While retinal thickness can be used for detecting glaucoma in older patients, the annulus and foveal pit might be more accurate, according to a recent study.
Since most current data on RT and its connection to glaucoma were collected from younger individuals, the authors conducted a study to find the correlation between RT in older individuals and glaucoma. One hundred and three eyes of 62 individuals underwent visual field testing and a comprehensive eye examination by a glaucoma specialist. RT was measured with the retinal thickness analyzer and RT values in specific regions were derived using a custom-designed MatLab program. Mean age was 61 years.
Sixty-six percent were female and 82 percent were of European descent.
Results showed that average macula thinned out with age. The average mean deviation on visual field testing was 0.03 dB and the average pattern SD was 1.51 dB. The mean RT of the entire macula was 159 ±16 µm, and proved to be the lowest in the foveal pit and highest in the parafoveal annulus. The average distance from the foveal pit to the thickest point in the parafoveal annulus was 1,240 ±138 µm.
The mean RT of the entire macula was slightly less in older individuals (slope=-5.7 µm/10 y, p=0.02) but the height of the pa-rafoveal annulus relative to the foveal pit—which is determined by the combined thickness of the parafoveal nerve fibers, ganglion cells, inner plexiform layer and inner nuclear layer—did not vary with age (p=0.62). That lack of variation indicates that the height of the parafoveal annulus relative to the foveal pit may be a better marker of neuronal tissue health than the average RT of the entire macula.
(J Glaucoma 2009;18:37-43)
Jampel H, Vitale S, Ding Y, Knezevich F, et al.
Patients Won't Lose Sleep Over Blue-light-blocking IOLs
Blue-light-blocking IOLs do not affect a patient's quality of sleep, according to a recent Australian study. The research focused on 49 patients who had bilateral cataract surgery during the preceding 12 months with implantation of a conventional SI40NB IOL or an AcrySof Natural SN60WF blue-light-blocking IOL. Of the 49 patients, 31 received conventional IOLs and 18 received blue-light-blocking IOLs.
At least six months after second-eye surgery, patients were contacted by telephone and given the Pittsburgh Sleep Quality Index questionnaire. Results were compared between groups.
The mean age of the patients was 80 years ±8.1 (SD). The median PSQI score was six (interquartile range three to eight). There were no statistically significant differences in PSQI scores between the two IOL groups (p=0.65), despite adjustment for sex, age, medication and time since surgery.
Results showed that the blue-light-blocking IOLs had no effect on a patient's quality of sleep, also indicating that these IOLs might serve as an alternative to conventional IOLs without having a detrimental effect on circadian rhythm.
(J Cataract Refract Surg 2009;35:83-8)
Landers JA, Tamblyn D, Perriam D.
Is Repeat 360-degree SLT Safe?
Findings from a recent study suggest that repeat 360-degree selective laser trabeculoplasty may be safe and effective after an initially successful 360-degree SLT has failed.
The study looked at 44 eyes of 35 patients ages 18 and older with open-angle glaucoma (primary open-angle, pseudoexfoliation or pigmentary glaucoma) uncontrolled on maximum tolerable medical therapy. The pa-tients underwent an initial 360-degree SLT (SLT1), which was successful for at least six months, but eventually lost efficacy and was thus followed by a second 360-degree SLT (SLT2). Patients with prior argon laser trabeculoplasty or other glaucoma surgery, before or during the study period, were excluded.
Intraocular pressure was measured before each procedure and at one to four weeks, one to three months, five to eight months post-treatment and 15 to 21 weeks after the initial SLT.
Findings showed that the reduction in IOP was significantly less following repeat treatment at one to three months, with average decreases of -5 mmHg compared to
-2.9 mmHg after the first treatment (p=0.01), but there were no statistically significant differences between treatments at the other equivalent time points. Grading success as at least a 20-percent reduction from peak IOP, success rates for SLT1 and SLT2 were not significantly different. There was also no significant difference between eyes that re-ceived SLT2 six to 12 months after SLT1 and those that received SLT2 12 months or more after SLT1.
(J Glaucoma 2009;18:180-3)
Hong BK, Winer JC, Martone JF, Wand M, et al.
Bevacizumab and Ranibizumab Well-Tolerated
Multiple intravitreal injections of bevacizumab or ranibizumab have been shown to be both well-tolerated and safe, according to new research. The retrospective study evaluated 450 patients receiving 2,000 injections (1,275 bevacizumab and 725 ranibizumab) over the course of two years. The injections were administered in a standard, sterilized examination room. Follow-up varied from three to 24 months.
Occurrence of serious ocular adverse events was uncommon. Furthermore, results showed that only one patient developed retinal detachment (0.05 percent). The most commonly occurring procedure-related ocular adverse event was injection-site redness (64.75 percent). Postoperative subconjuctival hemorrhage occurred after 200 injections (10 percent). Patients receiving aspirin treatment were shown to be more prone to have subconjuctival hemorrhage (p=0.0002). The most common drug-related ocular adverse event was uveitis (1.90 percent), which was treated successfully and lasted no more than 12 days.
There was no statistically significant difference between the patients treated with bevacizumab or ranibizumab regarding the noted adverse events (p>0.5 percent).
Ladas ID, Karagiannis DA, Rouvas AA, et al.
Concentrated Botulinum Toxin A Better for BEB
Recent findings show that a higher concentration of botulinum toxin A may be better suited for treating benign essential blepharospasm.
The findings come from a prospective, randomized clinical trial of 16 patients with an established diagnosis of BEB. Patients were randomized to receive low concentration (the control side, 10 units per milliliter of 0.9% sodium chloride injections of botulinum toxin A) on one side and high concentration (the experimental side, 100 U/ml) injections on the other.
Patients were surveyed on a scale of one to 10 regarding pain, bruising and redness immediately after the injection. During their return visit, at an established interval of one to three months, patients were questioned regarding complications (ptosis, diplopia, tearing and dry eye), duration of relief and which side they preferred. Patients were followed over eight months for one to six repeat injections, with the side given the higher concentration alternated at each visit.
In the end, there were a total of 42 visits and 84 eyes documented. Using the Wilcoxon rank sum test, there was a statistically significant reduction in pain scores (1.94 vs. 4.59, p<0.001) on the experimental side versus the control side. Patient assessment revealed no significant difference in bruising, redness, complications of injection, side preference or length of relief of symptoms.
The side receiving the high concentration botulinum toxin A de-monstrated a 58-percent reduction in perceived pain. Despite the difference brought on by a higher concentration, patients did not report a significant difference in efficacy or complications with either dilution.
(Ophthal Plast Reconstr Surg 2009;25:81-4)
Boyle MH, McGwin G Jr, Flanagan CE, et al.