Clinical Notes on Penetrating keratoplasty

✍️Optical

☝️to establish a clear visual axis

☝️reduce distortion that cannot be corrected with other means.

✍️ Diseased cornea

☝️keratoconus

☝️bullous keratopathy

☝️Fuchs endothelial dystrophy and other dystrophies

☝️scarring from trauma

☝️refractory infection.

✍️ Therapeutic

☝️removal of diseased tissue may be necessary for advanced microbial keratitis that is not responsive to antimicrobial therapy (fungal).

✍️ Tectonic

☝️provide structural support for corneal thinning, or imminent or actual perforation.

 Penetrating keratoplasty Preoperative considerations:

✍️It is important to evaluate and treat poor prognostic factors prior to surgery.

☝️blepharitis

☝️trichiasis

☝️entropion

☝️ectropion

☝️dry eye disease

☝️conjunctivitis

☝️corneal neovascularization( the worse the
prognosis)

• the extent (number of involved clock hours )
• stromal depth of vessels

☝️previous surgery(previous failed graft)

☝️glaucoma(controlled before surgery)

☝️uveitis(controlled before and after surgery)

☝️visual potential(retinal, macular, optic nerve dysfunction)

☝️pre-existing cataract consider triple procedure
(PKP, cataract extraction, and IOL insertion).

 Penetrating keratoplasty Intraoperative management notes:

✍️Surgery performed under local or general anaesthetic but general preferred as less intraoperative orbital pressure

✍️ topical miotic (pilocarpine 2% or mydriatics if combined cataract surgery is planned.

✍️ Inspect the graft material for any obvious defects (media and graft should be clear).

✍️ Consider stabilization of the eye with a scleral fixation ring (Flieringa ring) if the eye is aphakic (to prevent scleral collapse).

✍️ Select host bed and donor graft size.

☝️a larger graft (>8.5 mm)

• greater risk of glaucoma and vascularization and rejection

☝️ smaller grafts (<6.5 mm)

• greater risk astigmatism

✍️ In keratoconus the size and location of the cone must be taken into account.

✍️ In general a 7.5 mm recipient bed size is suitable for most cases with the graft centred on the cornea.

✍️ The graft size should be 0.25–0.5 mm larger than the recipient bed.

✍️ Manual or automated trephines are available to prepare the host and donor buttons.

✍️ Suturing of the donor to the graft is carried out

☝️ four cardinal sutures are placed at 12, 6, 3 and 9 o’clock with 10/0 nylon.

☝️Additional sutures are placed either interrupted alone (total of 16–24 bites) or continuous running, or a combination of interrupted (8–16) and a continuous running suture.
☝️ The depth of the suture should be to 90% corneal thickness.

☝️ All knots should be buried in the host lip .

 Penetrating keratoplasty Postoperative management notes:

✍️ Medications

☝️ Topical steroids (reduce the risk of graft rejection.

• The intensity of treatment should be tailored to the individual and the perceived risk of rejection.

• Drops are often instilled every 1–2hours for the first few days after surgery

• reduced to QDS for several weeks

• slowly tapered down to stopping over 1year or more if necessary.

☝️ Prophylactic topical antibiotic drops (in the first few weeks after surgery).

☝️Oral acyclovir (400 mg BD) prophylaxis in patients who have previously had HSK disease.

☝️Oral steroid and immunosupression (high-risk cases)

✍️ Follow-ups

☝️tailored to the patient and their disease process.

☝️normally in the following sequence

• day 1 postoperative

• 1week

• 2weeks

• 1month postoperative

• monthly for 2–3 months

• every 3–6 months thereafter

☝️emphasize to the patient prompt attendance if there are problems postoperatively.

✍️ Suture removal notes

☝️ Loose or broken interrupted sutures should be promptly removed (the risk of infection or graft rejection).

☝️A broken continuous suture should be spliced if it is too early to remove it.

☝️Sutures are normally left in situ for at least 1 year

☝️depending on astigmatism and wound healing they are removed selectively or completely.

✍️ Contact lenses notes

☝️ Rigid gas-permeable lenses may be needed to correct high astigmatism once all sutures have been removed.

☝️ Refractive procedures can also be used to reduce post-graft astigmatism.