Outcome of penetrating keratoplasty in pseudophakic bullous keratopathy

Introduction: To study the outcome of penetrating keratoplasty in pseudophakic bullous keratopathy in terms of visual acuity, graft survival, complications and to identify prognostic factors. Materials and Methods: This was a hospital based, prospective interventional study, which included 24 eyes of 24 patients with pseudophakic bullous keratopathy who underwent penetrating keratoplasty with interrupted sutures by single corneal surgeon. Eyes with posterior chamber IOL were retained, eyes with anterior chamber IOL were explanted without IOL exchange. Cases were followed upto 6 months. The outcome was assessed in terms of visual acuity, graft survival, complications and post keratoplasty astigmatism as depicted on corneal topography at the end of 6 months. Results: Out of 24 cases, 5 cases were of regraft, 1 case was lost to follow up. Percentage of cases gaining visual acuity of 6/60 or more was 60.86%, clear grafts were 87%, graft failure was 13%. Incidence of post penetrating keratoplasty glaucoma was 30.43%. Astigmatism ranged from 6 to 13 dioptres as a difference between simulate keratometric value of steep meridian and flat meridian on corneal topography at 6 months. Conclusion: Penetrating keratoplasty in pseudophakic bullous keratopathy has good short term graft survival and moderate visual recovery. Retained posterior chamber IOL helped in better visual outcome. Glaucoma and immunological rejection were main causes for graft failure. Quality of donor tissue improves the outcome of penetrating keratoplasty. Introduction Normal cornea is transparent due its peculiar anatomical and physiological properties, forming major refracting surface of the eye. It can lose its ability to refract light due opacification or distortion of its contour. Individuals with corneal blindness are of relatively younger age group, hence in terms of total blind years, impact of corneal blindness is greater. According to World Health Organization, 2009 report corneal blindness is the world’s fourth leading cause of blindness. In India it accounts for 7% of total blindness. It is estimated that number of corneally blind individual in India will be around 10.6 million by 2020. Cataract surgery is the major surgical intervention in ophthalmology. Corneal edema following cataract surgery with IOL is known as pseudophakic bullous keratopathy (PBK). Regardless of type cataract surgery with IOL implantation, continuing endothelial cell loss greater than usual 1% per year occurs in patient undergoing cataract extraction. Corneal edema usually develops when endothelial cell density falls below 500/mm. The incidence of PBK had increased progressively between 1980 – 1995 and become most frequent indication, around 26% for penetrating keratoplasty. The emergence of PBK as most common indication for penetrating keratoplasty (PK), correlates well with dramatic increase in number of cataract surgery with IOL implantation performed since early 1980. During early 1980’s, use of Iris claw and rigid closed loop anterior chamber IOL’s resulted in increased incidence of PBK. However there is decreasing trend because of obsolescence of older design and use of flexible open loop anterior chamber IOL. Also posterior chamber IOL has become the predominant form of implant used. Corneal edema with modern implant is likely to be due to surgical trauma and susceptible corneal endothelium rather than direct physical damage to corneal endothelium by the implant itself. The incidence of PBK after intracapsular cataract extraction has been reported as high as 6% whereas after extracapsular extraction with anterior chamber IOL at one year to be 1.2%, with Iris claw IOL 1.5% and with posterior chamber IOL to be 0.06%. Specular microscopy studies of patient who underwent cataract extraction with IOL have found endothelial cell loss which varies from 7% to 62%. Article Info Received: 4th February, 2019 Accepted: 6th May, 2019 Published Online: 9th September, 2019