Calculation of ocular magnification in phakic and pseudophakic eyes based on anterior segment OCT data.

PURPOSE: The purpose of this study is to develop a straightforward mathematical concept for determination of object to image magnification in both phakic and pseudophakic eyes, based on biometric measures, refractometry and data from an anterior segment optical coherence tomography (OCT). METHODS: We have developed a strategy for calculating ocular magnification based on axial length measurement, phakic anterior chamber and lens thickness, keratometry and crystalline lens front and back surface curvatures for the phakic eye, and axial length measurement, anterior chamber and lens thickness, keratometry and intraocular lens power, refractive index and shape factor for the pseudophakic eye. Comparing the magnification of both eyes of one individual yields aniseikonia, while comparing the preoperative and postoperative situation of one eye provides the gain or loss in ocular magnification. The applicability of this strategy is shown using a clinical example and a small case series in 78 eyes of 39 patients before and after cataract surgery. RESULTS: For the phakic eye, the refractive index of the crystalline lens was adjusted to balance the optical system. The pseudophakic eye is fully determined and we proposed three strategies for considering a potential mismatch of the data: (A) with spherical equivalent refraction, (B) with intraocular lens power and (C) with the shape factor of the lens. Magnification in the phakic eye was -0.00319 ± 0.00014 and with (A) was -0.00327 ± 0.00013, with (B) was -0.00323 ± 0.00014 and with (C) was -0.00326 ± 0.00013. With A/B/C, the magnification of the pseudophakic eye was on average 2.52 ± 2.83%/1.31 ± 2.84%/2.14 ± 2.80% larger compared with the phakic eye. Magnification changes were within a range of ±10%. CONCLUSIONS: On average, ocular magnification does not change greatly after cataract surgery with implantation of an artificial lens, but in some cases, the change could be up to ±10%. If the changes are not consistent between the left and right eyes, then this could lead to post-cataract aniseikonia.

The Burden of Macular Diseases in Central and Eastern Europe-Implications for Healthcare Systems.

BACKGROUND: Despite the significant impact of retinal diseases such as wet age-related macular degeneration (wAMD) and diabetic macular edema (DME), there is a limited understanding of how these conditions are managed in Central and Eastern Europe (CEE). OBJECTIVES: To provide a comprehensive overview of the clinical and economic burden of wAMD and DME in CEE and the status quo associated with their management. METHODS: A narrative literature review was undertaken to identify existing data on wAMD and DME, including epidemiology, economic burden, clinical guidelines, and available and reimbursed treatments. Data were collected from relevant sources such as PubMed, ophthalmology associations, national statistical offices, and government agency websites; practical viewpoints were provided by local ophthalmologists and healthcare economics experts in CEE. RESULTS: Epidemiological data on wAMD and DME are limited in CEE, and intercountry comparison is difficult because of differences in data collection methodologies. There are effective treatment options for wAMD and DME, and international guidelines advocate the use of intravitreal anti-vascular endothelial growth factor injections as first-line therapy. Local expert organizations broadly support these recommendations; nevertheless, no clinical practice guidelines exist on the treatment of wAMD and DME in CEE. Access to and reimbursement of anti-vascular endothelial growth factor agents vary significantly in the region and, as a result, many patients remain untreated or inadequately treated. CONCLUSIONS: There is an urgent need for the creation of a wAMD/DME treatment program in CEE to ensure that patients have timely access to the most appropriate treatments.