The Breathing Bubble Sign : The Telltale Of A Leaking Wound Following Cataract Surgery

The purpose of this paper is to discuss the techniques of cataract surgery, the settings of the phacoemulsification machine, and surgical steps that can be taken to prevent wound-related complications in a hard brown cataract. We discuss a patient who had been operated on the previous day and was observed to have a collapsed anterior chamber with a rhythmically moving or "breathing" bubble of air that was injected in the anterior chamber.

A 54 year old female patient, diabetic on oral hypoglycemic agents was operated for her hard grade 5 brown cataract. All routine steps of the surgery were uneventful, save for the higher amount of power that had to be used for the grade of the cataract. An air bubble was injected into the anterior chamber at the end of the surgery to maintain the chamber and the case was closed. 

After a thorough anterior segment evaluation to rule out any pre operative complications such as subluxation or loose zonular support or an inadequately dilating pupil the patient was planned for cataract surgery by phacoemulsification. An ultrasound B scan was done to rule out any posterior segment pathology. The patient was taken up for surgery which was relatively uneventful. The phaco machine settings had to be set very high for the emulsification of this nucleus with the power being 80 and bottle height was kept at maximum for a good anterior chamber depth and room to maneuver. 

An air bubble was injected in the end of the surgery to ensure the anterior chamber is well formed and the case was finished. 

 On careful inspection, the bubble was moving rhythmically to the patient's heartbeat,thus confirming there was no interface of fluid between the bubble and iris and between the bubble and endothelium of the cornea, transmitting the pulsations. The wound was then carefully inspected, which on slit examination revealed a sliver of peripheral iris tissue blocking the wound and hence giving us a false siedels test. On follow up, the patient's anterior chamber was shallow and a number of descemets folds were noticed loosely arranged in a centrifugal pattern. A siedel's test was negative and no active leak was detected. The bubble seemed to be the only thing holding the anterior chamber out.

The breathing bubble sign is a sign of improper sealing of the main wound in phacoemulsification. Since most or all of the aqueous has already leaked outside, with the plugging of the wound by the peripheral iris, seidels test will most likely be negative. In a seemingly uncomplicated case, this is a small, rectifiable complication. However, if missed in a hurry this will lead to post-operative hypotony that can lead to an array of other complications like maculopathy and must be looked out for.