Keratoplasty Flashcards
DSAEK - postoperative shift
0.5-1.5D hyperopic shift
DMEK - postoperative shift
hyperopic shift
Postoperative shift in DSAEK/DMEK - reasons
- Thinning of the cornea. 2. Change in posterior curvature of the cornea - adds “minus” power to the cornea
Urrets-Zavalia syndrome
Fixed dilated pupil with sector iris atrophy after penetrating keratoplasty. Parasympathetic denervation of the iris sphincter. Or ischemic of the iris and acute rise in IOP
Most common indication for penetrating keratoplasty
keratoconus
DMEK + over DSAEK
lower rejection rate, smaller incision (2.8 mm) than DSAEK (5 mm), better vision
DSAEK + over DMEK
easier to perform, recovery is faster, less rebubbling and primary failure
DMEK - over DSAEK
more difficult to perform, recovery is longer, more rebubbling and primary failure
DSAEK - over DMEK
higher rejection rate, larger incision DSAEK (5 mm) than DMEK (2.8 mm) , worse vision
% in 2014
PK 42. ALK 2. EK 56 (DSAEK 50, DMEK 6)
McCarey-Kaufman (MK) medium - storage time
4 days
most commonly used intermediate-term storage medium
Optisol GS
Optisol GS - storage time, what contains
up to 7 days. chondroitin 2.5%, dextran 1%, ascorbic acid, and vitamin B12; gentamicin, streptomycin
Primary donor failure
edematous from the first postoperative day and remains so without inflammatory signs, a deficiency of donor endothelium should be suspected
Primary donor failure - how long to wait for re-grafting
4 weeks and up to 2 months
Wound misalignment or leak - when resuturing
shallow anterior chambers and low pressures lasting longer than 3 days
PK - complications
Primary donor failure, Wound misalignment or leak, Flat chamber or iris incarceration in the wound, Endophthalmitis, Persistent epithelial defect, Elevated intraocular pressure, Recurrence of primary disease. Astigmatism, Late non–immune-mediated endothelial failure. Sutures: loosening, infectious abscesses, giant papillary conjunctivitis, vascularization
Elevated intraocular pressure after PK - when
any time
Elevated intraocular pressure after PK - first sign
loss of folds in the Descemet membrane
Epithelial rejection
minority, early in the postoperative period (1–13 months), may be asymptomatic; however, blurred vision
Subepithelial rejection
these may be asymptomatic or may cause glare or reduced vision. They resemble the infiltrates associated with adenoviral keratoconjunctivitis
Stromal rejection
more commonly after DALK, It may present as stromal infiltrates, neovascularization, or, typically, noninflitrative keratolysis within the graft–host interface
