The Clinical Role of the Choroidal Assessment in High Myopia: Characteristics and Association With Neovascular and Atrophic Complications.

Purpose: To investigate the clinical utility of choroidal quantitative assessment associated with the presence of macular neovascularization (MNV) or atrophy in high myopia. Methods: The study was designed as a retrospective case series with two-year follow-up. We measured choroidal thickness (CT) and the presence and subtype of dome-shaped macula (DSM). In DSM eyes we also calculated the presence and type of choroidal deepening (CD). The eyes were categorized as Subgroup 1 (high myopia without complications), Subgroup 2 (high myopia complicated by MNV), and Subgroup 3 (high myopia complicated by macular or posterior pole atrophy). Main outcome measures were the detection of significant CT cutoffs associated with the three subgroups of eyes and the clinical impact of DSM and CD subtypes. Results: Our cohort (190 eyes affected by high myopia) was categorized as Subgroup 1 (66 eyes), Subgroup 2 (72 eyes) and Subgroup 3 (52 eyes). Baseline CT values allowed to separate the subgroups with myopic-related complications (area under the curve = 0.85; P < 0.05). In Subgroup 1, vertical DSM was the most frequent (54%), with CD absence characterizing the 46% of cases. Round DSM was the most represented subtype in Subgroup 2 (49%), with 55% of sub-dome CD subtypes; in these cases, MNV resulted always localized in the fovea. Subgroup 3 equally shown horizontal or vertical DSM (53% and 47%, respectively), with 80% of cases showing peri-dome CD. Conclusions: Choroidal quantitative assessment can categorize three high myopia subgroups. MNV subgroup is characterized by intermediate choroidal thinning and higher prevalence of round DSM with sub-dome CD.