Cataract surgery is considered to be one of the most complicated high-tech dependent surgeries. But you will be even more astonished when I tell you that cataract surgery is one of the oldest surgeries known to humanity, as it was practiced since the fifth century BC. in India and was called “Couching”. Being such an intricate procedure, are there complications? In this article we will try to highlight the most important cataract surgery complications, and the mitigation procedures used to eliminate or decrease their impact on patients.
In order to simplify the subject, we will categorize the complications after surgery for cataract surgery and IOL (Intraocular Lens) implantation into 2 groups: early complications that happen during the operation procedure, or early post-operative and late complications that happen days or months after surgery. The complications listed below are sorted according to the seriousness of the condition.
I. Most critical and early onset complications:
This is the most important and feared complication in cataract surgery. The complaint consists of: diminution of vision, severe pain that increases in intensity as time passes if left without treatment, redness of the eye, severe headache…etc. These symptoms develop within 2 to 5 days after surgery. The gold standard regiment of treatment consists of a combination of: intravitreal injection of antibiotics, topical antibiotics, and subconjuctival injection of antibiotics.
Hemorrhage can occur during or just after the surgery.The main complaint of the patient is sudden onset of pain and loss of vision. On examination, the anterior chamber is shallower than the other eye. Treatment depends on the condition of the wound. The condition is managed medically if the wound is intact, whereas surgical management is the rule if the wound is disrupted.
3) Retained lens fragments
The human lens is surrounded by a layer of tissue forming a bag. During the operation, a tear might be produced in the posterior layer of that bag, and this might lead to dropping of pieces of the lens to the posterior chamber or further deeper in the vitreous humor. The size of the retained fragment determines the seriousness and severity of the inflammation produced in the eye. A vitreoretinal surgeon is needed to extract the dropped fragment.
II. Other early complications:
1) Corneal oedema
Corneal oedema after cataract surgery is due to many causes, most commonly due to prolonged time of surgery leading to extended exposure of corneal cells to the ultrasonic power of the phaco probe. Cell injury after lengthy procedures leads to dysfunction of the cells allowing fluids to enter in between the layers of the cornea, in turn leading to corneal oedema. The oedema usually resolves after 4 to 6 weeks with adequate treatment.
2) Gapping of the wound and leakage of aqueous humor
This usually happens with large wounds, or if the wound is inadequately closed. On examination, the anterior chamber is shallower than the other eye with decreased intraocular pressure compared to the other eye. Many treatment options are available to control this complication:
a) Applying Cycloplegic eye drops and pressure bandage
b) Carbonic unhydrase inhibitors and Beta blockers eye drops to decrease the intraocular.
c) Therapeutic soft contact lenses.
d) Tissue adhesive seal to close the wound leak.
III. Late complications:
1) Elevated intraocular pressure
Surgeons use viscoelastic materials to form the anterior chamber. In some conditions the surgeon chooses to leave the anterior chamber formed by the viscoelastic material, or some parts might be incompletely removed leading to elevation of intraocular pressure. In most cases, the elevated intraocular pressure can be managed by tension lowering measures. Other etiologies behind elevated intraocular pressure following cataract surgery include: preexisting glaucoma, Hyphema, dropped lens particles and endophthalmitis.
2) Displacement and dislocation of the IOL
When the patient vigorously moves his head after operation, the implanted IOL might be displaced or dislocated. The complaint of the patient might be seeing multiple images, reflections, unwanted glare, or loss of the crispiness of vision. The surgeon will try to reposition the IOL in its correct position and fix it to ensure that this won’t happen again.
3) Posterior capsular opacification
This is by far the most common complication seen after cataract surgery. This condition is due to regrowth of cells on the posterior capsule behind the IOL leading to gradual diminution of vision again. The complication can be treated by applying ”YAG laser” to clear the part of the opacification directly in front of the visual axis resulting in immediate regaining of vision.