THE LATEST PUBLISHED RESEARCH

Ranibizumab Assessed for Treatment of Macular Edema Associated with Perfused CRVO
In an ongoing, prospective, open-label, single-center, uncontrolled study to assess the biological effect, visual acuity changes and safety of intravitreal (IVT) ranibizumab, 10 adult patients with macular edema associated with perfused central retinal vein occlusion (CRVO) were randomly assigned to receive three monthly IVT injections of either 0.3 or 0.5 mg ranibizumab (n = 5 at each dose). Additional injections were administered quarterly as needed over the ensuing 21 months at the physician's discretion for recurrent or persistent macular edema.

For investigators, the predetermined primary endpoint was the percentage of patients gaining ≥ 15 letters of best-corrected Early Treatment of Diabetic Retinopathy Study visual acuity (BCVA) and the secondary endpoints include the mean change in BCVA and central retinal thickness (CRT) measured by optical coherence tomography, the rate of progression to ischemic CRVO, extent of intraocular hemorrhage, retinal vein diameter, optic nerve head swelling and the incidence and severity of ocular and nonocular adverse events. After three, six and nine months of follow up, 40 percent; 10 percent; and 30 percent; of patients, respectively, gained ≥ 15 letters in BCVA; mean BCVA improved by 12±20 letters, 3±21 letters and 1±24 letters, respectively, compared with baseline and CRT showed a mean decrease of 272±244 µm, 88±178 µm and 119±153 µm, compared with baseline. The investigators observed no significant differences between the 0.3- and 0.5-mg doses. Most patients experienced decreases in the extent of retinal hemorrhage, retinal vein diameter and optic nerve head swelling at months three and six compared with baseline. No patients progressed to ischemic CRVO or experienced a severe adverse event that was attributed to ranibizumab.

It has been concluded from the results of this study that ranibizumab is generally well-tolerated and may improve BCVA and decrease CRT. The authors remark that the improvements in BCVA and CRT observed during the initial monthly injection period (0 to 3 months) were possibly lost to the recurrence of macular edema in between ranibizumab injection during the quarterly treatments (3 to 9 months). The extent of retinal hemorrhage, retinal vein diameter and nerve swelling continued to normalize for most of the patients from baseline to six months. Note that follow up is ongoing and alternative dosing regimens are being evaluated.

Source: Pieramici DJ, Rabena M, Castellarin AA, et al. Ranibizumab for the treatment of macular edema associated with perfused central retinal vein occlusions. Ophthalmology 2008;115(10):e47-e54.

Efficacy and Safety of Intravitreal Bevacizumab in Managing Central Retinal Vein Occlusion
Investigators evaluated the long-term safety and efficacy of intravitreal bevacizumab injection (Avastin, Genentch) for the treatment of macular edema secondary to central retinal vein occlusions through a retrospective review of eyes treated from May 2005 to August 2006 with follow up through February 2007.

Fifty-seven eyes received intravitreal bevacizumab (1.25 mg [0.05 mL]) at baseline. Retreatment was performed at monthly or longer intervals at the discretion of the treating physician. Visual acuity improved by a mean of 14 letters (n = 53; p < 0.001) at 1 month, 13 letters at 3 months (n = 53; p < 0.001), 9 letters at 6 months (n = 30; p = 0.001) and 9 letters at 12 months (n = 17; p = 0.004). The mean optical coherence tomography thickness decreased by 299 [mu]m at 1 month (n = 53; p < 0.001), 144 [mu]m at 3 months, (n = 53; p < 0.001), 127 [mu]m at 6 months (n = 30; p = 0.011) and 276 [mu]m at 12 months (n = 17; p < 0.001). No ocular or systemic events were observed; however, improvements in visual acuity and optical coherence tomography were observed during the first year following intravitreal bevacizumab for macular edema secondary to central retinal vein occlusions.

According to the authors, these retrospective results provide additional evidence to support the perceived safety and efficacy of intravitreal bevacizumab in this disorder.

Source: Source: Gregori NZ, Gaitan J, Rosenfeld PJ, et al. Long-term safety and efficacy of intravitreal bevacizumab (Avastin) for the management of central retinal vein occlusion. Retina 2008 ;28(9) :1325-1337.

Changes in Retinal Vascular Caliber Following Intravitreal Triamcinolone Treatment for DME
Researchers used prospective data from a randomized clinical trial to describe changes in retinal vascular caliber in response to a single injection of intravitreal triamcinolone (IVTA) in patients with refractory diabetic macular edema (DME). The effects of IVTA versus sham injections in patients with refractory diabetic macular edema were evaluated in a randomized clinical trial involving 69 eyes of 43 patients. Of these, 28 eyes (15 IVTA and 13 sham) of 21 patients had gradable retinal photographs at the baseline and 3-month follow up visit for analysis in the present study. They measured retinal vascular caliber from digital fundus photographs and summarized them as central retinal artery (CRAE) and vein (CRVE) equivalents in all eyes at baseline and at the three-month follow-up visit.

Over the three months of the study, the researchers noted a significant reduction compared to baseline in retinal arteriorlar (147.8 µm vs. 140.0 µm, p = 0.047) and venular (219.5 µm vs. 198 µm, p = 0.039) caliber in eyes treated with IVTA. There was no change in retinal arteriorlar (139.9 µm, p = 0.878) or venular (220.3 µm vs. 217.6 µm, p = 0.534) caliber in those treated with sham injections. They concluded that IVTA has a significant narrowing effect on both retinal arteriolar and venular diameter in eyes with DME.

Source: Wickremasinghe SS, Rogers SL, Gillies MC, et al. Retinal vascular caliber changes after intravitreal triamcinolone treatment for diabetic macular edema. Invest Ophthalmol Vis Sci 2008 ; 49 :4707-4711.

Clinical Outcome of Intravitreal Triamcinolone Acetonide Injection at the End of Vitrectomy for Diabetic Vitreous Hemorrhage
In this prospective, randomized clinical trial study, intravitreal injection of traimcinolone acetonide proved effective in the prevention of rebleeding in eyes undergoing pars plana vitrectomy for treatment of diabetic vitreous hemorrhage.

In the study, 72 consecutive patients (72 eyes) underwent pars plana vitrectomy for treatment of diabetic nonclearing vitreous hemorrhage and 38 patients received an intravitreal injection of 4 mg (0.1 cc) of triamcinolone acetonide at the end of surgery. Main outcome measures were rate of recurrent early vitreous hemorrhage, reoperation, intraocular pressure (IOP), visual acuity and incidence of cataract formation. Mean follow-up time was 6 months.

Rate of early rebleeding and reoperation were lower in patients taking intraveitreal triamcinolone (p = 0.003 and 0.03, respectively) and visual acuity six months after operation was better in study group (p < 0.001). It was also noted that mean IOP was higher one day and one week after the procedure in the study group compared with the control group (p < 0.001 and 0.002, respectively), but in other times, its differences were not significant Also, no significant difference in rate of nuclear sclerosis and cortical cataract formation and other complication was noted between the two groups. There was, however, a significantly increased rate of posterior subcapsular progression in a dose-dependent manner in the study group vs. control (p = 0.011).

Source: Faghihi H, Taheri A, Farahvash MS, et al. Intravitreal triamcinolone acetonide injection at the end of vitrectomy for diabetic vitreous hemorrhage: a randomized, clinical trial. Retina 2008 ;28(9) :1241-1246.

OCT Findings Provide Information on CNV Lesions
To compare the volume of various spaces visible on optical coherence tomography (OCT) images in different angiographic lesion subtypes of neovascular age-related macular degeneration (AMD), 66 cases of previously untreated, active subfoveal choroidal neovascularization (CNV) associated with AMD were retrospectively collected. The CNV lesions were classified as occult with no classic CNV, minimally classic CNV, predominantly classic CNV or CNV lesions with associated retinal angiomatous proliferation (RAP) and corresponding OCT image sets were analyzed by trained graders using previously validated custom software. Spaces delineated by these boundaries included the neurosensory retina, subretinal fluid, subretinal tissue and pigment epithelial detachments (PEDs). Volume measurements were calculated by the software and compared among groups.

Minimally and predominantly classic CNV membranes demonstrated subretinal tissue on OCT in all cases and appeared to show a significantly greater volume of subretinal tissue than did the occult membranes. Subretinal fluid was present in all of the predominantly classes cases and a PED was visible in all of the occult CNV cases in our study, demonstrating less retinal thickening and significantly greater PED volumes than minimally and predominantly classic CNV lesions. Lesions associated with RAP were found to have the highest percentage of cystoid spaces.

Complementary information regarding CNV lesions can be obtained with OCT and angiography and more specifically, quantitative analysis of OCT images allows for an improved understanding of the anatomic characteristics of angiographically defined CNV lesion subtypes.

Source: Liakopoulos S, Ongchin S, Bansal A, et al. Quantitateive optical coherence tomography findings in various subtypes of neovascular age-related macular degeneration. Invest Ophthalmol Vis Sci 2008 ;49 :5048-5054.

Initial Results of Implantable Telescope for End-Stage AMD
Long-term results of this prospective, open-label clinical trial with fellow-eye controls show the substantial best-corrected visual acuity (BCVA) improvement at one year with a telescope prosthesis is maintained at two years. In the trial, investigators sought to evaluate long-term safety and BCVA results of a telescope prosthesis in patients with end-stage age-related macular degeneration (AMD). Patients with end-stage AMD (bilateral geographic atrophy or disciform scars; BCVA, 20/80 to 20/800) received the telescope prosthesis at 28 centers. Methods were similar to those described in the one-year results, with follow-up visits continuing at 18 and 24 months. Main outcome measures included BCVA change from baseline, endothelial cell density (ECD) and morphometry as well as incidence of complications.

The investigators analyzed data from 174 (92.6 percent) of 188 available patients at two years. Overall, 103 (59.5 percent) of 173 telescope-implanted eyes gained three lines or more (doubling of visual angle) of BCVA compared with 18 (10.3 percent) of 174 fellow control eyes (p < .0001). Mean BCVA improved 3.6 liens (standard deviation [SD], 1.9 lines) and 2.8 lines (SD, 2.3 lines) from baseline in eyes with the 3X and 2.2X device models, respectively. They found that mean endothelial cell density (ECD) stabilized through two years, with 2.4 percent mean cell loss occurring from one to two years. According to the investigators, there was no significant change in coefficient of variation or percentage of hexagonal endothelial cells from within six months to two years after surgery. The most common complication was inflammatory deposits.

Key indicators of corneal healing demonstrate ECD change that reflects remodeling of the endothelium associated with the implantation procedure. ECD stabilizes over time, and there is no evidence of any ongoing endothelial trauma.

Source: Hudson HL, Stulting RD, Heier JS, et al ; IMT002 Study Group. Implantable telescope for end-stage age-related macular degeneration: long-term visual acuity and safety outcomes. Am J Ophthalmol 2008 ;146(5) :664-673.e1.

Correlation of Factors with Visual Outcome After Vitrectomy for VMT
In a retrospective review of 24 eyes of 24 patients with macular edema due to vitreomacular traction (VMT) who underwent vitrectomy to relieve macular traction, the authors evaluated the relationship between preoperative structure and surgical outcome in eyes with macular edema caused by VMT. The diagnosis of VMT was based on findings of clinical examination and optical coherence tomography (OCT). Preoperative and postoperative best-corrected visual acuity was converted to logarithm of the minimal angle of resolution visual acuity for analysis. Patients with a minimum of 6 months of follow up were included.

The authors categorized eyes into one of three groups based on the relationship of the posterior hyaloid to the retina: Group 1 (11 eyes) had focal vitreofoveal hyaloidal attachment with perifoveal separation; Group 2 (6 eyes) had vitreoretinal hyaloidal attachment to the macula and papillomacular bundle; and Group 3 (7 eyes) had broad vitreofoveal attachment with a fine epiretinal membrane over the posterior pole.

Mean postoperative follow up was 9.8 months (range, 6-15 months). Twenty-one eyes (87.5 percent) had at least one line of improvement in visual acuity (logMAR). Improvement in vision was significantly greater in the eyes in Group 1 (2.82 ± 1.47 lines) than in those in Group 2 (0.83 ± 1.17 lines; p = 0.004) or Group 3 (1.29 ± 0.49 lines; p = 0.036). Visual outcome correlated with symptom duration (p = 0.024), VMT category (Group 1, 2 or 3; p = 0.013) and preoperative central macular thickness (CMT) by OCT (p = 0.007). The authors found that a decrease in mean CMT was also significantly correlated with VMT configuration (Group 1, 2 or 3; p = 0.041).

Visual outcome after vitrectomy for VMT is correlated with preoperative vitreomacular structure, duration of symptoms and preoperative CMT.

Source: Sonmez K, Capone A, Trese MT, Williams GA. Bitreomacular traction syndrome: impact of anatomical configuration on anatomical and visual outcomes. Retina 2008 ;28(9) :1297-1214.