American Journal of Ophthalmology
American Journal of Ophthalmology
American Journal of Ophthalmology RSS feed: Current Issue. The American Journal of Ophthalmology is a peer-reviewed, scientific publication that welcomes the submission of original, previously unpublished manuscripts directed to ophthalmologists and visual science specialists describing clinical investigations, clinical observations, and clinically relevant laboratory investigations. Published monthly since 1884, the full text of the American Journal of Ophthalmology and supplementary material are also presented on the Internet at www.AJO.com . The American Journal of Ophthalmology publishes Original Articles, Brief Reports, Perspectives, Editorials, Abstracts, Correspondence, Book Reports and Announcements. Perspectives, Editorials, and Abstracts (from other journals) are published by invitation. Manuscripts are accepted with the understanding that they have not been and will not be published elsewhere substantially in any format, and that there are no ethical problems with the content or data collection. Authors may be requested to produce the data upon which the manuscript is based and to answer expeditiously any questions about the manuscript or its authors. See AJO policies on redundant publication .

  • Delayed- Versus Acute-Onset Endophthalmitis After Cataract Surgery
    Purpose: To report a large consecutive case series of patients who developed delayed-onset and acute-onset endophthalmitis after cataract surgery. Design: Retrospective consecutive case series. Methods: The current study is a retrospective consecutive case series of patients treated between January 2000 and December 2009 for culture-proven endophthalmitis after cataract surgery. The study defined 2 groups after cataract surgery: acute-onset endophthalmitis (?6 weeks after surgery) and delayed-onset endophthalmitis (>6 weeks after surgery). Results: A total of 118 patients met study criteria; cases included 26 delayed-onset cases and 92 acute-onset cases. The following clinical features and outcomes occurred in delayed- vs acute-onset cases: 1) the presenting visual acuity was ?5/200 in 31% vs 89%; 2) hypopyon was found in 46% vs 80%; 3) the most frequent isolate was Propionibacterium acnes (11/26) vs coagulase-negative Staphylococcus (57/92); and 4) patients with the most frequent isolate achieved a visual outcome of ?20/100 in 91% vs 56%. In delayed-onset cases, the intraocular lens was removed or exchanged in 19 of 26 cases (73%). Of these 19 cases, 13 achieved a visual outcome of ?20/100. Conclusions: Patients with delayed-onset endophthalmitis generally presented with better initial visual acuities, had a lower frequency of hypopyon, and had better visual outcomes compared to acute-onset patients. Propionibacterium acnes and coagulase-negative Staphylococcus species were the most common organisms cultured in delayed- and acute-onset categories, respectively, and were associated with the best visual acuity outcomes in each group.

  • Evaluation of In Vitro Efficacy of Combined Riboflavin and Ultraviolet A for Acanthamoeba Isolates
    Purpose: To evaluate in vitro the amoebicidal effects of riboflavin and ultraviolet A (UVA) collagen cross-linking. Design: Experimental study, laboratory investigation. Methods: Two different strains of Acanthamoeba species were tested identically. Four treatment groups were considered: group 1 consisted of 0.1% riboflavin and 30-minute UVA irradiation; group 2 consisted of 0.1% riboflavin and 60-minute UVA irradiation; group 3 consisted of no riboflavin and no UVA exposure; group 4 consisted of 0.1% riboflavin and no UVA exposure. The application of UVA was performed under the parameters used for in vivo corneal collagen cross-linking. Results: In all cases, cysts and trophozoites were detected 24 hours after treatment at a radial distance from the center of the seeding point more than 5 mm, indicating that the amoebae were viable. All treated and untreated groups of amoebae from the 2 strains exhibited growth (radii of 14 to 15 mm in groups 1, 3, and 4; radius of 12 mm in group 2). The final morphologic features of the 2 strains of trophozoites that received treatment were similar to those of the initial seeding group and the untreated control group. Conclusions: The results obtained in our study show that a single dose (30 or 60 minutes) of cross-linking cannot achieve eradication in the 2 different Acanthamoeba strains examined. However, in vitro results do not always indicate in vivo efficacy, so future studies should test the validity of this treatment for Acanthamoeba keratitis.

  • Full-Cycle Steam Sterilization in Ophthalmic Surgery?The Effect of Wrapping Instruments
    Purpose: To determine if wrapping instruments in conjunction with full-cycle steam sterilization affects the incidence of postoperative infection in patients undergoing ophthalmic surgery in a dedicated eye center. Design: Retrospective, consecutive-case, comparative study. Methods: Two consecutive groups, each of approximately 19 000 ophthalmic surgical patients, were reviewed for postoperative infection. For both groups, the surgical instruments were sterilized using full-cycle, steam sterilization, with a single major difference. The instruments for the first group were sterilized with equipment located adjacent to the operating room and no wrapping of the instruments was used, whereas for the second group, the sterilization equipment was located at a central facility and the instruments were wrapped before being transported to the operating rooms. Results: In the unwrapped sterilization group 17 presumed postoperative infections were identified, compared to 9 presumed infections in the wrapped sterilization group. Because the observed infection rates for each group were so low, this apparent difference is not statistically significant (P = .16). Similarly, differences found in the incidence of culture-positive cases of endophthalmitis (5 for unwrapped vs 3 for wrapped) were not statistically significant (P = .47). Conclusions: In a dedicated, high-volume eye facility, the incidence of presumed postoperative infection associated with unwrapped and wrapped full-cycle steam sterilization were shown to be identical within statistical error. This provides strong evidence that if eye surgical facilities carefully clean surgical instruments and follow the industry and manufacturer guidelines, they can, with confidence, use either of these 2 methods of sterilization. This study presents the first concrete data that corroborate the current position of The Joint Commission, American Academy of Ophthalmology (AAO) and American Society of Cataract and Refractive Surgery (ASCRS).

  • Comparison of Intraocular Pressure Measurement Using 4 Different Instruments Following Penetrating Keratoplasty
    Purpose: To compare intraocular pressure (IOP) measurements after penetrating keratoplasty (PK) using Goldmann applanation tonometry (GAT; Haag-Streit USA), TonoPen XL (Reichert Inc), Pascal Dynamic Contour tonometer (PDCT; Swiss Microtechnology AG), and Ocular Response Analyzer (ORA; Reichert Inc) and to analyze effects and correlation of corneal thickness and curvature on these measurements. Design: Prospective, cross-sectional study. Methods: settings: Departments of Ophthalmology, University of Auckland and Auckland District Health Board, New Zealand. study population: Thirty-one eyes of 31 participants with previous PK. observations: IOP measured using GAT, TonoPen, PDCT, and ORA. Central corneal thickness (CCT) and corneal astigmatism were assessed by Pentacam rotating Scheimpflug tomography. main outcome measure: Degree of agreement in IOP measures and correlation with CCT and corneal astigmatism. Results: Mean age was 44.5 ± 21.0 years and mean time since PK was 27.7 ± 28.2 months (range 3.0?122.4 months). Mean CCT was 585 ± 149 ?m and mean corneal astigmatism 5.5 ± 3.8 diopters. There was no significant difference in IOP measured by GAT and TonoPen; however, both PDCT (2.12 mm Hg, P < .01) and ORA (6.29 mm Hg, P < .01) measured significantly higher IOPs compared to GAT. ORA showed the least agreement with GAT. Significant correlation was identified between each pair of measurement techniques. No instruments correlated significantly with CCT. Only PDCT showed no significant correlation with corneal astigmatism. However, no IOP measures correlated with corneal astigmatism if sutures in situ or less than 1 year post-PK. Conclusions: TonoPen or PDCT are the most suitable alternatives for measuring IOP in PK eyes where GAT readings are difficult to obtain. PDCT also offers the advantage of being independent of both CCT and corneal astigmatism.

  • Association Between Corneal Biomechanical Properties and Glaucoma Severity
    Purpose: To investigate the association between corneal biomechanical parameters using the Ocular Response Analyzer (ORA) and glaucoma severity. Design: Observational cross-sectional study. Methods: Two hundred ninety-nine eyes of 191 patients with confirmed or suspect glaucoma were recruited at the University of California, San Diego. Corneal hysteresis (CH) and corneal resistance factor (CRF) were obtained from all participants. Standard automated perimetry was done using the 24-2 Swedish Interactive Threshold Algorithm. Retinal nerve fiber layer (RNFL) thickness measurements were obtained using GDx ECC and spectral-domain optical coherence tomography (SD-OCT). The association between ORA parameters and disease severity was evaluated using univariable and multivariable regression models. Results: CH and CRF were both positively associated with mean defect (MD) (R2 = 0.03; P < .01 and R2 = 0.10; P < .01, respectively). In multivariable analysis, the association between CRF and MD remained significant while CH to MD did not (P < .01 and P = .77). In the GDx ECC subgroup (204 eyes), there was a weak association between CH and CRF and average RNFL thickness (R2 = 0.07; P < .01 and R2 = 0.05; P < .01, respectively), which was not observed in the SD-OCT subgroup (146 eyes) (R2 = 0.01; P = .30 and R2 = 0.01; P = .21). After adjusting for central corneal thickness, age, and axial length, the relationship of CH and CRF to RNFL thickness no longer reached statistical significance. Conclusions: The current study found only a weak relationship between corneal biomechanical parameters and measures of structural and functional damage in glaucoma.