Protecting the Corneal Endothelium Corneal Endothelium - The Challenge Claes Feinbaum Msc PhD Department of Ophthalmology Barzilai Medical Center Ashkelon, Israel 1

Protecting the endothelium during cataract surgery can be a challenge for seasoned or novice surgeons alike depending on the status of patients 2

Factors are as varied as the patients’ cases Recognized non-corneal risk factors preventing injury to corneal endothelial cells: 1. Shallow A.C. 2. Crowded A.C. 3. Density of nucleus 4. Small pupils 5. Volume of infusion 6. Amount of ultrasound used 7. Type of IOL to be implanted 3

Corneal characteristics that may cause problems 1. Older patient age characterized by a lower endothelial cell density and 2. Presence of Fuchs’ dystrophy and diabetes mellitus 4

Surgical factors to consider Decision making during the preoperative testing. In high-risk patients: 1. Performing a cataract extraction or 2. Descemet’s stripping endothelial keratoplasty (DSEK) triple procedure including: a. corneal transplant b. cataract removal c. IOL insertion 5

Patient symptoms during pre-operative examination. 1. Severity of guttae (specular reflection) 2. Stromal edema 3. Lens density 4. A.C. Depth 5. Other symptoms Examination should also include pachymetry and specular microscopy. 6

Phacoemulsification techniques and technology. 7

The phacoemulsification technique 1. Horizontal or vertical chop procedure reduces both energy used in eye and ultrasound time. 2. Benefits of ultrasound power modulation: a. greatly reduced repulsion b. decreased turbulence c. enhanced followability d. lower risk of thermal burns e. less endothelial trauma 8

Resulting in less total energy used and less endothelial cellular loss at 6 months postoperatively 9

Phaco technology:Femtosecond-assisted cataract surgery 1. The effective phaco time can be reduced from about 1 minute to less than 30 seconds 2. From an average power of about 23.5% with phaco-only to about 13.5% with Femto 10

Use of viscoelastics. Three types of viscoelastics are used in the eye depending on the patient: 11

Dispersives Viscoat, Healon D, and Ocucoat 1. Have shorter chains 2. Coat the endothelium well 3. More difficult to remove 12

Cohesives Healon, Healon 5, Provisc and Amvisc 1. Have longer chains 2. Easy to remove 3. Facilitate optimal visualization in the eye 13

Adaptives Healon 5 and DiscoVisc 1. Cohesive under low-flow conditions 2. Dispersive in high-flow conditions 14

Irrigation and aspiration 15

Of Importance Removing all nuclear fragments Identify by slit lamp evaluation, gonioscopy, and ultrasound biomicroscopy Most lens fragments found in the inferior angle 80% of patients with corneal edema diagnosed with lens fragment after day 1 postoperatively. 16

Intracameral medications. 17

Toxic anterior segment syndrome (TASS) 1. Onset 12 to 48 hours following cataract or anterior segment surgery 2. Sterile postoperative inflammatory reaction 3. Caused by a noninfectious substance entering the anterior segment 4. Causing toxic damage to the intraocular tissues 18

TASS Treatment improves after treatment with corticosteroids 19

Ocular medications implications 1. Incorrect concentrations 2. pH 3. Osmolality; a vehicle with incorrect pH or osmolality 4. Preservatives in a medication solution identified as causes. 20

Postoperative medications. 21

Medical Therapy 1. Instillation of corticosteroids prednisolone acetate 1% and difluprednate 0.05% 2. Newer delivery systems via nanoparticles and punctal plugs 3. Future medications such as Rho-kinase inhibitors 22

These were the pearls 23