Comparison of intraocular pressure post penetrating keratoplasty vs Descemet's stripping endothelial keratoplasty.

OBJECTIVE: To compare the effect of Descemet's stripping endothelial keratoplasty (DSEK) with penetrating keratoplasty (PKP) on intraocular pressure (IOP) and use of ocular antihypertensives. DESIGN: Retrospective cohort study. PARTICIPANTS: Thirty-five eyes in 33 patients undergoing PKP and 43 eyes in 38 patients undergoing DSEK were included in the analysis. Fifteen eyes undergoing PKP and 12 undergoing DSEK had diagnosed glaucoma. Patients undergoing corneal transplant because of trauma, keratoconus, pellucid marginal degeneration, or prior failed transplant were excluded. METHODS: Charts were obtained for all patients who underwent PKP or DSEK by a single surgeon at the Ivey Eye Institute between 2003 and 2010. IOP and all IOP-lowering medications were recorded preoperatively and at 1, 4, 8, 12, and 24 weeks postoperatively. Complications, graft survival, and glaucoma surgeries were noted. RESULTS: There was no significant difference in preoperative IOP between the 2 groups (p = 0.30). Postoperatively, IOP was significantly higher in the PKP group at 1 week (p < 0.01), 4 weeks (p < 0.01), and 8 and 12 weeks (p < 0.05), but not at 24 weeks (p = 0.62). Mean IOP increased significantly post-transplant in all groups (p < 0.05). In patients without glaucoma, postoperative IOP elevation requiring treatment occurred in 68% of PKP eyes and 23% of DSEK eyes. In patients with prior glaucoma, an increased requirement for ocular antihypertensives occurred in 60% of PKP eyes and 20% of DSEK eyes. Three trabeculectomies and 1 tube shunt were performed in the cohort with glaucoma undergoing PKP. No glaucoma surgery was required in the DSEK cohort. CONCLUSIONS: Elevation of IOP requiring treatment occurred at a lower rate after DSEK compared with PKP. This difference was significant during the early postoperative course but nonsignificant at 24 weeks. Additional long-term studies on the effect of DSEK on glaucoma and IOP control are warranted.

Primary intraocular lymphoma arising during methotrexate treatment of temporal arteritis.

CASE REPORT: Primary intraocular lymphoma arose over a period of 9 months in the left eye of an 81-year-old woman who was blind in both eyes from temporal arteritis. During this period, she was treated with prednisone and methotrexate. Following a sudden total hyphema, the eye was enucleated. Examination revealed that, in addition to iris neovascularisation and central retinal artery occlusion, the neurosensory retina was replaced by atypical lymphocytes. COMMENTS: Histological and immunohistochemical studies confirmed the presence of a lymphoma with features indicative of an immunosuppression-related disorder. The relationship of the lymphoma to the vascular changes within the eye is discussed.

Are subjects satisfied with the informed consent process? A survey of research participants.

OBJECTIVE: Letters of information (LOI) for clinical trials are becoming longer and more complicated. We investigated patients' perspectives of their ability to understand the information presented during a clinical trial. Satisfaction with and motivation for participation in clinical trials were also ascertained. Perceptions from various treatment disciplines were compared. METHODS: Participants were chosen from 14 clinical trials (departments of rheumatology, ophthalmology, and cardiology) conducted at the same university. Subjects were asked to complete a written questionnaire that assessed demographic information, recall and understanding of information, subjects' decisions to participate, and perceptions/opinions of the study. The response rate was 75% (rheumatology, n = 74; ophthalmology, n = 32; cardiology, n = 84). RESULTS: The majority of respondents (98%) indicated that they were satisfied with the informed consent process and with their involvement in a trial (97%). Subjects who reported having understood the LOI had better recall of placebo/active drug comparator (p < 0.03), and better understanding of why placebo was used (p < 0.04). No differences were found between those who reported understanding and those who did not on understanding the concept of concealed allocation (blinding). Subjects who felt they had received "the right amount of information" were more likely not to understand concealed allocation. The most frequent reason for trial participation was to help medical science (80%). Subjects with higher education were more likely to understand the reason for placebo use (p < 0.0003), but were not more likely to understand concealed allocation (p < 0.08). CONCLUSION: Subjects reported that they were satisfied with the informed consent process and their experience in a clinical trial, and that they understood trial concepts. Subjects may be able to self-assess their own level of understanding for trial concepts that intrinsically make sense within the context of their beliefs about medical care, but other trial concepts may be misunderstood/misinterpreted regardless of self-assessment of understanding or education level (i.e., concealed allocation). Subjects may prefer to believe that investigators know which treatment they are receiving, and have made a good treatment decision specific to their case, despite having being told about concealed allocation and placebo use.