Accuracy of newer intraocular lens power formulas in short and long eyes using sum-of-segments biometry.

PURPOSE: To analyze the accuracy of newer intraocular lens power formulas in long and short eyes measured using the sum-of-segments biometry. SETTING: Private practice, Lynwood, California. DESIGN: Retrospective observational study. METHODS: 595 patients scheduled for cataract surgery had their eyes measured using the sum-of-segments biometry. The expected residual refractions were calculated using Barrett Universal II (B II), Barrett True Axial Length (BTAL), Emmetropia Verifying Optical (EVO), Hill-RBF, Hoffer QST, Holladay 2, Holladay 2-NLR, K6, Kane, Olsen, PEARL-DGS, T2, and VRF formulas and compared with the traditional Haigis, Hoffer Q, Holladay 1, and SRK/T formulas. RESULTS: In the 102 long eyes, all new formulas had a mean absolute error (MAE) equal or lower than the traditional formulas, ranging from 0.29 to 0.32 diopter (D). In the 78 short eyes, BTAL, EVO, Hoffer QST, K6, Olsen, and PEARL-DGS formulas had the lowest MAE (0.33 D, 0.33 D, 0.31 D, 0.36 D, 0.32 D, and 0.32 D, respectively), whereas all traditional formulas exceeded 0.36 D. CONCLUSIONS: All new formulas performed equal or better than the traditional formulas with the sum-of-segments biometry. The best overall results in the short and long eyes as well as in the very short and very long eyes were noted with the BTAL, EVO, Hoffer QST, K6, Olsen, and PEARL-DGS formulas, closely followed by the B II and Kane formulas.

Effects on IOL Power Calculation and Expected Clinical Outcomes of Axial Length Measurements Based on Multiple vs Single Refractive Indices.

PURPOSE: To compare axial length measurements based on multiple specific refractive indices for each segment of the eye to those obtained using a single refractive index for the entire eye and to evaluate the subsequent effects on IOL power calculation. SETTING: One site in Lynwood, CA. DESIGN: Single-arm, non-interventional, non-randomized retrospective chart review. METHODS: Eyes undergoing cataract surgery where biometry and IOL power calculations were based on axial length calculated with multiple specific refractive indices (multiple) were evaluated. A simulated axial length based on using a single refractive index was calculated for each case (single). The expected residual refractions based on different IOL formulas were calculated for both single and multiple groups. Formulas were then optimized, and the mean prediction errors (MPE) and mean absolute prediction errors (MAE) were calculated, based on the difference between the (optimized) expected value and the actual refractive outcome. RESULTS: A total of 595 eligible eyes were evaluated. Differences between the axial lengths determined in the single and multiple groups ranged from +0.28 mm to -0.14 mm, with a significant correlation between the difference in AL and average AL (r2 = 0.73, p < 0.001). AL differences between groups were statistically significant in long and short eyes (p < 0.001) but not in average eyes or overall (p > 0.25). In nearly all cases, the average MPE in the multiple group was lower than that for the single group across all axial lengths and formulas. When larger differences in MAE were present, the multiple group results were more often lower (better). CONCLUSION: Differences were found between axial lengths calculated using a single refractive index and multiple refractive indices, mainly in the short and long eyes. Differences had some effect on IOL power calculation. Such effects may become increasingly important as the precision of formulas increases.

Superior Limbic Keratoconjunctivitis-like Inflammation in Patients with Chronic Graft-Versus-Host Disease.

PURPOSE: Describe the presentation and management of superior limbic keratoconjunctivitis (SLK)-like inflammation and secondary limbal stem cell dysfunction in the setting of ocular chronic graft-versus-host disease (cGVHD). METHODS: Retrospective observational case series in a multicenter clinical practice. Participants were 13 patients (26 eyes) with ocular cGVHD and SLK-like inflammation presenting to the University of Illinois at Chicago and BostonSight® between January 1, 2009 and July 1, 2013. MAIN OUTCOME MEASURES: 1) Reversal or worsening of SLK, and 2) development of limbal stem cell dysfunction. RESULTS: All eyes showed evidence of SLK-like inflammation and superior limbal stem cell dysfunction manifested by conjunctival injection and superior conjunctival and corneal staining. In addition to aggressive lubrication, management strategies for SLK included topical steroids (20/26), punctal occlusion (18/26), topical cyclosporine (24/26), autologous serum tears (12/26), therapeutic soft contact lens (13/26 eyes) and scleral lenses (4/26 eyes). SLK and limbal stem cell dysfunction were reversed in 23/26 eyes. Three eyes of two patients with long-standing disease demonstrated frank limbal stem cell deficiency (LSCD) and corneal pannus, with one patient requiring multiple reconstructive surgical procedures. CONCLUSIONS: SLK-like inflammation is an under-recognized condition in patients with severe dry eyes secondary to ocular cGVHD. Untreated SLK can potentially lead to permanent LSCD over time. Early recognition and management of SLK in ocular cGVHD can improve vision, reverse signs, and may prevent these long-term consequences.

Improving the second-eye refractive error in patients undergoing bilateral sequential cataract surgery.

PURPOSE: To assess the refractive error in the second eye to undergo surgery when the intraocular lens (IOL) power was modified to correct 50% of the error from the first eye when such an error exceeded 0.50 diopter (D). DESIGN: Prospective, observational case series. PARTICIPANTS: Two hundred fifty patients with bilateral, sequential cataract surgery. METHODS: Two hundred fifty consecutive patients who underwent the first-eye cataract operation 1 to 3 months earlier were scheduled for cataract surgery in the second eye. When choosing the IOL power for the second eye, the calculations were adjusted to correct 50% of the first-eye refractive error (FERE). The adjusted second-eye refractive error (aSERE) was evaluated 6 to 8 weeks after surgery. It was compared with the FERE, with a potential nonadjusted SERE, and with a potential fully adjusted SERE. MAIN OUTCOME MEASURES: Postoperative refractive error. RESULTS: The median aSERE was significantly lower in the second eye compared with the median FERE in the 47 cases in which the FERE ranged from -0.50 to -1.00 D (-0.12 vs. -0.66 D), in the 15 cases in which the FERE exceeded -1.00 D (-0.12 vs. -1.25 D), in the 24 cases in which the FERE ranged from 0.50 to 1.00 D (-0.03 vs. 0.65 D), and in the 11 cases in which the FERE exceeded 1.00 D (-0.29 vs. 1.19 D). The difference was statistically significant in all categories (P<0.00001). CONCLUSIONS: In patients undergoing bilateral sequential cataract surgery and in cases in which the FERE exceeded 0.50 D, the refractive error of the second eye can be improved by modifying the IOL power to correct up to 50% of the error from the first eye. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Distinguishing wet from dry age-related macular degeneration using three-dimensional computer-automated threshold Amsler grid testing.

BACKGROUND/AIMS: With the increased efficacy of current therapy for wet age-related macular degeneration (AMD), better ways to detect wet AMD are needed. This study was designed to test the ability of three-dimensional contrast threshold Amsler grid (3D-CTAG) testing to distinguish wet AMD from dry AMD. METHODS: Conventional paper Amsler grid and 3D-CTAG tests were performed in 90 eyes: 63 with AMD (34 dry, 29 wet) and 27 controls. Qualitative comparisons were based upon the three-dimensional shapes of central visual field (VF) defects. Quantitative analyses considered the number and volume of the three-dimensional defects. RESULTS: 25/34 (74%) dry AMD and 6/29 (21%) wet AMD eyes had no distortions on paper Amsler grid. Of these, 5/25 (20%) dry and 6/6 (100%) wet (p=0.03) AMD eyes exhibited central VF defects with 3D-CTAG. Wet AMD displayed stepped defects in 16/28 (57%) eyes, compared with only 2/34 (6%) of dry AMD eyes (p=0.002). All three volumetric indices of VF defects were two- to four-fold greater in wet than dry AMD (p<0.006). 3D-CTAG had 83.9% positive and 90.6% negative predictive values for wet AMD. CONCLUSIONS: 3D-CTAG has a higher likelihood of detecting central VF defects than conventional Amsler grid, especially in wet AMD. Wet AMD can be distinguished from dry AMD by qualitative and quantitative 3D-CTAG criteria. Thus, 3D-CTAG may be useful in screening for wet AMD, quantitating disease severity, and providing a quantitative outcome measure of therapy.

Evaluation of optical coherence tomography retinal thickness parameters for use in clinical trials for neovascular age-related macular degeneration.

PURPOSE: To investigate the relationship between automated and manually derived measurements of central retinal thickness from optical coherence tomography (OCT) and to determine the relationship between the foveal center point (FCP) and the foveal central subfield (FCS) in neovascular age-related macular degeneration (AMD). METHODS: Data were collected from 216 patients with newly diagnosed neovascular AMD, who underwent StratusOCT imaging at diagnosis. Raw StratusOCT images for each patient were analyzed with the publicly available custom software OCTOR, which allows accurate manual grading of OCT B-scans. Manually derived central retinal thickness measurements were compared with measurements obtained from automated StratusOCT analysis. Manually obtained measurements of FCP and FCS were also compared. RESULTS: The mean (+/-SD) difference in thickness between automated and manually derived FCP thickness was 7.9 microm (+/-90.8), but the maximum difference was 455 microm. The limits of agreement (95% confidence interval), between automated and manually obtained FCP thicknesses, were -173.7 microm (lower limit) and 189.6 microm (upper limit), with a coefficient of determination (R(2)) of 0.49 (P < 0.001). In contrast, the R(2) for manually derived FCP and manually derived FCS thickness was 0.94 (P < 0.001), with a smaller mean (+/-SD) difference in thickness of 13.8 microm (+/-29.8). CONCLUSIONS: Manual correction of errors in automated OCT segmentation may be necessary for accurate interpretation of anatomic outcomes for clinical trials of neovascular AMD. In addition, although measurement of FCS remains preferable for assessment of central retinal thickness, accurate measurement of FCP may represent an adequate alternative when FCS is unavailable.

Effect of ranibizumab retreatment frequency on neurosensory retinal volume in neovascular amd.

PURPOSE: To determine the characteristics of patients with neovascular age-related macular degeneration who show initial anatomic improvements on optical coherence tomography in response to treatment with ranibizumab, but who subsequently regress toward their anatomic baseline. METHODS: Data from 50 consecutive patients, receiving ranibizumab therapy for neovascular age-related macular degeneration, were collected. Raw StratusOCT images were analyzed using custom software ("OCTOR"). Changes in volume of neurosensory retina at months 1, 3, and 6 were calculated. Baseline demographic and morphologic characteristics were compared. RESULTS: Forty-two patients (84%) showed a reduction in total retinal volume 1 month after initial treatment with ranibizumab. Of the patients that initially showed a reduction, 16 (38%) maintained this reduction through month 6, whereas 26 patients (62%) demonstrated a subsequent increase in retinal volume. Patients who maintained a reduction in edema received 3.75 +/- 1.18 injections of ranibizumab versus 2.96 +/- 1.34 injections for patients who did not (P = 0.049). Regression of initial anatomic improvements was associated with worsening of visual acuity (r = 0.599, P = 0.002). CONCLUSION: Patients receiving fewer injections of ranibizumab appeared less likely to maintain anatomic improvements achieved following commencement of ranibizumab therapy; regression of these improvements was associated with deterioration in visual acuity.

Quantitative analysis of central visual field defects in macular edema using three-dimensional computer-automated threshold Amsler grid testing.

PURPOSE: To evaluate the central visual field (CVF) with specialized Amsler grid testing methods that include contrast sensitivity evaluation, in an attempt to detect abnormalities not identified with standard methods and to define new patterns of CVF deficits in two different diseases. METHODS: 3D computer-automated threshold Amsler grid testing (3D-CTAG) was performed at five levels of contrast in one eye of 37 patients with diabetic macular edema (DME, n = 16) and exudative age-related macular degeneration (AMD, n = 21). RESULTS: 3D-CTAG abnormalities were detected in six patients (16%) who had no abnormalities with conventional Amsler grid testing. DME patients had more foci of CVF deficits (3.56 +/- 2.92 defects/eye), than AMD patients (1.24 +/- 0.89 defects/eye; P < 0.0002). The shape of the 3D-CTAG abnormality in DME was an inverted cone, while the deficits in AMD were always cylindrical. All eyes showed significant increases in CVF deficit surface area at minimum contrast levels when compared to maximum contrast (295% greater with DME, P < 0.02 and 150% greater with AMD, P < 0.03). CONCLUSION: 3D-CTAG detected CVF abnormalities not identified with conventional Amsler grid testing in 16% of subjects. Low-contrast conditions elicited a larger defect in both DME (3-fold) and AMD (1.5-fold). DME and AMD have unique 3D-CTAG profiles, enabling diagnostic discrimination. Measuring CVF defects with 3D-CTAG can quantitatively index disease severity and may be useful in longitudinal studies of the natural history of disease, as well as providing a quantitative outcome measure of the response to therapy.