Douglas J. Covert

Visual acuity, refractive error, and endothelial cell density six months after Descemet stripping and automated endothelial keratoplasty (DSAEK).

Purpose: To evaluate visual acuity, refractive outcomes, and endothelial cell density 6 months after Descemet stripping and automated endothelial keratoplasty (DSAEK). Methods: We performed an institutional review board-approved prospective study of a surgical case series of 34 patients at 2 institutions undergoing DSAEK for Fuchs endothelial dystrophy, pseudophakic bullous keratopathy, or aphakic bullous keratopathy with or without simultaneous phacoemulsification and intraocular lens implantation. Clinical outcomes, including best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction, and refractive astigmatism and topographic or keratometric astigmatism, were assessed at the 6-month postoperative examination and compared with preoperative values with paired Student t tests. The change in endothelial cell density from the eye bank examination to 6 months after transplantation was similarly evaluated. Results: BSCVA averaged 20/99 preoperatively and 20/42 postoperatively (P < 0.0001). After DSAEK, 30 (88.2%) of 34 patients showed improved BSCVA, and 21 (61.8%) of the 34 patients achieved a BSCVA of 20/40 or better. For patients not undergoing simultaneous phacoemulsification and intraocular lens implantation, a hyperopic shift in refraction of 1.19 ± 1.32 D was noted. Refractive astigmatism, topographic astigmatism, and keratometry showed no statistically significant change. Endothelial cell density of donor corneas averaged 2826 ± 370 cells/mm2, whereas the mean postoperative density was 1396 ± 440 cells/mm2. This finding corresponded to an average loss of 1426 cells/mm2 (50% loss; P = 0.0001). The first half of cases experienced an average cell loss of 1674 cells/mm2 (59% loss) compared with 1181 (41% loss) in the second half of cases (P = 0.005). Three (9%) of 34 grafts experienced iatrogenic graft failure and required reoperation with new donor tissue. Also, 9 (27%) of 34 grafts experienced dislocation in the early postoperative period and required repositioning. Conclusions: In this prospective study of DSAEK for bullous keratopathy and Fuchs endothelial corneal dystrophy, improvement of visual acuity was achieved with only a mild tendency toward hyperopic shift and without significant induced astigmatism. Endothelial cell loss was significant, however, and may be related to surgical experience.

Short-term intraocular pressure changes immediately after intravitreal injections of anti-vascular endothelial growth factor agents.

PURPOSE To assess short-term trends and the need to monitor intraocular pressure (IOP) changes immediately after intravitreal injections of ranibizumab, bevacizumab, pegaptanib, and triamcinolone acetonide. DESIGN Retrospective, interventional case series. METHODS Charts of 213 consecutive injections to 120 eyes of 112 patients were reviewed. Pressures were measured before injection, immediately after injection (T0), and at five-minute intervals until IOP was less than 30 mm Hg. Optic nerve perfusion was assessed by testing for hand movement vision and by indirect ophthalmoscopic examination. Kaplan-Meier and Chi-square analyses of IOP after injections and correlation of IOP spikes to drug, needle bore size, injection volume, and history of glaucoma were performed. RESULTS Mean preinjection IOP was 14 mm Hg (range, 7 to 22 mm Hg). Mean IOP at T0 was 44 mm Hg (range, 4 to 87 mm Hg). All but one eye had at least hand movement vision and a perfused optic nerve at T0. IOP was reduced to less than 30 mm Hg in 96% of injections by 15 minutes and in 100% by 30 minutes. Eyes with a history of glaucoma took longer to normalize the IOP (P = .002). Statistically significant IOP spikes were observed with a smaller needle bore size (P < .0001) and in eyes with a history of glaucoma (P = .001). CONCLUSIONS Elevations in IOP immediately after intravitreal injections are common, but are transient. Prolonged monitoring of IOP may not be necessary on the day of injection in most cases if hand movement vision, optic nerve perfusion, and lack of intraocular complications have been verified. However, cautious monitoring should be considered in select cases.

Descemet stripping and automated endothelial keratoplasty (DSAEK) in eyes with failed penetrating keratoplasty.

Purpose: To report our results of using Descemet stripping and automated endothelial keratoplasty (DSAEK) in eyes with failed penetrating keratoplasty (PK). Methods: An institutional review board-approved, prospective, surgical case series of 7 eyes of 7 consecutive patients undergoing DSAEK for graft failure after 1 or more PKs at 1 academic eye center. Results: The mean follow-up period was 13.3 months (range, 9-18 months). One eye suffered recurrent donor graft dislocation and elected to undergo repeat PK instead of repeat DSAEK. Of the remaining 6 patients, the average preoperative visual acuity (VA) was 20/851 compared with a best-corrected visual acuity (BCVA) of 20/65 postoperatively (P = 0.008). After DSAEK, 6 (100%) eyes showed improved BCVA, and 4 of 6 eyes (67%) achieved a BCVA of 20/40 or better. All 6 grafts remained clear at the last follow-up visit. Two eyes showed graft dislocation on the first postoperative day and underwent repositioning of the lenticule with good results. Two other eyes were diagnosed with primary iatrogenic graft failure within 1 week of DSAEK and underwent repeat DSAEK with new donor tissue with good results. One eye experienced acute graft rejection that was successfully treated with topical steroids. Conclusions: This pilot series of DSAEK in eyes with graft failure from previous PK shows favorable VA and graft clarity outcomes. The complications observed were similar to those observed for DSAEK for Fuchs dystrophy and pseudophakic bullous keratopathy and include graft dislocation, iatrogenic graft failure, and homograft rejection.

Candida keratitis after descemet stripping and automated endothelial keratoplasty.

Purpose: To report the donor-to-host transmission of Candida albicans after Descemet stripping and automated endothelial keratoplasty (DSAEK). Methods: An 80-year-old woman with pseudophakic bullous keratopathy developed an infiltrate in the donor corneal lenticule after DSAEK. Results: Donor corneoscleral rim cultures grew C. albicans. Gram stain of the removed corneal lenticule demonstrated budding yeast and pseudohyphae, and cultures yielded C. albicans. Despite topical and systemic antifungal therapy and therapeutic penetrating keratoplasty, the patient developed a blind painful eye and underwent enucleation. Conclusions: This case report indicates that fungal keratitis may occur from donor-to-host transmission after DSAEK. The location of the infected tissue poses diagnostic and therapeutic challenges for the surgeon.

Epithelial ingrowth after Descemet-stripping automated endothelial keratoplasty.

PURPOSE To report the diagnosis and treatment of a patient who developed epithelial ingrowth after Descemet-stripping automated endothelial keratoplasty (DSAEK). METHODS We describe the case of an 80-year-old woman who underwent DSAEK for pseudophakic bullous keratopathy. After surgery, the patient underwent 2 additional rebubbling procedures for recurrent donor lenticule dislocation. She was subsequently found to have an enlarging interface epithelial ingrowth that led to graft failure. RESULTS After donor lenticule exchange, mechanical scraping, and irrigation-aspiration of residual epithelial cells, there was no evidence of the histologically confirmed epithelial ingrowth during a 2-year follow-up interval. CONCLUSIONS This 1 case report suggests that epithelial ingrowth may occur after DSAEK. This case was successfully treated surgically.Objective:There is considerable evidence that patients with HIV fare better in hospitals that treat more HIV-positive patients. Yet, it is possible that much of this benefit is attributable to the care provided by physicians who treat high volumes of HIV-positive patients. This study examines the relation between 2 measures of volume (the number of HIV-positive patients treated in a hospital and the number of HIV-positive patients treated by the attending physician) and the probability of dying in the hospital. Data:This study uses discharge data from 43,325 patients hospitalized with HIV disease in 5 states (Colorado, Maryland, New Jersey, New York, and Washington State) in 2002. These data were obtained from the Agency for Healthcare Research and Qualitys Healthcare Cost and Utilization Project State Inpatient Databases. Study Design:Volume-outcome studies have demonstrated an inverse relation between the number of HIV-positive patients treated at a hospital and the mortality rate for these patients. Yet, the most current of these studies is based on data more than a decade old, and none of these account for the volume of HIV-positive patients treated by the physician. This study uses multivariate logistic regression analyses to estimate the impact of hospital and physician volume on patient mortality. Results:This study found that when measures of physician and hospital volume are included in a regression equation explaining patient mortality, only the variable measuring physician volume remains statistically significant. Moreover, when a variable is defined for each patient based on the quartile rankings of the patients hospital volume and the patients physician volume, the quartile ranking of physician volume is a better predictor of survival than the quartile ranking of hospital volume. Conclusion:These findings suggest that the volume of patients treated by the attending physician is the key measure of volume associated with the survival of hospitalized HIV-positive patients.

Microbiological spectrum of organisms isolated from explanted scleral buckles.

Scleral buckle removal is an uncommon procedure performed for various reasons. Microbiological information on explanted scleral buckles remains limited. The authors identified 37 cases of scleral buckle removal during an 18-year period. Bacterial cultures isolated an organism in 4 of 9 patients (44%) with clinical infection. Organisms identified included methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Mycobacterium abscessus, and coagulase-negative Staphylococcus species. Bacterial cultures isolated an organism in 3 of 11 patients (27%) without clinical infection. Organisms identified included Nocardia species, Alcaligenes xylosoxidans, and Mycobacterium chelonae. Scleral buckles appearing clinically infected may be associated with more virulent organisms and a greater chance of identifying an organism. Bacterial cultures may be of value for scleral buckles upon removal.

Quantitative assessment of the 103-hexagon multifocal electroretinogram in detection of hydroxychloroquine retinal toxicity

Purpose To evaluate the utility of ring ratios in detecting hydroxychloroquine (HCQ) related retinal toxicity using the 103-hexagon multifocal electroretinogram (mfERG). Design Retrospective cross-sectional study. Methods 23 patients taking HCQ were consecutively evaluated for retinal toxicity and divided into those without (HCQ-non-toxic group) and with documented visual field loss (HCQ-toxic group). A control patient group without retinal disease and not on HCQ was used for comparison. 103-hexagon P1 mfERG amplitude response densities were analysed by averaging the 103 responses into six (age-corrected) concentric rings (R1–R6), calculating standard ring ratios (R1:R2–R1:R6) and R5 ring ratios (R5:R1–R5:R6). Receiver operating characteristic curves were used to compare these tests for detecting toxicity. Results Relative to HCQ-non-toxic and control groups, the HCQ-toxic group showed generalised reduction of the 103-hexagon mfERG absolute responses most prominent in the foveal/pericentral regions. R5 ring ratios were superior to standard ring ratios in discriminating the HCQ-toxic from the HCQ-non-toxic and control groups and were approximately equivalent to pericentral absolute ring responses in detecting HCQ retinal toxicity by receiver operating characteristic criteria, with R5:R4 and R5:R3 ratios performing best. However, R5 ring ratios revealed improved sensitivity over absolute ring responses (89% vs 73%) at a 95% specificity threshold. Conclusions Ring ratio analysis using the R5 ring response as the ‘internal reference ring’ appeared equivalent to pericentral absolute ring responses in detecting HCQ retinal toxicity, and possibly superior at clinically desirable specificity thresholds. R5 ring ratios did not require age correction, a potential clinical advantage over absolute ring responses.

Accuracy of surrogate decision making in elective surgery

PURPOSE: To assess the accuracy of surrogate decision making for elective cataract surgery. SETTING: Comprehensive Ophthalmology Department of Tertiary Care Hospital. METHODS: Decisions regarding elective cataract surgery of currently competent, elderly patients were compared with the predictions of patient‐identified surrogate decision makers in scenarios of current state of mental health and progressive dementia. Patients were identified (age >50 years, Mini‐Mental Status Score >20, absence of significant noncataract pathology) consecutively at a scheduled clinic visit to a single provider. Preferences for cataract surgery in the current state of health and hypothetical progressive dementia were assessed on a Likert scale. The same interviewer contacted patient‐identified surrogate decision makers within 48 hours. Independently, a survey of community ophthalmologists was performed. The concordance of surrogate predictions with patient preferences (32 pairs) was assessed using percentage agreement, the κ coefficient with dichotomous Likert scale data, and chi‐square analyses (concordance beyond chance). RESULTS: In their current state of health, most patients said they would prefer to have surgery if they were deemed to have a visually significant cataract, which was accurately predicted by surrogates (72% agreement, κ = 0.65, chi square = 16.5). In a hypothetical dementia scenario, contrary to perceptions of patients and their surrogates, proxies were unable to accurately represent a patients wishes for elective cataract surgery (34% agreement, κ = 0.23, chi square = 14.4). Physicians tended to withhold intervention in the dementia scenario. CONCLUSIONS: The findings suggest that current methods of decision making in elective surgery for patients unable to make autonomous decisions may be seriously flawed. This extends previous findings of inaccuracy with the substituted judgment approach to end‐of‐life issues to reflect elective surgical scenarios.

Scleral buckle removal in the vitrectomy era: a 20-year clinical experience.

Purpose: To describe the effect of scleral buckle (SB) removal on preoperative symptoms and signs prompting removal and to assess the risk of recurrent retinal detachment (RD) after SB removal. Methods: A retrospective study of 36 patients who underwent SB removal between August 1988 and December 2007 was performed. Indications for SB removal, presence or absence of pain or diplopia, and recurrence of RD were recorded. Composite RD rates were estimated from previously published studies and stratified into those occurring during the previtrectomy era versus later (1980 to present). Results: Mean follow-up time was 75.5 months after SB removal. Thirty-two of 33 patients (97%) who had preoperative pain had symptom relief. Twelve of 12 patients who had clinical infection had resolution. Of the four patients with diplopia, two experienced complete resolution and two reported substantial improvement but required prisms to obtain single vision. Four of 34 patients (12%) whose retinas were attached at the time of SB removal developed recurrent RD but were successfully repaired without significant visual loss from the RD. Conclusion: Scleral buckle removal is effective in eliminating SB-related pain and infection. Symptomatic diplopia can sometimes improve after SB removal. The rates of RD after SB removal observed in this study (12%) and in others performed in the era of vitrectomy were notably lower than those of previous reports.

The Use of Best Visual Acuity over Several Encounters as an Outcome Variable: An Analysis of Systematic Bias

PURPOSE To investigate whether the use of the best of multiple measures of visual acuity as an endpoint introduces bias into study results. METHODS Mathematical models and Monte Carlo simulations were used. A model was designed in which a hypothetical intervention did not influence the visual acuity. The best of one or more postintervention measures was used as the outcome variable and was compared to the baseline measure. Random test-retest variability was included in the model. RESULTS When the better of two postintervention measures was used as the outcome variable with a sample size of 25, the model falsely rejected the null hypothesis 55% of the time. When the best of three measures was used, the false-positive rate increased to 90%. The probability of falsely rejecting the null hypothesis increased with increasing sample size, also increasing the number of measures used to select the outcome variable. CONCLUSIONS Using the best of multiple measures as an outcome variable introduces a systematic bias resulting in false conclusions of improvement in that variable. The use of best of multiple measures of visual acuity as an outcome variable should be avoided.