Corneal Endothelium clinical notes

✍️ Don’t proliferate but cell loss is compensated for by an increase in size( polymegethism) when the cells become more irregular in shape (polymorphism ).

✍️ Endothelial cells have sodium/potassium and bicarbonate pumps that cause water to be pumped out of the stroma

✍️ the optimum level of stromal hydration (78% water) maintained by endothelial cells for corneal transparency.

✍️ Persistently high intraocular pressure (IOP) damages the endothelium and water will then enter the stroma and the cornea will swell and become hazy.

✍️ The cell density (cells per unit area) of the endothelium decreases normally with aging because of cell disintegration

☝️6000 cells /mm2 at birth

☝️3000 to 4000 cells/mm2 in children

☝️ 2400 to 3200 in adult

☝️1000 to 2000 cells/mm2 at age 80 years.

☝️900 to 1000 cells/ mm2 Minimum legible cell count for phacoemulsification

☝️ 600 cells/mm2. The minimum cell density necessary for corneal transparency

✍️ The corneal thickness of newborn infants is highest during the first 24 hours after birth and decreases significantly after 48 hours.

✍️ This thinning process of newborns continues steadily until the age of 3, at which time the thickness of the adult cornea is attained.

✍️ The rate of corneal deswelling after oedema, measured as the percentage recovery per hour, is significantly higher in young patients than in older ones.

✍️ Moderate damage of the corneal endothelium during surgery may lead to a transient increase in corneal thickness as measured by pachymetry

✍️ most of patients regained preoperative corneal thickness values after 4 weeks, whereas others have found increases to be sustained up to 6 months or even 1 year postoperatively

 Phacoemulsification endothelial risk matrix:

☝️ the severity of FED( FUCHs)

☝️endothelial cell count

☝️coefficient of variability

☝️hexagonality

☝️ultrasound pachymetry

☝️anterior chamber depth

☝️LOCS III

☝️cataract grade classification.

❤️ Look at the attached pics of the post for the table

✍️ Low risk (0 to 5).

☝️soft cataracts

☝️normal ACD

☝️few guttata

☝️no other corneal abnormalities

☝️Phaco procedure with controlled fluidics can be performed

✍️ Moderate risk (6 to 10).

☝️moderate FED

☝️ a cell count above 1,500 cells/mm2

☝️a cataract LOCS III grade 4.

☝️ prechopping, ultrasound-sparing techniques (femtosecond laser-assisted, Akahoshi prechop) should be used.

☝️dispersive OVD injection should be repeated every three to five units of effective phaco time during quadrant removal.

✍️ High risk (Score 11 to 19).

☝️ Zero-ultrasound techniques (ECCE and SICS ) should be considered in these cases

☝️ avoiding contact between the nucleus and the endothelium, as endothelial contact can be just as damaging to the compromised endothelium as a normal phaco.

☝️ Viscodynamic extraction is another zero-phaco technique that can be used.

• a sclero-corneal tunnel

• small fragmentation of the nucleus using any method (femtosecond laser or Akahoshi prechopper)

• fragment removal through the sclerocorneal wound while dispersive viscoelastic is injected liberally into the anterior chamber to push the fragments out of the eye.

✍️ Very high risk (20+).

☝️ a triple procedure is recommended with
endothelial keratoplasty or PKP

🛑 LOCS III = lens opacity classification system III