To review the distribution, current trends, and resistance patterns of bacterial keratitis isolates in Toronto over the last 11 years.
Retrospective, observational, case series.
Microbiology records ...of suspected bacterial keratitis cases that underwent a diagnostic corneal scraping and cultures from January 1, 2000, through December 31, 2010, were reviewed.
Culture results and antibiotic sensitivity profiles were reviewed and analyzed.
Distribution of the main isolated pathogens as well as in vitro laboratory minimum inhibitory concentration testing results to identify resistance patterns.
A total of 1701 consecutive corneal scrapings were taken during the 11 years of the study. A pathogen was recovered in 977 samples (57.4%), with bacterial keratitis accounting for 897 of the positive cultures (91.8%). The total number of Gram-positive and Gram-negative isolates was 684 and 213, respectively. We identified a decreasing trend in Gram-positive isolates (P = 0.016). The most common isolate overall was coagulase-negative Staphylococcus (CNS) and the most common Gram-negative bacteria isolated was Pseudomonas aeruginosa. Methicillin-resistant Staphylococcus aureus (MRSA) was present in 1.3% of the S aureus isolates, whereas methicillin-resistant CNS (MRCNS) was present in 43.1% of the CNS isolates. There was a trend toward increasing laboratory resistance to methicillin from 28% during the first 4 years of the study to 38.8% for the last 3 years (P = 0.133). When analyzing the sensitivities of MRSA and MRCNS isolates to other antibiotics, there was resistance to cefazolin and sensitivity to vancomycin in all isolates, whereas resistance to other antibiotics was variable.
There was a significant decrease in the percentage of Gram-positive microorganisms over time. The sensitivity of Gram-negative isolates to tested antimicrobials was >97% response for all the reported antibiotics; this was not the case for Gram-positive isolates, in which resistance to the antibiotics was more common. Methicillin-resistant organisms accounted for 29.1% of all Gram-positive cultures in our series, suggesting that the empiric use of vancomycin in the setting of severe suspected bacterial keratitis may be justified.
Angle closure glaucoma: a mechanistic review Nongpiur, Monisha E; Ku, Judy YF; Aung, Tin
Current opinion in ophthalmology,
2011-March, 2011-Mar, 20110301, Volume:
22, Issue:
2
Journal Article
PURPOSE OF REVIEWWith recent advances in imaging techniques such as anterior segment optical coherence tomography and ultrasound biomicroscopy, there is a better understanding of nonpupil block ...mechanisms and novel risk factors contributing to the pathogenesis of angle closure glaucoma.
RECENT FINDINGSRecent studies suggest that multiple anatomical and physiological factors interplay in the pathogenesis of angle closure glaucoma. The association of greater iris convexity, area and thickness with narrow angles could result in a more anterior bowing and crowding of the peripheral iris. Other novel anatomic parameters such as greater lens vault, smaller anterior chamber width, area and volume, independently increase the risk of having angle closure. Dynamic increase or lesser reduction in iris volume during dilation supports the theory of physiological predisposition to the disease process. Choroidal expansion has been demonstrated in untreated and treated, acute and chronic primary angle closure eyes. It remains unknown whether this finding is a cause or effect in this condition.
SUMMARYWith a wider availability of imaging tools and a better understanding of risk factors and mechanisms, clinicians maybe able to more accurately identify those at greater risk of developing angle closure disease and tailor their treatment according to the predominant factor(s) involved.
Keratoconus is a form of progressive noninflammatory corneal ectasia. Although abnormalities have been documented at every level of the keratoconic cornea, the exact underlying pathophysiologic ...process remains unknown. This study aimed to determine the keratocyte density in human corneas with keratoconus imaged by laser scanning in vivo confocal microscopy.
Prospective cross-sectional study.
Thirty-six eyes of 26 subjects with keratoconus compared with 33 eyes of 33 control subjects.
Subjects were assessed via ophthalmic examination, computed topography, and laser scanning in vivo confocal microscopy.
Anterior and posterior stromal keratocyte density.
Mean age was 34.7+/-12.1 years in the control group, 38.4+/-11.0 years in the keratoconic with no contact lens wear group, and 38.5+/-10.3 years in the keratoconic with contact lens wear group. No significant difference was noted in age or gender between the groups. Mean keratocyte density in the control group was 786+/-244 cells/mm(2) in the anterior stroma and 293+/-35 cells/mm(2) in the posterior stroma. Anterior keratocyte density was higher than posterior keratocyte density (P<0.001). Anterior keratocyte density was significantly lower in contact lens-wearing keratoconic subjects in comparison with controls (463 vs. 786 cells/mm(2); P<0.001). Posterior keratocyte density was significantly lower in keratoconic subjects with no contact lens wear (236 vs. 293 cells/mm(2); P<0.001) and in keratoconic subjects with contact lens wear (208 vs. 293 cells/mm(2); P<0.001). In subjects with keratoconus, anterior keratocyte density correlated with central corneal thickness (r = 0.426, P = 0.012) and inversely with steepest keratometry values (r = -0.383, P = 0.028).
Keratocyte density is significantly lower in subjects with keratoconus, and the decline in keratocyte density correlates with indices of disease severity. In vivo confocal microscopy offers the opportunity to study early microstructural changes in the keratoconic cornea.
PURPOSE:To report the outcome and the reversibility of refractive outcomes after intrastromal corneal ring segment (ICRS) explantation in patients with keratoconus treated with ICRS implantation and ...same-day collagen crosslinking (CXL).
METHODS:This is a retrospective review of ICRS explantation in 3 eyes of 3 patients with keratoconus that had undergone femtosecond laser–enabled placement of paired ICRS (Intacs) with same-day CXL by a single surgeon between 2008 and 2011. The main outcome measures included baseline/preexplantation/postexplantation visual acuity, refractive error, keratometry, and higher order aberrations.
RESULTS:None of the patients lost best-corrected distance visual acuity lines. ICRS can be safely and easily explanted from keratoconic eyes with previous CXL. Some of the topographic benefits gained from ICRS implantation may persist after explantation.
CONCLUSIONS:Despite the reversal of refractive outcomes, the preservation of topographic changes may occur in some cases after the explantation of 1 or both the segments in patients with keratoconus treated with ICRS implantation with same-day CXL.
To evaluate the efficacy of single or paired intrastromal corneal ring segments (ICRS) combined with ultraviolet-A and riboflavin collagen crosslinking (CXL) in patients with keratoconus.
Cornea ...Unit, Toronto Western Hospital, Toronto, Ontario, Canada.
Retrospective comparative case series.
Consecutive patients with keratoconus had femtosecond laser-assisted ICRS implantation combined with same-day CXL between 2008 and 2011. The main outcome measures included improvement in visual acuity, subjective refractive error, keratometry values, and total higher-order aberration (HOA).
Eighty-five eyes of 74 patients with keratoconus (paired ICRS: 47 eyes of 40 patients; single ICRS: 38 eyes of 34 patients) were included in the study. The uncorrected distance visual acuity was significantly improved after single ICRS (3.4 lines; P=.04) and paired ICRS (2.7 lines; P=.01) implantation combined with CXL, while corrected distance visual acuity (CDVA) remained stable. The single and paired ICRS groups had a significant reduction in mean cylinder at 1 year (single ICRS: -3.84 diopters D ± 1.72 SD versus -2.19 ± 1.54 D, P=.02; paired ICRS: -3.91 ± 1.45 D versus -2.96 ± 1.92 D) (P=.02). There was no significant difference in total HOAs. Single ICRS implantation and paired ICRS implantation with CXL were equivalent in all refractive parameters. No patient lost lines of CDVA.
As determined by corneal topography, implantation of single or paired ICRS combined with same-day CXL was safe and effective in patients with keratoconus.
To evaluate the efficacy of phototherapeutic keratectomy (PTK) combined with implantation of a single inferior intrastromal corneal ring segment (ICRS) and riboflavin with ultraviolet-A collagen ...crosslinking (CXL) performed sequentially on the same day in the management of keratoconus.
Cornea Unit, Toronto Western Hospital, Toronto, Ontario, Canada.
Case series.
This retrospective review comprised consecutive patients with progressive keratoconus having transepithelial PTK followed by femtosecond laser-enabled placement of a single inferior ICRS and CXL on the same day by the same surgeon between December 2010 and August 2011. The main outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), mean refraction spherical equivalent, keratometry (K), and total higher-order aberrations.
Sixteen eyes of 13 patients were included in the study. Six months after same-day PTK combined with implantation of a single inferior ICRS and CXL, there was a significant improvement in UDVA, CDVA, and the mean and steep K values. No patient lost CDVA lines.
Phototherapeutic keratectomy combined with implantation of a single inferior ICRS and CXL on the same day was a safe, effective treatment for improving visual acuity in select patients with progressive keratoconus.
PURPOSE:To compare the outcomes of superior versus inferior conjunctival autograft (CAU) in the prevention of recurrence after performing a pterygium surgery in patients with primary pterygia.
...METHODS:This was a prospective randomized study of 60 eyes of 60 patients with primary pterygium. All the eyes underwent pterygium excision and were assigned randomly to receive either superior (30 eyes) or inferior (30 eyes) CAU. All grafts were attached with fibrin glue. The patients were followed up on postoperative day 1, day 7, 1 month, 3 months, and 6 months.
RESULTS:Outcome measures included rate of recurrence, mean surgical time, visual analog scale pain score, and amount of pain medication required in the first postoperative week. The mean surgical time, visual analog scale pain score, and amount of pain medication required in both groups were not statistically different. A follow-up of at least 6 months (mean 5.5 ± 1.1 months) was achieved in 49 eyes of 49 patients (24 eyes in the superior CAU group and 25 eyes in the inferior CAU group). One eye in the superior CAU group (4.2%) and 1 eye in the inferior CAU group (4.0%) developed pterygium recurrence. There was no statistically significant difference in the recurrence rates between the 2 groups. In the inferior CAU group, mild localized donor site scarring was noted in 2 patients (8.3%).
CONCLUSIONS:Pterygium excision with superior or inferior CAU secured with fibrin glue is safe and effective. There was no significant difference in surgical time, pain, and recurrence rates of pterygium after excision with superior or inferior CAU.
To evaluate relationships between the Disc Damage Likelihood Scale (DDLS), global and sectoral structural parameters provided by the Heidelberg Retina Tomograph (HRT), and global and regional ...functional loss in visual field (VF) testing.
Consecutive observational case series.
One hundred ten eyes from 110 patients categorized as glaucoma, glaucoma suspect, or normal.
Participants were examined clinically to grade the DDLS score and were tested with HRT and Swedish Interactive Threshold Algorithm standard 24-2 VF tests. All tests were performed within 6 months of each other by examiners masked to the other findings. For each patient, the eye with the worse mean deviation (MD) of the VF test was enrolled in the study. Each field was divided into 6 sectors based on a published scheme, and the MD for each sector was calculated. The relationships among clinical DDLS score, HRT parameters, and VF indexes were analyzed by correlation coefficients and linear regression analysis.
The relationship between the DDLS score, global and sectoral optic disc (HRT) parameters, and global and sectoral VF MDs was evaluated.
The DDLS showed significant correlation with all global and sectoral VF indexes (r = -0.39 to -0.62, all Ps < 0.0001) and with sectoral rim area HRT measurements (r = -0.27 to -0.51, all Ps < 0.006). The DDLS correlated most strongly with superior and inferior regional data from HRT and VF, and less well with temporal and nasal data. Heidelberg Retina Tomograph rim area and rim volume were the only HRT parameters to correlate moderately with global VF MD (r = 0.30, P = 0.0018, and r = 0.28, P = 0.0030, respectively). Sectoral HRT rim area correlated moderately strongly with the corresponding sectoral VF MDs in the superior and inferior sectors (r = 0.35-0.46, P = <0.0001-0.04).
Clinical disc assessment and laser tomographic data that determine the state of the neuroretinal rim are associated with sensitivity loss in VF testing in corresponding regions.
