Findings at this years ARVO meeting run the gamut from compliance and nutrional benefits to surgical success rates and the impact of gene variants on a patients likelihood to develop glaucoma.
At this years ARVO, results from the International Collaborative Exfoliation Syndrome Treatment (ICEST) Study were published.2474/A149 The study examined treatment with latanoprost with pilocarpine vs. timolol vs. fixed-combination timolol/dorzolamide in eyes with exfoliation syndrome and elevated IOP. Researchers in
Medications, Compliance and Nutrition
Over a six-month period, researchers in Mexico and California found that a fixed dose of timolol/brimonidine/dorzolamide more effectively reduced IOP than a fixed-combination of timolol/dorzolamide.2478/A153 In this multicenter, double-masked, randomized clinical trial, 112 patients with either open-angle glaucoma or ocular hypertension used one of the two drug formulations. At six months, mean IOP change from baseline to conclusion was significantly greater in the timolol/brimonidine/dorzolamide groupa difference of 9.90mm Hg 2.95mm Hgthan in the timolol/dorzolamide group, which demonstrated a difference of 6.8mm Hg 3.42mm Hg. And, researchers note that a fixed combination drug seems to improve patient compliance by reducing the total amount of drops per day. This new pharmaceutical combination agent may soon become available in the
Does education actually have an impact on patients compliance? Absolutely, say researchers in
Vitamins may aid in the management of glaucoma, say researchers in Los Angeles.2071 In this study, 52 patients with primary open-angle glaucoma (POAG) and 19 control subjects underwent ophthalmic evaluation, dietary intake assessment and serum level measurement.
Researchers found that, though there were no statistically significant differences in dietary intake, serum levels of alpha-carotene and lutein were significantly lower in the glaucoma group than in the control group38g/L vs. 106g/L for alpha-carotene and 111g/L vs. 189g/L for lutein. So, vitamins may play a role in the management of POAG, if properly understood.
CCT, Oxygen and Thin Corneas: Higher Risk?
Measurement of central corneal thickness (CCT) may not suffice when differentiating between healthy and glaucomatous eyes, found researchers in
But, how stable is CCT in patients with high-risk ocular hypertension or early glaucoma? Not very, say researchers in
Much research of late has focused on identification of genetic predisposition toward glaucoma.
Researchers in Durham, N.C., set out to identify links between additional gene variants and POAG, and found that a gene linked to Alzheimers disease may be related to POAG as well.881/A467 Dynamin-binding protein is associated with late-onset Alzheimers disease in Belgian and Japanese populations; however, when it is combined with coding variant C1413W, the protein results in an increased association with POAG in a white population.
Variants in the gene LOXL1 contribute to the formation of abnormal fibers characteristic of pseudoexfoliation glaucoma, say researchers in
But, some of the polymorphisms of LOXL1 do not influence IOP, CCT or cup-to-disc ratio, say researchers in Greece and Texas.867/A453 In this clinical and genetic study, 600 villagers from one Greek town were enrolled (376 villagers were linked in one 11-generation line). Two variants of LOXL1 were mapped and found to not affect CCT, IOP or cup-to-disc ratio. In one subset, however, there was a significant association between one variation, rs3825942, and CCT in cases of POAG. Otherwise, the LOXL1 variants did not play a significant role, but the study population was limited.
Lastly, single nucleotide polymorphisms (SNPs) within LOXL1 may play a critical role in the pathogenesis of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG), say researchers in Italy.878/A464 In a cohort of 73 unrelated patients who had either PDS or PG, researchers found a strong association between the combined LOXL1 SNPs and PDS or PG.
Studies at this years meeting definitively confirm the significant importance of blood flow in the glaucoma process.
Reduced blood flow in the optic nerve head is associated with an increased degree of visual field defect and to the glaucomatous disease process, found researchers in Austria and Germany.5868/A206 Examination of 103 patients with POAG revealed that optic nerve head blood flow was negatively correlated with cup-to-disc ratio and positively correlated to retina nerve fiber layer (RNFL) cross section.
Wait and see is a viable approach to attaining accurate disease progression measurement, say researchers in London.1669 Rather than perform three visual field tests over the period of two years (the current suggested method of estimating rapid progression), researchers created a simulation of patients and control subjects and tested them every four months, or three times at baseline and three times at two years. And, they recorded the time until detection. In the group of patients tested every four months, 83% were diagnosed correctly with rapid progression by two years. But, 95% were identified in the wait and see group. Also, rate of loss was better estimated in this group, though identification was slightly quicker (a difference of 3.1 months) in the four-month group. Rapid progression may be more reliably predicted with fewer false positives and one fewer visual field if we wait and see.
Also, visual field loss may indicate areas of imminent disc hemorrhage, found researchers in
Ages Effects on the Cornea and Glaucoma Risk How does aging affect corneal biomechanical properties, such as corneal hysteresis, CCT and corneal resistance factornot to mention, IOP? Researchers in
Ages Effects on the Cornea and Glaucoma Risk
How does aging affect corneal biomechanical properties, such as corneal hysteresis, CCT and corneal resistance factornot to mention, IOP? Researchers in
How successful is the modern trabeculectomy in POAG when using the safe surgery system, ask researchers in Portsmouth, United Kingdom.168/A268 The answer: The safe surgery system is effective in the management of POAG when paired with close monitoring and prompt intervention, as needed.
Researchers followed patients who had POAG and no history of previous glaucoma surgery. Of the 98 eyes followed, 95 surpassed the criteria for qualified successof these, 91 achieved complete success. Two patients procedures failed due to conservative postoperative management, and one patient required a redo. Ten patients developed cataract, but subsequent phacoemulsification and IOL insertion were uncomplicated.
Not only can SLT affect IOP, but also trabecular outflow facility (TOF), say researchers in London.154/A254 In patients with POAG or ocular hypertension (OHT), one eye received either 180 or 360 of treatment with SLT. Fellow eyes that did not require treatment were used as controls. Over the course of one month, eyes in the 180 group demonstrated IOP reduction from 24.4mm Hg 4.1mm Hg to 19.0mm Hg 5.2mm Hg and TOF increase from an average of 0.08 to 0.11. Results in the 360 group were similar. Overall, SLT treatment, either 180 or 360, reduced IOP by 29% and increased TOF by 38%.
Another procedure that can safely lower IOP in POAG patients is canaloplasty, say researchers in
Is it better to perform only phacoemulsification (phaco) or to perform it in tandem with endocyclophotocoagulation (ECP)? Researchers in
Both treatment methods equally reduced patients dependency on medications, though, reducing it to about 2.0a statistically insignificant difference.
For the text of each abstract, referenced here by presentation number, please go to www.arvo.org.