ABSTRACT.Purpose: This study aimed to compare preoperatively calculated and postoperatively achieved refraction following phacoemulsification and intraocular lens (IOL) implantation combined with pars plana vitrectomy with internal limiting membrane or epiretinal membrane removal. Methods: Twelve eyes of 12 patients who underwent a combined procedure were enrolled in this study. Ultrasound axial length and macular thickness (optical coherence tomography, OCT) measurements were performed pre-and postoperatively. Intraocular lens power was calculated with the SRK ⁄ T formula and the planned refraction was compared with results of postoperative automatic refractometry. Comparisons between IOL calculations using the measured axial length and calculations using an adjusted axial length (by adding the macular thickness measured on OCT to the ultrasound axial length) were also performed. Results: Axial length increased (p ¼ 0.02), whereas macular thickness decreased (p ¼ 0.002). The planned refraction was 0.63 ± 0.38 dioptres, whereas the postoperative refraction error was ) 0.16 ± 0.48 D (p ¼ 0.02), with a mean difference of ) 0.79 ± 0.24 D. During case-to-case comparisons, differences were observed between IOL calculations using the measured axial length and calculations using an adjusted axial length (0.63 ± 0.38 D versus 0.13 ± 0.48 D, p ¼ 0.005). Correlation analysis showed a significant relationship between the 'adjusted planned' and the measured postoperative ametropia (r ¼ 0.93, p < 0.001). Conclusions: The observed myopic shift due to erroneous IOL calculation results from underestimation of the axial length due to a thicker macula and calls for preoperative adjustment of ultrasound axial length when biometry is performed by this method.

Abstract. We determine the reliability and reproducibility of retinal thickness measurements with a custom-built OCT retinal image analysis software ͑OCTRIMA͒. Ten eyes of five healthy subjects undergo repeated standard macular thickness map scan sessions by two experienced examiners using a Stratus OCT device. Automatic/semi automatic thickness quantification of the macula and intraretinal layers is performed using OCTRIMA software. Intraobserver, interobserver, and intervisit repeatability and reproducibility coefficients, and intraclass correlation coefficients ͑ICCs͒ per scan are calculated. Intraobserver, interobserver, and intervisit variability combined account for less than 5% of total variability for the total retinal thickness measurements and less than 7% for the intraretinal layers except the outer segment/ retinal pigment epithelium ͑RPE͒ junction. There is no significant difference between scans acquired by different observers or during different visits. The ICCs obtained for the intraobserver and intervisit variability tests are greater than 0.75 for the total retina and all intraretinal layers, except the inner nuclear layer intraobserver and interobserver test and the outer plexiform layer, intraobserver, interobserver, and intervisit test. Our results indicate that thickness measurements for the total retina and all intraretinal layers ͑except the outer segment/RPE junction͒ performed using OCTRIMA are highly repeatable and reproducible.

No abstract

Abstract. Purpose: To compare thickness measurements between Fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT images analyzed with a custom-built OCT retinal image analysis software (OCTRIMA). Methods: Macular mapping (MM) by StratusOCT and MM5 and MM6 scanning protocols by an RTVue-100 FD-OCT device are performed on 11 subjects with no retinal pathology. Retinal thickness (RT) and the thickness of the ganglion cell complex (GCC) obtained with the MM6 protocol are compared for each early treatment diabetic retinopathy study (ETDRS)-like region with corresponding results obtained with OCTRIMA. RT results are compared by analysis of variance with Dunnett post hoc test, while GCC results are compared by paired t-test. Results: A high correlation is obtained for the RT between OCTRIMA and MM5 and MM6 protocols. In all regions, the StratusOCT provide the lowest RT values (mean difference 43 ± 8 μm compared to OCTRIMA, and 42 ± 14 μm compared to RTVue MM6). All RTVue GCC measurements were significantly thicker (mean difference between 6 and 12 μm) than the GCC measurements of OCTRIMA. Conclusion: High correspondence of RT measurements is obtained not only for RT but also for the segmentation of intraretinal layers between FD-OCT and StratusOCT-derived OCTRIMA analysis. However, a correction factor is required to compensate for OCT-specific differences to make measurements more comparable to any available OCT device. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

The analysis of ERG in the fellow eyes of patients with macular hole seems clinically useful. The lower amplitude may forecast the propensity for subsequent development of a macular hole. Patients with low central ERG amplitude and lower ring ratios in the healthy fellow eyes should have stricter follow-up.