Short-term Intraocular Pressure Spikes Induced by Pneumoperitoneum are Safe for the Optic Nerve in a Healthy Eye
Authors: Grosso Andrea ,   Centre for Macular Research and Allied Diseases, Torino, Italy,   Division of Ophthalmology, ‘Santo Spirito’ Hospital, Casale Monferrato, Italy, Ceruti Piero ,   Borgo Trento Hospital, University of Verona, Verona, Italy, Crowston Jonathan ,   Ophthalmology and Department of Surgery, Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia, Bert Fabrizio ,   Department of Public Health Sciences and Pediatrics University of Torino, Torino, Italy, Allaix Marco E ,   Department of Surgical Sciences, University of Torino, Torino, Italy, Bullano Alberto ,   Department of Surgical Sciences, University of Torino, Torino, Italy, Grasso Luca ,   Department of Surgical Sciences, University of Torino, Torino, Italy, Battaglino Valentina ,   Department of Ophthalmology, Torino Eye Hospital, Torino, Italy, Cavallo Enrico ,   Department of Surgical Sciences, University of Torino, Torino, Italy, Orthop Roberta Piccini ,   Department of Ophthalmology, Torino Eye Hospital, Torino, Italy, Orthop Giulio Piana ,   Department of Ophthalmology, Torino Eye Hospital, Torino, Italy, Orthop Beatrice Visentin ,   Department of Ophthalmology, Torino Eye Hospital, Torino, Italy, Siliquini Roberta ,   Department of Public Health Sciences and Pediatrics University of Torino, Torino, Italy, Morino Mario ,   Department of Surgical Sciences, University of Torino, Torino, Italy
Published: August 2018

The aim of this study was to determine the effects of the pneumoperitoneum used in colorectal procedures on peripapillary retinal nerve fibre layer (RNFL) thickness. We also analysed the dynamics of ocular anterior segment structures. In this prospective clinical pilot study, 29 patients aged between 45 and 85 years old underwent laparoscopic surgery for selected colorectal diseases. The pneumoperitoneum induced a mean intraocular pressure (IOP) increase of 4 mmHg. Visual acuity, IOP, corneal thickness, angle opening distance (AOD) and the trabeculo-iris space area (TISA) at 500 microns and 750 microns anterior to the scleral spur, RNFL thickness and visual field were measured before and after surgery using Sloan charts, Visante™ optical coherence tomography (OCT) (Zeiss, Oberkochen, Germany), Spectralis® OCT (Heidelberg Engineering, Heidelberg, Germany) and Humphrey Visual Field System® (Zeiss, Oberkochen, Germany). Patients were categorised in two groups to understand the behaviour of IOP: in group one (n=17), patients were in Trendelenburg position; in group two (n=12), patients were in reverse Trendelenburg position. The IOP was measured during surgery by the Icare® Tonometer (Icare, Vantaa, Finland) according to a standardised protocol; the IOP was measured before and after surgery by Goldmann applanation tonometer (Haag-Streit, Koniz, Switzerland). Patients with previous diagnosis of both open or angle-closure glaucoma or anterior segment anomalies were excluded. No statistically significant differences in increase of IOP were found between the two groups (p>0.05); no statistically significant differences in RNFL thickness, visual field, AOD and TISA were found before and after surgery in all patients (p>0.05). In our study we have demonstrated that a mean IOP increase of 4 mmHg over a short period of time is safe for a healthy optic nerve.