Background and objectives: Penetrating keratoplasty is a surgical procedure with a history spanning over a century. The objective is to identify the incidence and potential risk factor of graft failure after performing penetrating keratoplasty in eyes with Ahmed valve tube. Methods: This retrospective study conducted on 24 patients whom penetrating keratoplasty and glaucoma shunt surgery have been performed for them from February 2017 to December 2022 at North eye center/ Erbil city. The follow up was obtained for determining the risk factors associated with keratoplasty failure. Results: Half of the patients with glaucoma drainage devices have a successful penetrating keratoplasty surgery. Age was not a risk factor for penetrating keratoplasty failure, relative risk (RR)=0.85, CI=0.38-1.88, P=0.682). Also, the following factors were not a risk for keratoplasty failure; sex (RR=1,CI=0.45-2.23, P=1), sequence of surgery of Ahmed valve prior to penetrating keratoplasty (RR=0.57,CI=0.20-1.53, P=0.206), eye laterality (RR=1.23,95%CI=0.47-3.25, P=653), aphakia (RR=4.0,CI=0.12-136.95, P=0.215) and pseudophakia (RR=5.71,CI=0.52-62.66 P=0.154), history of vitreoretinal surgery is the risk factor for penetrating keratoplasty failure (RR=3.4,95%CI=1.63-7.10,P=0.002), chronic diseases (RR=0.79,95%CI=0.34-1.86,P=0.615) and intraocular pressure>21 mmHg (RR=1.214,95%CI=0.54-2.75,P=0.653) are also risk factors for decreasing success of penetrating keratoplasty. Conclusion: In our study, Ahmed valve is a risk factor for failure of pentrating keratoplasty surgery which is 50%. Age, gender, Ahmed valve prior to penetrating keratoplasty, lens status and operated eye were not a risk factor in pentrating keratoplasty failure in those who underwent glaucoma drainage device. Whereas, vitreoretinal surgery, chronic diseases and intraocular pressure were observed as risk factors in penetrating keratoplasty failure.
Mohammed et al. (Sun,) studied this question.