Abstract
Purpose :
Several studies showed the important role that vascular endothelial growth factor (VEGF) plays in the pathogenies of DME, and the efficiency of anti-VEGF drugs in stabilizing, preventing and even recovering visual impairment.
These studies did not include patients with very low vision, such as with visual acuity worse than 20/200 or 20/320. However, this treatment is very commonly performed for these patientes in clinical practice. In this study, our objective is to evaluate the efficacy of the administration of bevacizumab in patients with diabetic macular edema for patients with visual acuity worse than 20/200.
Methods :
Patients selected were the ones with visual acuity worse than 20/200, verified with Snellen optometric scale, located at four meters of distance from the patient. The visual acuity was converted to logMAR (logarithm of minimal angle of resolution).Assessment of macular thickness was performed with the use of optical coherence tomography (OCT; Spectral Domain, Spectralis, Heidelberg, Germany). We evaluated patients before and after treatment with pro re nata intravitreal injection of bevacizumab.
Results :
Twenty patients were followed in a variable period over three to eight months, and the total number of injections varied from three to six. Ten of them were men, and 10 were women. All of the patients had high blood pressure and diabetes. The mean age was 68,2 ± 8,06 years old, with history of diabetes for 18,45 ± 8,5 years. The follow-up time was 5,2 ± 1,79 months. Five eyes were previously subjected to cataract surgery and 15 eyes had history of panphotocoagulation.
The mean thickness of central macula was 516,05 before the injection and 405,7 after the treatment, as revealed in table 1. This shows an statistically significant reduction (p<0,05). However, there was no statistically significant improvement in visual acuity after the treatment, that went from logMAR 1,35 to 1,16 (p= 0,2005), as illustrated in table 2.
Conclusions :
Photoreceptor damage plays a significant role for the absence of visual acuity improvement despite macular edema reduction in these patients. Future developments in OCT can bring us more information about the density of the photoreceptors and the size and location of changes in the photoreceptor layer. This will be important information to determine the potential for recovery.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.