{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T08:19:16Z","timestamp":1777709956504,"version":"3.51.4"},"reference-count":45,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T00:00:00Z","timestamp":1768521600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Surgery performed in the steep Trendelenburg position is considered potentially detrimental to ocular structures. This study aimed to evaluate morphological changes in the anterior segment during robot-assisted laparoscopic prostatectomy (RALP). Methods: This was a single-center, prospective observational study involving 60 eyes of 30 consecutive patients undergoing RALP between May and November 2021. Anterior segment images were obtained using a Smart Eye Camera before surgery (supine and awake), during surgery (supine and steep Trendelenburg under anesthesia), and after surgery (supine). Assessed parameters included the iridocorneal angle, the ratio of peripheral anterior chamber depth to peripheral corneal thickness based on Van Herick Plus grading, and pupil diameter. Each parameter in the steep Trendelenburg position under anesthesia was compared with measurements obtained in the supine position under anesthesia and in the awake condition. The primary outcome was the comparison of anterior segment morphological changes between the supine and steep Trendelenburg positions during RALP. Results: Upon transition to the steep Trendelenburg position, anterior chamber depth significantly decreased (p &lt; 0.001), recovering after returning to the supine position. The proportion of eyes classified as having narrowed anterior chambers increased significantly (p &lt; 0.001), with more than 60% showing shallower chambers relative to preoperative measurements. Extreme anterior chamber narrowing occurred in 3 out of 410 intraoperative assessments (1%). Pupils were uniformly constricted under anesthesia. Conclusions: Steep Trendelenburg positioning significantly reduces anterior chamber depth. This morphological alteration may contribute to the marked increase in intraocular pressure observed during RALP.<\/jats:p>","DOI":"10.3390\/jcm15020731","type":"journal-article","created":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T08:08:21Z","timestamp":1768550901000},"page":"731","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Prospective Evaluation of Ocular Anterior Segment Morphology Changes in the Steep Trendelenburg Position During Robotic-Assisted Laparoscopic Prostatectomy"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5270-3021","authenticated-orcid":false,"given":"Mototaka","family":"Sato","sequence":"first","affiliation":[{"name":"Department of Urology, Toyonaka Municipal Hospital, Toyonaka 5608565, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3422-8578","authenticated-orcid":false,"given":"Eisuke","family":"Shimizu","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Keio University School of Medicine, Shinjyuku-ku, Tokyo 1608582, Japan"},{"name":"OUI Inc., Minato-ku, Tokyo 1070062, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Atsuki","family":"Matsukawa","sequence":"additional","affiliation":[{"name":"Department of Urology, Toyonaka Municipal Hospital, Toyonaka 5608565, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ryoya","family":"Mizuno","sequence":"additional","affiliation":[{"name":"Department of Urology, Toyonaka Municipal Hospital, Toyonaka 5608565, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Satoshi","family":"Kamido","sequence":"additional","affiliation":[{"name":"Medical Center for Translational Research, Department of Medical Innovation, Osaka University Hospital, Suita 5650871, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7152-5176","authenticated-orcid":false,"given":"Takahiro","family":"Mizukami","sequence":"additional","affiliation":[{"name":"Fuchu Eye Center, Fuchu Hospital, Izumi 5940076, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Norichika","family":"Ueda","sequence":"additional","affiliation":[{"name":"Department of Urology, Osaka University Graduate School of Medicine, Suita 5650871, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoko","family":"Fujimoto","sequence":"additional","affiliation":[{"name":"Fujimoto Ophthalmic Clinic, Osaka 5460013, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0550-8845","authenticated-orcid":false,"given":"Norihide","family":"Tei","sequence":"additional","affiliation":[{"name":"Department of Urology, Toyonaka Municipal Hospital, Toyonaka 5608565, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Osamu","family":"Miyake","sequence":"additional","affiliation":[{"name":"Department of Urology, Toyonaka Municipal Hospital, Toyonaka 5608565, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,16]]},"reference":[{"key":"ref_1","first-page":"229","article-title":"Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries","volume":"74","author":"Bray","year":"2024","journal-title":"CA Cancer J. Clin."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/j.eururo.2016.12.025","article-title":"Management of Prostate Cancer in Elderly Patients: Recommendations of a Task Force of the International Society of Geriatric Oncology","volume":"72","author":"Droz","year":"2017","journal-title":"Eur. Urol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1016\/j.eururo.2024.11.013","article-title":"Recent Patterns and Trends in Global Prostate Cancer Incidence and Mortality: An Update","volume":"87","author":"Schafer","year":"2025","journal-title":"Eur. Urol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"729","DOI":"10.1016\/j.eururo.2016.08.047","article-title":"Temporal Trends and the Impact of Race, Insurance, and Socioeconomic Status in the Management of Localized Prostate Cancer","volume":"71","author":"Gray","year":"2017","journal-title":"Eur. Urol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e212265","DOI":"10.1001\/jamanetworkopen.2021.2265","article-title":"Comparison of 1-Year Health Care Costs and Use Associated with Open vs Robotic-Assisted Radical Prostatectomy","volume":"4","author":"Okhawere","year":"2021","journal-title":"JAMA Netw. Open"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Mendel, E., Stoicea, N., and Rao, R. (2017). Revisiting Postoperative Vision Loss following Non-Ocular Surgery: A Short Review of Etiology and Legal Considerations. Front. Surg., 4.","DOI":"10.3389\/fsurg.2017.00034"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Taketani, Y., Mayama, C., and Suzuki, N. (2015). Transient but significant visual field defects after robot-assisted laparoscopic radical prostatectomy in deep tRendelenburg position. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0123361"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Blecha, S., Harth, M., Schlachetzki, F., Zeman, F., Blecha, C., Flora, P., Burger, M., Denzinger, S., Graf, B.M., and Helbig, H. (2017). Changes in intraocular pressure and optic nerve sheath diameter in patients undergoing robotic-assisted laparoscopic prostatectomy in steep 45\u00b0 Trendelenburg position. BMC Anesthesiol., 17.","DOI":"10.1186\/s12871-017-0333-3"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1016\/j.jclinane.2014.01.014","article-title":"Cardiac and hemodynamic consequences during capnoperitoneum and steep Trendelenburg positioning: Lessons learned from robot-assisted laparoscopic prostatectomy","volume":"26","author":"Rosendal","year":"2014","journal-title":"J. Clin. Anesth."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1213\/ane.0b013e3181a9098f","article-title":"The effects of steep trendelenburg positioning on intraocular pressure during robotic radical prostatectomy","volume":"109","author":"Awad","year":"2009","journal-title":"Anesth. Analg."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1136\/bjophthalmol-2013-303536","article-title":"The effect of steep Trendelenburg positioning on intraocular pressure and visual function during robotic-assisted radical prostatectomy","volume":"98","author":"Hoshikawa","year":"2014","journal-title":"Br. J. Ophthalmol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1213","DOI":"10.1016\/j.juro.2014.10.094","article-title":"The effect of the modified Z trendelenburg position on intraocular pressure during robotic assisted laparoscopic radical prostatectomy: A randomized, controlled study","volume":"193","author":"Raz","year":"2015","journal-title":"J. Urol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1097\/IJG.0000000000000302","article-title":"Intraocular Pressure During Robotic-assisted Laparoscopic Procedures Utilizing Steep Trendelenburg Positioning","volume":"24","author":"Mondzelewski","year":"2015","journal-title":"J. Glaucoma"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1111\/iju.14183","article-title":"Prospective evaluation of visual function in patients with ocular diseases after robot-assisted laparoscopic prostatectomy","volume":"27","author":"Kakutani","year":"2020","journal-title":"Int. J. Urol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1027397","DOI":"10.1155\/2018\/1027397","article-title":"The Effect of Steep Trendelenburg Positioning on Retinal Structure and Function during Robotic-Assisted Laparoscopic Procedures","volume":"2018","author":"Hirooka","year":"2018","journal-title":"J. Ophthalmol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"975","DOI":"10.1213\/ANE.0000000000004547","article-title":"The Effect of Increased Intraocular Pressure During Steep Trendelenburg Positioning in Robotic Prostatectomy and Hysterectomy on Structural and Functional Ocular Parameters","volume":"130","author":"Awad","year":"2020","journal-title":"Anesth. Analg."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Shirono, Y., Takizawa, I., Kasahara, T., Maruyama, R., Yamana, K., Tanikawa, T., Hara, N., Sakaue, Y., Togano, T., and Nishiyama, T. (2020). Intraoperative intraocular pressure changes during robot-assisted radical prostatectomy: Associations with perioperative and clinicopathological factors. BMC Urol., 20.","DOI":"10.1186\/s12894-020-00595-5"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Yoo, Y.C., Kim, N.Y., Shin, S., Choi, Y.D., Hong, J.H., Kim, C.Y., Park, H., and Bai, S.J. (2015). The Intraocular Pressure under Deep versus Moderate Neuromuscular Blockade during Low-Pressure Robot Assisted Laparoscopic Radical Prostatectomy in a Randomized Trial. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0135412"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1007\/s12630-014-0112-2","article-title":"Increase in intraocular pressure is less with propofol than with sevoflurane during laparoscopic surgery in the steep Trendelenburg position","volume":"61","author":"Yoo","year":"2014","journal-title":"Can. J. Anaesth."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1089\/end.2014.0381","article-title":"The effect of dexmedetomidine on intraocular pressure increase in patients during robot-assisted laparoscopic radical prostatectomy in the steep Trendelenburg position","volume":"29","author":"Kim","year":"2015","journal-title":"J. Endourol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1007\/s11255-016-1449-y","article-title":"Does steep Trendelenburg positioning effect the ocular hemodynamics and intraocular pressure in patients undergoing robotic cystectomy and robotic prostatectomy?","volume":"49","author":"Ozcan","year":"2017","journal-title":"Int. Urol. Nephrol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1097\/WNO.0b013e31815b9f67","article-title":"Posterior ischemic optic neuropathy after minimally invasive prostatectomy","volume":"27","author":"Weber","year":"2007","journal-title":"J. Neuro-Ophthalmol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"998","DOI":"10.1016\/S0161-6420(00)00022-1","article-title":"Epidemiology of angle-closure glaucoma: Prevalence, clinical types, and association with peripheral anterior chamber depth in the Egna-Neumarket Glaucoma Study","volume":"107","author":"Bonomi","year":"2000","journal-title":"Ophthalmology"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Wu, S.C., Lee, Y.S., Wu, W.C., and Chang, S.H. (2016). Chamber depth and angle-closure glaucoma after central retinal vein occlusion. BMC Ophthalmol., 16.","DOI":"10.1186\/s12886-016-0256-7"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1213\/XAA.0000000000000935","article-title":"Postoperative Acute Angle-Closure Glaucoma: A Rare but Serious Complication: A Case Report","volume":"12","author":"Roor","year":"2019","journal-title":"A A Pract."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1167\/tvst.10.4.28","article-title":"Smart Eye Camera: A Validation Study for Evaluating the Tear Film Breakup Time in Human Subjects","volume":"10","author":"Shimizu","year":"2021","journal-title":"Transl. Vis. Sci. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Shimizu, E., Yazu, H., Aketa, N., Yokoiwa, R., Sato, S., Yajima, J., Katayama, T., Sato, R., Tanji, M., and Sato, Y. (2021). A Study Validating the Estimation of Anterior Chamber Depth and Iridocorneal Angle with Portable and Non-Portable Slit-Lamp Microscopy. Sensors, 21.","DOI":"10.3390\/s21041436"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"100906","DOI":"10.1016\/j.xops.2025.100906","article-title":"Validation of an Artificial Intelligence-Based Anterior Chamber Depth Estimation Using a Smartphone-Compatible Slit Lamp Device","volume":"6","author":"Mizukami","year":"2025","journal-title":"Ophthalmol. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1167\/tvst.10.6.19","article-title":"Automatic Anterior Chamber Angle Classification Using Deep Learning System and Anterior Segment Optical Coherence Tomography Images","volume":"10","author":"Li","year":"2021","journal-title":"Transl. Vis. Sci. Technol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"551","DOI":"10.1007\/s10384-012-0180-1","article-title":"Hong\u2019s grading for evaluating anterior chamber angle width","volume":"56","author":"Kim","year":"2012","journal-title":"Jpn. J. Ophthalmol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"931","DOI":"10.18240\/ijo.2021.06.20","article-title":"Intraocular pressure modifications in patients with acute central\/hemicentral retinal vein occlusions","volume":"14","year":"2021","journal-title":"Int. J. Ophthalmol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"960","DOI":"10.1136\/bjophthalmol-2018-312132","article-title":"\u2018Van Herick Plus\u2019: A modified grading scheme for the assessment of peripheral anterior chamber depth and angle","volume":"103","author":"Sihota","year":"2019","journal-title":"Br. J. Ophthalmol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1007\/s11701-023-01771-z","article-title":"Systematic review of the ophthalmic complications of robotic-assisted laparoscopic prostatectomy","volume":"18","author":"Rabinowitz","year":"2024","journal-title":"J. Robot. Surg."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1551","DOI":"10.1213\/ANE.0000000000002544","article-title":"Physiology and Role of Intraocular Pressure in Contemporary Anesthesia","volume":"126","author":"Kelly","year":"2018","journal-title":"Anesth. Analg."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2364","DOI":"10.1016\/j.ophtha.2012.06.002","article-title":"Optic neuropathy after vitrectomy for retinal detachment: Clinical features and analysis of risk factors","volume":"119","author":"Bansal","year":"2012","journal-title":"Ophthalmology"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1016\/S1350-9462(01)00005-2","article-title":"Blood flow in the optic nerve head and factors that may influence it","volume":"20","author":"Hayreh","year":"2001","journal-title":"Prog. Retin. Eye Res."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2115","DOI":"10.1113\/JP273557","article-title":"Effect of gravity and microgravity on intracranial pressure","volume":"595","author":"Lawley","year":"2017","journal-title":"J. Physiol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1152\/japplphysiol.00102.2017","article-title":"The impact of ocular hemodynamics and intracranial pressure on intraocular pressure during acute gravitational changes","volume":"123","author":"Nelson","year":"2017","journal-title":"J. Appl. Physiol."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Nelson, E.S., Myers, J.G., Lewandowski, B.E., Ethier, C.R., and Samuels, B.C. (2020). Acute effects of posture on intraocular pressure. PLoS ONE, 15.","DOI":"10.1371\/journal.pone.0226915"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"10","DOI":"10.3357\/AMHP.4653.2017","article-title":"Intracranial and Intraocular Pressure During Various Degrees of Head-Down Tilt","volume":"88","author":"Mulder","year":"2017","journal-title":"Aerosp. Med. Hum. Perform."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"764","DOI":"10.1093\/bja\/89.5.764","article-title":"Sevoflurane and propofol decrease intraocular pressure equally during non-ophthalmic surgery and recovery","volume":"89","author":"Deusch","year":"2002","journal-title":"Br. J. Anaesth."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1016\/j.cmet.2012.11.013","article-title":"Long-term space flight simulation reveals infradian rhythmicity in human Na(+) balance","volume":"17","author":"Rakova","year":"2013","journal-title":"Cell Metab."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1283","DOI":"10.1001\/archophthalmol.2011.272","article-title":"Anterior chamber depth, iridocorneal angle width, and intraocular pressure changes after phacoemulsification: Narrow vs open iridocorneal angles","volume":"129","author":"Huang","year":"2011","journal-title":"Arch. Ophthalmol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1007\/s11701-018-0857-7","article-title":"Are you seeing this: The impact of steep Trendelenburg position during robot-assisted laparoscopic radical prostatectomy on intraocular pressure: A brief review of the literature","volume":"13","author":"Ackerman","year":"2019","journal-title":"J. Robot. Surg."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"3740","DOI":"10.1167\/iovs.16-19600","article-title":"Distribution of Anterior Chamber Angle Width and Correlation with Age, Refraction, and Anterior Chamber Depth-The Gutenberg Health Study","volume":"57","author":"Schuster","year":"2016","journal-title":"Investig. Ophthalmol. Vis. Sci."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/2\/731\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T08:39:00Z","timestamp":1768552740000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/2\/731"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,16]]},"references-count":45,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["jcm15020731"],"URL":"https:\/\/doi.org\/10.3390\/jcm15020731","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,16]]}}}