Bilateral angle closure glaucoma following general anaesthesia.

Angle closure glaucoma is one of the ophthalmic emergencies and treatment has to be given at the earliest. It is a rare complication of general anesthesia. A female patient underwent Hysterectomy under general anesthesia. Following this, patient developed bilateral angle closure glaucoma. This patient was treated with antiglaucoma medications followed by YAG laser iridotomy and patient regained vision.

A female patient, aged 42 years underwent the trans-abdominal hysterectomy with Bilateral Salpingo oophrectomy under general anesthesia for fibroid uterus. Postoperatively, she had persistent vomiting and complained of dimness of vision. She was referred to Ophthalmic Department on 3rd postoperative day for dimness of vision. On examination, she had mild circum corneal congestion and mid dilated pupil in both eyes. There was no discharge from the eyes. Anterior chamber was looking shallow. Her vision was 6/60 in both eyes. Intraocular pressure by applanation was 45 mmHg in both eyes. On Gonioscopy, angle in all quadrants were Grade I (Shaffer Classification).

2% pilocarpine 6 times, 0.5% Timolol maleate twice daily, along with acetazolamide 500 mg twice a day was administered. 500 ml of 20% Mannitol was given by intravenous drip daily. On 3rd day of review, she had 6/24 vision in both eyes. Intraocular pressure dropped to 22 mmHg. The patient was discharged and asked to come for review as out-patient. One week later, when she came for review, eyes were quiet. YAG laser iridotomy was done in both eyes at 10 O’clock in right eye and 1 O’clock in left eye. Brimonidine eye drops twice daily and dexamethasone 0.1% eye drops were administered 4 times a day for 1-week. After 1-week she came for review. Her uncorrected vision improved to 6/12 in both eyes. Her vision in right eye improved to 6/6 with - 0.25 D Sph-1D cyl 100°. Left eye vision also improved to 6/6 with - 1D cyl 80°. She was given near the vision addition of + 1.25 D Sph. IOP in right eye was 20 mmHg and in left eye it was 19 mmHg. Her eyes were white and without any symptoms.

Discussion

Acute angle-closure glaucoma (AACG) occurs in predisposed individuals when the pupil is mid dilated. Drugs with α1 adrenergic or anticholinergic effects can precipitate attacks of AACG mainly by mydriasis. This causes paralysis of ciliary muscle tone which causes aqueous outflow resistance through trabecular meshwork. Atropine, adrenaline, ephedrine are the common drugs used during general anesthesia that precipitate angle closure. These drugs are commonly used when there is airway obstruction or buckling of the endotracheal tube.[1]

Atropine is often used to treat bradycardia, especially related to general anesthesia. Postoperatively AACG was reported in patients after general anesthesia for abdominal, orthopedic, facial and endoscopic surgery.[2] In predisposed individuals (hypermetropia, shallow anterior chamber, thick lens) anticholinergic drugs such as atropine, scopolamine and muscle relaxants and adrenergic drugs such as ephedrine, epinephrine can precipitate angle closure attack.[3] Moreover, the preoperative period causes the risk of psychological stress and darkness induced mydriasis might increase the risk of glaucoma attack. If anesthetists perform oblique pen torch test to assess the depth of the anterior chamber during preanesthetic evaluation, angle closure attack can be managed better in patients at risk.[4]

In the present case, the delay in referral to Ophthalmologist is due to masking of pain by sedation and the redness in eyes were not noticed because the patient was keeping her eye closed due to the same reason.

Conclusion

Since symptoms of AACG may be overlooked or misinterpreted in a sedated or comatose patient, any patient who has a red eye and a subjective vision loss in the postoperative period should be examined urgently.