EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/137624
52 EW RESIDENTS June 2013 EyeWorld journal club Review of "Corneal endothelial damage after cataract surgery in eyes with pseudoexfoliation syndrome" by Rajen Desai, MD, Dilraj Grewal, MD, Mahsa Sohrab, MD, and Dmitry Pyatetsky, MD, residency program director, Northwestern University Feinberg School of Medicine, Chicago Dmitry Pyatetsky, MD Not much has been written about pseudoexfoliation endotheliopathy, and I asked the Northwestern residents to review this month's JCRS paper regarding cell loss in eyes with pseudoexfoliation. David F. Chang, MD, chief medical editor P seudoexfoliation syndrome (PXF) is a systemic disorder characterized by accumulation of fibrillar material containing basement membrane components in the anterior segment of the eye, among other organ systems. Studies have suggested that the endothelial changes in PXF could represent an abnormal or unstable endothelium that is more vulnerable to the effects of intraocular surgery or raised in- From left to right: Dilraj Grewal, MD, Dmitry Pyatetsky, Mahsa Sohrab, MD, and Rajen Desai, MD Source: Dmitry Pyatetsky, MD Corneal endothelial damage after cataract surgery in eyes with pseudoexfoliation syndrome Ken Hayashi, MD, Shin-ichi Manabe, MD, Koichi Yoshimura, MD, Hiroyuki Kondo, MD J Cataract Refract Surg (June) 2013; 39:882-888 Purpose: To compare corneal endothelial cell damage and ocular inflammation after cataract surgery between eyes with and without pseudoexfoliation (PXF). Setting: Hayashi Eye Hospital, Fukuoka, Japan. Design: Nonrandomized comparative study. Methods: This study comprised eyes with PXF (PXF group) and agematched eyes without PXF (non-PXF group) scheduled for phacoemulsification. Preoperatively and 1 and 3 months postoperatively, corneal endothelial cell density (ECD) and central corneal thickness (CCT) were measured using a specular microscope. Flare intensity was measured using a flare meter, and central macular thickness was measured using optical coherence tomography. Results: Each group had 36 eyes. The mean ECD was significantly lower in the PXF group than in the non-PXF group preoperatively and postoperatively (P≤.0250). The percentage of endothelial cell loss was significantly greater in the PXF group than in the non-PXF group (P≤.0216); the percentage was 9.0% in the PXF group and 3.4% in the non-PXF group 3 months postoperatively. The mean CCT was similar between groups throughout the follow-up period; however, the percentage increase in CCT was significantly greater in the PXF group than in the non-PXF group 1 month postoperatively (P=.0152). Flare intensity and foveal thickness did not differ significantly between groups throughout the follow-up period (P≥.3079). Conclusions: Corneal endothelial cell loss and a transient increase in CCT were greater after cataract surgery in eyes with PXF than in eyes without PXF. Thus, because the corneal endothelium in eyes with PXF is vulnerable to cataract surgery, careful surgical procedures are necessary. Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned. traocular pressure.1 PXF endotheliopathy is further characterized histopathologically by pronounced endothelial cell loss, fibroblastic transformation, melanin phagocytosis, and a diffuse thickening of Descemet's membrane with formation of irregular excrescences, changes that could explain the propensity to develop corneal edema.2,3,4,5,6 Other reports have suggested that hypoperfusion of the iris, anterior chamber hypoxia, and an altered composition of the aqueous humor caused by a breakdown of the blood-aqueous barrier could also be responsible for the endothelial changes seen in PXF.7,8 Whether such PXF endotheliopathy is exacerbated by phacoemulsification surgery is the backdrop for a new study from Hiyashi et al.9 The authors present the results of a prospective, comparative study evaluating the effect of cataract surgery on corneal endothelial cell count and rates of postoperative inflammation between 36 eyes with mild PXF and 36 eyes without PXF. In each group, corneal endothelial cell count (ECD) and central corneal thickness (CCT), flare intensity, and central foveal thickness were evaluated preoperatively and at one and three months postoperatively using a specular microscope, flare meter, and optical coherence tomography (OCT), respectively. Excluded were eyes with pre-existing corneal, macular, or vitreous pathology, planned extracapsular cataract extraction, prior history of ocular inflammation or surgery, and poor dilation (<4.0 mm). Control patients without PXF were age-matched to within five years of those in the PXF group, and in all bilateral cases, only the first operated eye was included in the analysis. Of the 40 originally recruited eyes in the PXF group, 13 had associated glaucoma. All eyes received the same single-piece acrylic IOL with a 6.0 mm round aspheric optic, and surgeries were performed by the same surgeon using the same steps and techniques. The preoperative metrics of each group were generally similar, though the PXF patients had statistically significant shallower anterior chamber depths (ACD, 3.13 vs. 3.34 mm, p<0.05) and less dilation (5.53 vs. 6.22 mm, p<0.01). There were no intraoperative complications in either group. The mean ECD in the PXF group was significantly lower than in the non-PXF group both pre- and at one and three months postoperatively; percent endothelial cell loss was 9.0% versus 3.4% in the PXF versus control groups, respectively (p=0.02) three months following surgery. Furthermore, the cell shape became more variable and the size of the endothelial cells increased postoperatively in the PXF group compared to the controls. The mean percentage increase in CCT was significantly higher in the PXF group than the control group at one month (p=0.02), though the differcontinued on page 54