Design and Baseline Characteristics of the HELP Study: An Extended and Long-Term Observation of Pathological Myopia in Caucasians.

PURPOSE: To assess the natural disease progression of high myopia in Caucasians considered at risk for the development of myopic choroidal neovascularization (mCNV).

METHODS: Subjects were recruited in 25 clinical sites between June 2014 and June 2016. Main inclusion criteria included axial length of ≥26 mm, best-corrected visual acuity ≥0.05 decimal equivalent and presence of at least one out of five predefined morphological disease risk criteria. These were (1) subfoveal choroidal thinning < 50 µm, (2) enhanced choroidal curvature length > 6,300 µm, (3) lacquer cracks, (4) patchy atrophy > 5 mm2 and (5) preexisting mCNV in the fellow eye (German Clinical Trial Register DRKS00007761).

RESULTS: A total of 150 participants (66% females) with a mean age of 57.2 (±12.7) years (range 21.9-86.2 years) were included. The disease criteria most frequently encountered were choroidal thinning (33.3%) and lacquer cracks (32.7%). Enhanced choroidal curvature length was detected in only 8 subjects and always occurred in combination with other disease criteria. Presence of patchy atrophy was found to be more common in older subjects (p = 0.0012) and also associated with a more severe disease manifestation.

CONCLUSION: The baseline data of this study indicate that enhanced choroidal curvature might be less common in Caucasians than in Asian populations. Further, disease severity in patients with high myopia is relatively high in the presence of patchy atrophy.