Quantitative computerized color vision testing in diabetic retinopathy: A possible screening tool?

PURPOSE: To evaluate the efficacy of a computerized color vision testing (Arden color contrast test) as a screening test for detection of diabetic macular edema (DME). MATERIALS AND METHODS: A consecutive, prospective case series of 83 eyes of 42 diabetic patients with and without macular edema was enrolled. Macular edema was assessed clinically by stereoscopic grading and by central retinal thickness measurement with optical coherence tomography (OCT). Additionally, a computerized chromatest for the protan- and tritan-axis was performed. Analysis of test characteristics included receiver operating characteristic (ROC) curves and calculated sensitivity and specificity. RESULTS: Sixty-one eyes had clinically significant macular edema (CSME). OCT yielded an area under the ROC curve (AUC) of 0.92. Color vision testing yielded an AUC of 0.82 for the tritan- and 0.80 for the protan-axis. Using a cut off of 199 microns OCT resulted in a 100% sensitivity at 39% specificity. With a cut-off of 4.85, color testing yielded a sensitivity of 100% at a specificity of 8% on the tritan-axis, respectively. Considering OCT instead of clinical examination as a reference standard resulted in a comparable high sensitivity, but low specificity for color vision testing. Disturbance of the tritan axis was more pronounced than for the protan axis in present macular edema and also better correlated (r = 0.46) with retinal thickness measured with OCT. CONCLUSIONS: Computerized, quantitative color testing using the chromatest allows detection of diabetic maculopathy with high sensitivity. However, only a low specificity exists for retinal macular edema, as in diabetic retinopathy (DR) frequently abnormalities of the tritan axis exist before any retinal thickening occurs.

Real-time intraocular pressure measurement in standard and microcoaxial phacoemulsification.

PURPOSE: To evaluate intraocular pressure (IOP) in the vitreous cavity during various stages of cataract surgery. SETTING: University Eye Hospital, Ludwig-Maximilians University, Munich, Germany. METHODS: In consecutive eyes having combined phacoemulsification, intraocular lens implantation, and pars plana vitrectomy, IOP was monitored in real time through a 25-gauge pars plana cannula connected to an external pressure transducer. Surgery was performed by standard clear corneal phacoemulsification with a 2.5 mm incision and a Mega-Tip (1.26 mm aperture) (Group 1) or by microcoaxial phacoemulsification with a CMP-Tip (0.80 mm aperture) (Group 2). RESULTS: The 2 groups had 5 eyes each. The mean IOP in Group 1 and in Group 2, respectively, was 15.9 mm Hg +/- 9.5 (SD) and 17.0 +/- 13.5 mm Hg preoperatively (P = .442), 40.1 +/- 12.7 mm Hg and 36.5 +/- 17.2 mm Hg during lens removal (P<.001), 17.6 +/- 14.2 mm Hg and 22.6 +/- 8.6 mm Hg during irrigation/aspiration (P<.001), 13.3 +/- 13.2 mm Hg and 16.3 +/- 13.1 mm Hg during IOL implantation (P = .005), and 22.9 +/- 7.0 mm Hg and 21.5 +/- 10.0 mm Hg after IOL implantation through the end of surgery (P = .329). CONCLUSIONS: Although the IOP levels were significantly lower than those in previous studies, both phacoemulsification techniques had safe IOP profiles during various steps of surgery. Real-time IOP monitoring may prevent the surgeon from inducing excessive IOP elevation during intraocular manipulation. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Comparison of intravitreal bevacizumab versus triamcinolone for the treatment of diffuse diabetic macular edema.

BACKGROUND: Our purpose was to compare the effect of triamcinolone and bevacizumab (Avastin) on the retinal thickness and functional outcome in patients with diabetic macular edema. METHODS AND MATERIALS: A collective of 32 patients, who had been treated by a single 4.0-mg intravitreal triamcinolone injection (group 1), was matched to 32 patients ('matched pairs'), who had received 3 injections of 1.25 mg of bevacizumab within 3 months in 4-week intervals (group 2). The outcome variables were changes in best corrected visual acuity (VA) and central retinal thickness 3 months after therapy. RESULTS: Both groups did not differ regarding preoperative VA and central retinal thickness measured by optical coherence tomography. The baseline mean VA was 0.72 +/- 0.39 logMAR in group 1 and 0.73 +/- 0.39 logMAR in group 2 (p = 0.709). The mean central retinal thickness measured by optical coherence tomography was 548 +/- 185 mum in group 1 and 507 +/- 192 mum in group 2. While the patients in group 1 experienced a slight increase in VA of on average 0.7 lines following a single triamcinolone injection to a mean of 0.64 +/- 0.40 logMAR (p = 0.066) after 3 months, the patients in group 2 showed almost no effect on VA with an average increase of 0.2 lines to a mean VA of 0.72 +/- 0.30 logMAR (p = 0.948) following 3 intravitreal injections of bevacizumab. Comparing the effect on VA between both groups no statistically significant difference (p = 0.115) was noted. Concerning decrease in central retinal thickness both therapies were highly effective (p < 0.001 each), again, without statistically significant difference between the groups (p < 0.128). CONCLUSION: Our data suggest that a single triamcinolone injection may be as effective as a 3 times repeated intravitreal administration of bevacizumab for the treatment of diabetic macular edema. Further prospective trials should be performed.