, it can be excised better than the closed approach. (6) The iris starts from the anterior middle of the ciliary body, and the end volume of the iris is the last of many protrusions on the iris surface, which is next to the root of the iris and represents the posterior border of the anterior chamber angle, so theoretically the root of the iris is disconnected at this site. will inevitably cause secondary damage to the anterior chamber angle.
The postoperative anterior chamber angle microscopy showed that some of the iris roots in the restored area had gaps and attachment points were either anterior or posterior, and some of the Schwalbe lines were not visible. However, after all, the restoration of the general anatomic position of the iris improved the shape of the pupil, improved the quality of vision, and facilitated subsequent ocular examinations and internal eye surgery. Some authors have reported that in injured eyes with combined iris root dissection and cataract, the iris root dissection was taken and repositioned and cataract surgery was performed in a single procedure.
During the surgery, the iris root detachment was first repositioned, and then the annular tearing capsule was performed to emulsify and remove the cloudy lens and implant the IOL, which achieved better clinical results and avoided secondary cataract surgery.
In this group of 23 cases (23 eyes), after reset by nodal suture method and symptomatic treatment under the microscope, the pupil was nearly round, monocular diplopia disappeared, and the visual acuity was 0.1~0.3 in 5 eyes and 0.4~1.0 in 17 eyes, indicating that the reset surgery not only anatomically reset the iris tissue and obtained a more round pupil, but also improved visual acuity and visual quality. As for the postoperative visual acuity of 0.08 in one eye, it was due to the combination of choroidal rupture and traces passing through the central macular area.
The IOP in one eye was around 35 mmHg at 3 weeks after surgery in the follow-up, and the original iris root disconnection in this eye reached the range of 120°. The atrial angle destruction in this case was large, which affected the normal drainage of atrial fluid, and anti-glaucoma surgery was given, and the postoperative IOP was stable and the visual field was not defective. Therefore, postoperative review of ocular conditions should be paid attention to, and problems should be detected and treated accordingly in a timely manner.
In conclusion, flexible application of nodal sutures, microscopic iris root dissection and repositioning surgery, supplemented by intraoperative use of viscoelastic, and reasonable use of auxiliary instruments to pull out or hook out the iris and suture it, can better return the pupil shape, eliminate diplopia, and improve visual quality.