In a prospective, interventional case series, researchers have shown that the combination of bevacizumab and dexamethasone in patients with retinal vein occlusion increases visual acuity and prolongs the time between injections compared with either of these medications alone.
Patients diagnosed with RVO seen between September 2009 and July 2010 were included in this study if they had received previous anti-VEGF therapy. Patients were included in analysis if the previous anti-VEGF therapy was at least six weeks before, as long as their optical coherence tomography showed signs of edema defined as >300 on spectral-domain OCT. Exclusion criteria included history of vitrectomy and/or rubeotic or advanced glaucoma. All patients were evaluated with Snellen visual acuity and measured for macular thickness and intraocular pressure. At baseline, all patients were injected with bevacizumab, followed by dexamethasone intravitreal implant two weeks later. These patients were reexamined on a monthly basis and treated when edema occurred.
Thirty-four eyes of 33 patients, with a mean age of 72.8 years, were identified. Thirty-five percent were diagnosed with central RVO, while the other 65 percent had branch RVO. Of treated patients, 97 percent gained vision during the study. Macular thickness decreased with the combination treatment; the effect continued an average of 26 days from the initial bevacizumab treatment. Retreatment was unnecessary in 18 percent of the population during the six-month study period.
Singer M, Bell D, Woods P, Pollard J, et al.
Comparison of ACD Using Four Devices
In a comparative case series, doctors evaluated the congruity of anterior chamber depth measurements in one eye of 42 healthy participants using three-dimensional corneal and anterior segment OCT, partial coherence interferometry, Scheimpflug imaging and ultrasound biomicroscopy. The ACD measurements were significantly different between the devices and not interchangeable, except for PCI true and CAS-OCT auto, and CAS-OCT auto and CAS-OCT manual.
The differences between the measurements were evaluated by two-way analysis of variance and post hoc analysis, and agreement between the measurements was evaluated using Bland-Altman analysis. To evaluate true ACD using PCI, the automatically calculated ACD minus the central corneal thickness measured by CAS-OCT was defined as PCI true. Two ACD measurements were also taken with CAS-OCT.
The mean ACD was 3.72 mm ±0.23 (PCI), 3.18 ±0.23 mm (PCI true), 3.24 ±0.25 mm (Scheimpflug), 3.03 ±0.25 mm (UBM), 3.14 ± 0.24 mm (CAS-OCT auto) and 3.12 ±0.24 mm (CAS-OCT manual). A significant difference was observed between PCI biometry, Scheimpflug imaging and the other methods. Post hoc analysis showed no significant differences between PCI true and CAS-OCT auto or between CAS-OCT auto and CAS-OCT manual. Strong correlations were observed between all measurements; however, Bland-Altman analysis showed good agreement only between PCI true and Scheimpflug imaging and between CAS-OCT auto and CAS-OCT manual.
Nakakura S, Mori E, Nagatomi N, Tabuchi H, Kiuchi Y.
How Specialists Manage Chronic Herpes Zoster Ophthalmicus
In November 2010, a survey of 15 questions was distributed to the Cornea Society listserv. Questions identified respondents’ treatment practices for recurrent herpes zoster ophthalmicus and opinions regarding prolonged antiviral prophylaxis and zoster vaccine. Responses indicate many cornea specialists are managing recurrent or chronic cases of HZO, but there is variability in the use of topical corticosteroids and antivirals. Additionally, no consensus exists on the efficacy of prolonged antiviral therapy or the adult zoster vaccine to reduce chronic or recurrent disease.
Of 100 respondents, the majority were cornea specialists (83 of 98, 85 percent). Eighty-seven percent reported treating recurrent or chronic cases of HZO in the last year. The most common choice of treatment in the posed recurrent HZO clinical scenario was a combination of oral antiviral and topical corticosteroid, although significant variability existed in the duration of oral antiviral administration. Fifty-four respondents believed that prolonged acyclovir prophylaxis could reduce recurrent signs of HZO; 28 percent believed that recurrences of HZO could be reduced after the period of acyclovir administration. For patients with a history of HZO, 64 percent of respondents reported not recommending the adult zoster vaccine, but 46 percent believed that the vaccine could reduce recurrent signs or did not know.
Sy A, McLeod S, Cohen E, Margolis T, et al.
Posterior Corneal Surface Altered Post-LASIK
Researchers from the Cole Eye Institute evaluated the posterior corneal surface response of 80 eyes at a very early stage after myopic LASIK with different ablation depths, observing posterior steepening and a shift toward prolateness of the posterior surface, with a tendency to return toward the preoperative level between one and three months. The degree of change was related to the amount of anterior tissue severed.
Healthy myopic eyes were divided based on the achieved ablation depth as follows: Group 1, more than 100 µm; Group 2, between 50 µm and 99 µm; Group 3, less than 50 µm. Posterior eccentricity and central (0 to 4 mm), paracentral (4 to 7 mm) and peripheral (7 to 10 mm) posterior corneal curvatures were measured with the Galilei system preoperatively and postoperatively after one day, one week and one and three months.
Posterior surface steepening and a shift toward prolateness occurred in all groups, with a peak within the first week before returning toward the original level after one month. The maximum change in the central posterior cornea occurred after one day in Group 1 and reached -0.106 D. This change was statistically significant (p=0.03) and statistically greater than the change in Group 2 (mean -0.042 D; p=0.02) and Group 3 (mean -0.026 D; p<0.01). This change was not significant after three months.
Smadja D, Santhiago M, Mello G, Roberts C, et al.
Pilot Study for Detection of Wet AMD with OCT
In this prospective, observational, nonrandomized study, 79 patients diagnosed with nonexudative macular degeneration in one eye and exudative macular degeneration in its fellow underwent examination followed by OCT in the study eye (nonexudative macular degeneration eye) every three months for two years. Of the 15 patients who developed exudative macular degeneration, 13 had disease progression identified on OCT before examination and/or fluorescein angiography showed changes.
Patient examination included visual acuity, intraocular pressure, biomicroscopy and ophthalmoscopy followed by OCT. If the examination did not show choroidal neovascularization, but OCT images raised suspicion, patients were re-examined in four to six weeks and/or fluorescein angiography was performed. Visual acuity, OCT anomaly detection and time between OCT and fluorescein angiography detection were examined.
Fifteen patients (19 percent) developed exudative macular degeneration, as confirmed by fluorescein angiography, in the study eye. Four additional patients showed potential exudative macular degeneration on OCT only. Subretinal pigment epithelium fluid was the most common OCT anomaly, with development of sub-/intraretinal fluid also visible.
Padnick-Silver L, Weinberg A, LaFrano F, Macsai M.
Contact Lenses Affect Corneal Biomechanical Parameters
Results from research out of Turkey suggest that ocular response analyzer-generated parameters may be different in subjects with and without contact lens usage. The study consisted of 56 myopic patients who used contact lenses (study group) and 123 myopic patients who did not. Intraocular pressure was measured with an ORA and a Goldmann applanation tonometer. Central corneal thickness was measured with an ultrasonic pachymeter. Axial length and anterior chamber depth measurements were acquired with contact ultrasound A-scan biometry. The differences in ORA parameters between study and control group participants were analyzed.
The mean corneal hysteresis in study and control groups was 10.1 ±1.6 mmHg (6.5 to 15.9 mmHg) and 9.7 ±1.5 mmHg (6.3 to 14.2 mmHg) (p=0.16). The mean corneal resistance factor was 10.4 ±1.9 mmHg (4.6 to 15.5 mmHg) in the study group compared with 9.6 ±1.9 mmHg (5.1 to 15 mmHg) in the control group. The difference in corneal resistance factor was statistically significant (p=0.014). There was no significant difference in corneal-compensated IOP (p=0.24). Mean Goldmann-correlated IOP was significantly higher in the study group than in control subjects (15.8 ±3.2 vs. 14.7 ±3.7 mmHg) (p=0.044). None of the corneal biomechanical parameters was significantly correlated to the duration of contact lens use in the study group.
Cankaya A, Beyazyildiz E, Ileri D, Ozturk F.