Elevated Intraocular Pressure Following Dalk Due To Trapped Gas In The Posterior Chamber

To present a challenging case of keratoconus that showed up with secondary acute angle closure after an uneventfull DALK surgery. There was not an  elevated intraocular pressure from a pupillary block of air in the anterior chamber but  an unexpected angle closure secondary to trapped gas in the posterior chamber.

A 27 years male patient with the complaint of low vision and strabismus was applied to our clinic. His right visual acuity was to count fingers.  There were right exotropia and keratoconus findings in biomicroscopic examination. The intraocular pressure was 6mmHg and the fundus examination was normal. The Sirius tomography  (Sirius; Costruzione Strumenti Oftalmici [CSO], Florence, Italy)  revealed   that his right corneal thinnest pachymetry was 325 with K1=67.32,  K2=69.32, Kmax=82.45 (Figure:1). An uneventfull Deep Anterior Lamellar Keratoplasty (DALK) surgery  was performed to the right eye  with a donor and recipient sizes of 7.75/7.50mm and 16 single sutures (Video:1). Air was introduced to the anterior chamber to asist the greft and donor allignment. Postoperative 1st day the patient was presented with slit anterior chamber and air only in pupillary margine (Figure:2). The anterior oct findings was consistent with iris corneal touch, angle closure and trapped gas in the posterior chamber (Figure:3). İmmediately oral acetazolamide and intravenous mannitol infusion, a 45 degree lying on back and hourly topical steroid  treatment was started. The passage of air to anterior chamber is observed and the findings subsided slowly in hours(figüre:4). The iris corneal touch was released starting from the superior quadrant (figüre:5). In 3 years follow up the final visual acuity was 0.8 with a normal optic disc.

Air trapment to the posterior chamber was reported after DMEK surgery. This case reveals that this kind of intraocular pressure rise could be seen  early postopeartive period after DALK surgery. Conservative treatment opens the angle closure secondary to trapped gas in the posterior chamber if it is noticed in its early periods.