Fina C. Barouch

Randomized trial of anesthetic methods for intravitreal injections.

Purpose: To compare the effectiveness of four different anesthetic methods for intravitreal injection. Methods: Twenty-four patients each received four intravitreal injections using each of four types of anesthesia (proparacaine, tetracaine, lidocaine pledget, and subconjunctival injection of lidocaine) in a prospective, masked, randomized block design. Pain was graded by the patient on a 0 to 10 scale for both the anesthesia and the injection. Results: The average combined pain scores for both the anesthesia and the intravitreal injection were 4.4 for the lidocaine pledget, 3.5 for topical proparacaine, 3.8 for the subconjunctival lidocaine injection, and 4.1 for topical tetracaine. The differences were not significant (P = 0.65). There were also no statistical differences in the individual anesthesia or injection pain scores. Subconjunctival lidocaine injection had the most side effects. Conclusion: Topical anesthesia is an effective method for limiting pain associated with intravitreal injections.

Anti-vascular endothelial growth factor strategies for the treatment of choroidal neovascularization from age-related macular degeneration.

At least 1.7 million individuals in the U.S. have impaired vision as a result of age-related macular degeneration (AMD). Choroidal neovascularization (CNV) in patients with AMD is the leading cause of irreversible vision loss in the elderly. Neovascularization derived from choroidal blood vessels usually breaks through Bruch’s membrane and grows into the subretinal pigmented epithelial (RPE) space. Neovascularization can also extend through the RPE into the subretinal space and result in the exudation of serum and blood in the subretinal and sub-RPE spaces, resulting in distorted and decreased vision. Fluorescein angiography is often useful in the identification of CNV, but RPE cells can proliferate and surround the new blood vessels and obscure some or all of the CNV. Thus, fluorescein angiography defines 2 types of CNV: classic CNV and occult CNV. Classic CNV is characterized by an area of well-demarcated hyperfluorescence that is seen in the early phase of the angiogram with progressive leakage and obscuration of the borders of the CNV. Occult CNV encompasses many fluorescein angiographic appearances that do not conform to the description of classic CNV including fibrovascular pigment epithelial detachments (PEDs) and late leakage of undetermined source. In fibrovascular PEDs, areas of irregular elevation of the RPE are seen as areas of stippled hyperfluorescence that are not as bright or as discrete as areas of classic CNV and that show staining or leakage in the late frames of the angiogram. Late leakage of undetermined source consists of areas of late fluorescein leakage with pooling of dye in the overlying subsensory retinal space, in which there is no corresponding well-demarcated area of hyperfluorescence in the early frames of the angiogram. Indocyanine green angiography has been used to further characterize occult CNV.

The role of inflammation and infection in age-related macular degeneration.

Age-related macular degeneration (AMD) affects more than 1.75 million individuals in the United States and is the leading cause of blindness in persons over the age of 65 in Western countries. The earliest signs of AMD include drusen and changes in the retinal pigment epithelium (RPE). Late changes include geographic atrophy and choroidal neovascularization (CNV). AMD is broadly classified into dry and neovascular forms. Dry AMD is characterized by the presence of drusen (localized deposits between the RPE and Bruch’s membrane) and geographic atrophy (areas of localized RPE cell death with overlying photoreceptor atrophy), whereas neovascular AMD is characterized by CNV. CNV accounts for 10% of cases of AMD but advanced AMD (geographic atrophy involving the macular center and neovascular AMD) causes 90% of visual loss. AMD is a complex disorder that is associated with a number of demographic, genetic, and environmental factors. Increasing evidence has suggested a role for local and systemic inflammation in the pathogenesis of this disease. Risk factors associated with AMD include advanced age, cigarette smoking, race, family history, body mass index (BMI), underlying cardiovascular disease, and systemic inflammatory markers such as C-reactive protein (CRP). Some of these risk factors may predispose individuals to AMD by inflammatory mechanisms. Genetic factors may also lead to AMD by inflammatory mechanisms. Recently, several groups have determined that a variant of the gene encoding complement factor H (CFH), the Tyr402His polymorphism, is strongly associated with the development of AMD in whites.5–7

Changes in flare after intravitreal injection of three different anti-vascular endothelial growth factor medications.

Purpose: To compare the change in anterior chamber flare after intravitreal injection of the anti-vascular endothelial growth factor agents bevacizumab, aflibercept, and ranibizumab. Methods: Sixty-one eyes of 53 patients underwent intravitreal injection with anti-vascular endothelial growth factor medications for exudative age-related macular degeneration, diabetic macular edema, or retinal vein occlusion. There were a total of 26 eyes injected with bevacizumab, 14 eyes injected with aflibercept, and 21 eyes injected with ranibizumab. Anterior segment flare was measured with a laser flare meter (Kowa) before intravitreal injection and 1 day after injection. The change in flare was analyzed. Results: The mean change in flare after 1 day was +2.5 photons per millisecond in patients who received bevacizumab, 0.0 photons per millisecond for aflibercept, and −0.2 photons per millisecond for ranibizumab. There was a statistically significant difference between the 3 medications (P = 0.006). Pairwise analysis of the change in flare showed a statistically significant difference between bevacizumab and ranibizumab (P = 0.002). The change in flare in patients who received aflibercept was not different from that in those who received bevacizumab (P = 0.08) or ranibizumab (P = 0.99). Conclusion: There was a statistically significant increase in flare after bevacizumab injection compared with ranibizumab. This difference was small and is not believed to be clinically significant. There was no statistical difference in the change in flare between aflibercept and the other medications, although the number of eyes in the aflibercept group was small.