Cataract Surgery with Near Normal Eye Pressure in Patients with Diabetic Retinopathy

Near Normal Intraocular Pressure Cataract Surgery in Patients with Diabetic Retinopathy Using Active Anterior Chamber Pressure Sensing and Regulation - a Randomized Controlled Comparative Clinical Trial

Diabetes mellitus is a chronic metabolic disease that can lead to visual impairment and eye complications such as diabetic retinopathy and diabetic macular edema. Diabetics are considered a vulnerable patient group for cataract surgery, as microincision phacoemulsification (MICS) in diabetics is associated with a higher risk of postoperative swelling of the macula and cornea (macular or corneal edema). In addition, the ultrasound energy emitted during MICS, high and fluctuating intraocular pressure and the movement of surgical instruments and lens material are the main causes of surgical trauma. The medical device "Centurion Vision System" with the "Active Sentry" handpiece was developed specifically to improve the stability of the anterior chamber during surgery and to enable operations at low, almost normal physiological intraocular pressure settings.

The central question of the study is therefore, whether a stable intraocular pressure close to physiological normal conditions (28 mmHg) during surgery can lead to a reduction in surgical trauma. In this prospective and randomized study, patients suffering from diabetes and having a planned bilateral MICS are included in one of two study arms:

A) The participant is operated on with an IOP of 28 mm Hg in the better eye and an IOP of 50 mm Hg in the worse eye or B) the participant is operated on with an IOP of 28 mm Hg in the worse eye and an IOP of 50 mm Hg in the better eye.

Inclusion Criteria:

1. Indication for immediate sequential bilateral microincision cataract surgery
2. Diagnosis of Diabetes Mellitus treated with oral medication or insulin therapy and confirmed by HbA1c ≥6,5 %
3. Presence of diabetic retinopathy grade ≥1 on the international clinical diabetic retinopathy (ICDR) severity scale
4. LOCS 2-4 with no more than 1 grade difference between both eyes
5. Male or female patient aged 50 - 85 years of age at time of consent
6. Understands and agrees to comply with the study procedures and provides written informed consent as documented by signature

Exclusion Criteria:

1. Participation in another clinical trial within 30 days before pre-screening and throughout the trial
2. Prior intraocular surgery of any type
3. History of diabetic macular edema
4. Presence of macular edema, defined as central retinal thickness of >300 µm plus intraretinal or subretinal fluid on OCT within range of 1mm of foveal center
5. Presence of any retinal or choroidal disease, other than diabetes, that could affect retinal thickness
6. Known history of uveitis
7. Documented use of systemic or topical steroid or other immunosuppressive medication within the last 3 months
8. ACF >10 ph/ms. ACF difference between right and left eye > 4ph/ms
9. Difference of DRP grading between right and left eye of more than 1 grade (ICDR)
10. Inability to measure total macular volume due to, but not limed to, too dense cataract, vitreous bleeding
11. Woman of childbearing potential (WOCBP) who is breastfeeding, has a positive urine pregnancy test, is not willing to undergo a urine pregnancy test upon entering or exiting the study, intends to become pregnant during the study, or does not agree to use adequate birth control methods for the duration of the study
12. Patients in possession of an active implantable medical device (AIMD)