Complications after cataract surgery

Intraoperative complications after cataract surgery are as follows:

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Posterior capsule rupture

This is a fairly serious complication, as it may be accompanied by loss of the vitreous body, posterior migration of the lens masses, and, less commonly, expulsive hemorrhage. If not treated appropriately, long-term consequences of vitreous loss include an upwardly pulled pupil, uveitis, vitreous opacities, wick syndrome, secondary glaucoma, posterior dislocation of the artificial lens, retinal detachment, and chronic cystic macular edema.

Signs of posterior capsule rupture

• Sudden deepening of the anterior chamber and instantaneous dilation of the pupil.
• Failure of the core, inability to pull it to the tip of the probe.
• Potential for vitreous aspiration.
• The ruptured capsule or vitreous body is clearly visible.

The tactics depend on the stage of the operation at which the rupture occurred, its size and the presence or absence of vitreous prolapse. The basic rules include:

• introduction of viscoelastic behind the nuclear masses in order to remove them into the anterior chamber and prevent vitreous hernia;
• insertion of a special gland behind the lens masses to close the defect in the capsule;
• removal of lens fragments by introducing viscoelastic or removing them using phaco;
• complete removal of the vitreous body from the anterior chamber and the incision area with a vitreotome;
• The decision to implant an artificial lens should be made taking into account the following criteria:

If large amounts of lens material have entered the vitreous cavity, an artificial lens should not be implanted, as it may interfere with fundus visualization and successful pars plana vitrectomy. Implantation of an artificial lens may be combined with vitrectomy.

In case of a small rupture of the posterior capsule, careful implantation of the ZK-IOL into the capsular bag is possible.

In case of a large rupture and especially with an intact anterior capsulorhexis, it is possible to fix the ZK-IOL in the ciliary sulcus with placement of the optical part in the capsular bag.

Insufficient capsule support may necessitate suturing of an intraocular lens in the sulcus or implantation of a PC IOL with a glide. However, PC IOLs are associated with more complications, including bullous keratopathy, hyphema, iris folds, and pupillary irregularities.

Dislocation of lens fragments

Dislocation of lens fragments into the vitreous after rupture of the zonular fibers or posterior capsule is rare but dangerous, as it can lead to glaucoma, chronic uveitis, retinal detachment, and chronic macular edema. These complications are more often associated with phaco than with EEC. Uveitis and glaucoma should be treated first, and the patient should be referred to a vitreoretinal surgeon for vitrectomy and removal of lens fragments.

NB: There may be cases when it is impossible to achieve the correct position even for a PC-IOL. In such cases, it is safer to refuse implantation and decide on the correction of aphakia using a contact lens or secondary implantation of an intraocular lens at a later date.

The timing of the operation is controversial. Some suggest removing the remnants within 1 week, since later removal affects the restoration of visual functions. Others recommend postponing the operation for 2-3 weeks and conducting a course of treatment for uveitis and increased intraocular pressure. Hydration and softening of the lens masses during treatment facilitates their removal using a vitreotome.

The surgical technique involves pars plana vitrectomy and removal of soft fragments with a vitreotome. Denser nuclear fragments are connected by injection of viscous fluids (e.g., perfluorocarbon) and subsequent emulsification with a fragmatome in the center of the vitreous cavity or removal through a corneal incision or scleral pocket. An alternative method for removing dense nuclear masses is their crushing followed by aspiration,

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Dislocation of the ZK-IOL into the vitreous cavity

Dislocation of the ZK-IOL into the vitreous cavity is a rare and complex phenomenon, indicating incorrect implantation. Leaving the intraocular lens can lead to vitreous hemorrhage, retinal detachment, uveitis, and chronic cystoid macular edema. Treatment is vitrectomy with removal, reposition, or replacement of the intraocular lens.

With adequate capsular support, repositioning of the same intraocular lens into the ciliary sulcus is possible. With inadequate capsular support, the following options are possible: removal of the intraocular lens and aphakia, removal of the intraocular lens and its replacement with a PC-IOL, scleral fixation of the same intraocular lens with a non-absorbable suture, implantation of an iris-clip lens.

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Hemorrhage into the suprachoroidal space

Hemorrhage into the suprachoroidal space may result from expulsive bleeding, sometimes accompanied by prolapse of the contents of the globe. This is a serious but rare complication, unlikely to occur with phacoemulsification. The source of the hemorrhage is rupture of the long or posterior short ciliary arteries. Contributing factors include old age, glaucoma, enlargement of the anterior-posterior segment, cardiovascular disease, and vitreous loss, although the exact cause is unknown.

Signs of suprachoroidal hemorrhage

• Increasing shrinkage of the anterior chamber, increased intraocular pressure, prolapse of the iris.
• Leakage of the vitreous body, disappearance of the reflex and the appearance of a dark tubercle in the pupil area.
• In severe cases, the entire contents of the eyeball may leak out through the incision area.

Immediate action includes closing the incision. Posterior sclerotomy, although recommended, may increase bleeding and lead to loss of the eye. After surgery, the patient is given topical and systemic steroids to control intraocular inflammation.

Follow-up tactics

• Ultrasound examination is used to assess the severity of the changes that have occurred;
• The operation is indicated 7-14 days after the liquefaction of blood clots. The blood is drained, vitrectomy with air/fluid replacement is performed. Despite the unfavorable prognosis for vision, in some cases, it is possible to preserve residual vision.

Edema

Edema is usually reversible and is most often caused by the surgery itself and trauma to the endothelium from contact with instruments and the intraocular lens. Patients with Fuchs endothelial dystrophy are at increased risk. Other causes of edema include the use of excessive power during phacoemulsification, complicated or prolonged surgery, and postoperative hypertension.

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Prolapse of the iris

Iris prolapse is a rare complication in small incision surgeries but may occur in EEC.

Causes of iris loss

• The incision during phacoemulsification is closer to the periphery.
• Moisture seepage through the cut.
• Poor suture placement after EEC.
• Patient related factors (cough or other stress).

Symptoms of iris prolapse

• On the surface of the eyeball, in the area of the incision, fallen iris tissue is identified.
• The anterior chamber in the incision area may be shallow.

Complications: uneven wound healing, severe astigmatism, epithelial ingrowth, chronic anterior uveitis, macular edema and endophthalmitis.

Treatment depends on the interval between surgery and detection of prolapse. If the iris prolapses within the first 2 days and there is no infection, its reposition with repeated suturing is indicated. If the prolapse occurred a long time ago, excision of the prolapsed iris is performed due to the high risk of infection.

Intraocular lens displacement

Displacement of the intraocular lens is rare, but may be accompanied by both optical defects and structural disorders of the eye. When the edge of the intraocular lens is displaced into the pupil area, patients are bothered by visual aberrations, glare, and monocular diplopia.

Reasons

• Displacement of the intraocular lens occurs mainly during surgery. It can be caused by zonule dialysis, capsule rupture, and can also occur after conventional phacoemulsification, when one haptic part is placed in the capsular bag and the other in the ciliary sulcus.
• Postoperative causes include trauma, irritation of the eyeball and contraction of the capsule.

Miotic treatment is beneficial for minor displacement. Significant displacement of the intraocular lens may require its replacement.

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Rheumatogenous retinal detachment

Rheumatogenous retinal detachment, although rare after CE or phacoemulsification, may be associated with the following risk factors.

Before surgery

• Lattice degeneration or retinal breaks require pretreatment before cataract extraction or laser capsulotomy if ophthalmoscopy is possible (or as soon as it becomes possible).
• High myopia.

During the operation

• Loss of the vitreous body, especially if the subsequent tactics were incorrect, and the risk of detachment is about 7%. In the presence of myopia >6 D, the risk increases to 1.5%.

After surgery

• Performing YAG laser capsulotomy in the early stages (within a year after surgery).

Cystoid retinal edema

Most often it develops after a complicated operation, which was accompanied by a rupture of the posterior capsule and prolapse, and sometimes strangulation of the vitreous body, although it can also be observed after a successful operation. Usually appears 2-6 months after the operation.

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