Surgery may be required in cases where the cornea is permanently scarred or in cases refractory to maximum medical treatment. Awwad et al. [37] in 2005 described penetrating keratoplasties (PK) in thirteen quiet eyes at least three months after stopping amoebacidal treatments for AK. Final visual acuities ranged from 20/15 to 20/40, and no episodes of rejection or disease reactivation were recorded. Whilst a good outcome can be expected in eyes that have responded well to treatment, it is of course a larger challenge to maintain a graft in an eye with an ongoing infection. Nguyen et al. [38] reported 9 such cases with final acuities between 20/15 and 20/50 with no recurrences after 17 months of followup. In 2007, Parthasarathy and Tan [39] reported a case of deep lamellar keratoplasty (DLK) for treatment of refractive AK in 2007, with the patient eventually retaining 20/20 vision. This has the obvious advantage of maintaining an intact globe intraoperatively, which serves to reduce intraocular entry of organisms and maintains an intact endothelium, which may improve graft survival. This has since been incorporated into clinical practice. In an outbreak of AK in Singapore reported in 2009 by Por et al. [40], 11 out of 43 eyes required therapeutic DLK, and one required therapeutic PK. Recurrence of disease was seen in one DLK, which required further PK surgery. Final visual acuities were again mixed, with only 25 of the eyes obtaining 20/40 or better. Szentmáry et al., in a recent review [41], reported improved outcomes of keratoplasty in those procedures performed after three months of keratitis inactivity, suggesting that surgery should be performed later in the clinical course if possible.