A Comparison of Intraocular Pressures (IOP) During Prolonged Trendelenburg Positioning in Morbidly Obese and Thin Patients

Eye pressure will be measured at protocol specified intervals.

Inclusion Criteria:

1. Subjects undergoing prolonged procedures (scheduled >3hr) in steep Trendelenburg
position (eg. robotic prostatectomy, hysterectomy, cystectomy)

2. Morbidly obese subjects: BMI ≥ 35 kg/m2

3. Thin subjects: BMI ≤ 30 kg/m2

4. Age 18-70

5. ASA (American Society of Anesthesiologists) physical status classification I, II, or
III

Exclusion Criteria:

1. Known history of glaucoma

2. Note:if initial IOP is noted to be >21mmHg (millimeters of mercury), patient will be
excluded from study and an ophthalmology consultation will be obtained.Surgery will
not be postponed.

3. Recent use of IOP lowering topical ophthalmic agents

4. Allergy to latex or proparacaine hydrochloride ophthalmic solution

5. Patients with active corneal epithelial defects or history of recurrent corneal
erosion

6. Patients with underlying disorders that can directly increase intraocular pressure
(thyroid eye disease, intra orbital tumors, orbital vascular malformation,
Sturge-Weber disease, carotid or dural cavernous arteriovenous malformation,
cavernous sinus pathology)

7. History of corneal surgery, to include LASIK (laser-assisted in-situ keratomileusis)

8. Any eye surgery within prior 1 month

9. Known pregnancy

10. Cognitive impairment