A Structural Shift in the Readability of Ophthalmology Abstracts in Late 2023

To assess long-term trends in the readability of ophthalmology abstracts and to determine whether a structural change occurred during the study period.

Bibliometric longitudinal analysis.

A total of 198, 201 unique English-language abstracts published between January 2000 and September 2025 in 67 PubMed-indexed ophthalmology journals.

Abstract readability was quantified using the Flesch Reading Ease score. Temporal trends were analyzed using segmented regression with data-driven breakpoint selection. Secondary analyses included additional validated readability indices and linguistic features (including lexical density, lexical diversity, and clause density). Differences before and after the breakpoint were assessed using nonparametric tests.

Changes in abstract readability over time, primarily measured by the Flesch Reading Ease score.

Readability improved gradually from 2000 until 2023, followed by a marked decline thereafter. Segmented regression identified a structural breakpoint in October 2023, after which readability declined sharply, with mean Flesch Reading Ease scores decreasing by -0.222 (95% confidence interval, -0.257 to -0.204) points per month compared with a prebreakpoint increase of +0.008 (95% confidence interval, 0.007‑0.010) points per month (P < 0.001). Readability differed significantly between the pre-October and post-October 2023 periods (median, 30.74 [interquartile range, 30.39-31.06] vs. 28.35 [interquartile range, 27.29-29.54]; P < 0.001). Similar patterns were observed across multiple readability indices. The decline was accompanied by increases in syllables per word, proportion of polysyllabic words, lexical density, lexical diversity, and clause density, whereas words per sentence continued to decrease over time. Findings were consistent across journal impact strata and remained evident in within-author analyses.

In this large longitudinal study of ophthalmology abstracts, readability improved for more than 2 decades before reversing sharply in late 2023. The decline was associated with increased lexical complexity and with indicators of greater syntactic complexity and was observed across journals and author subgroups. Although the causes of this shift cannot be determined from the present data, the findings indicate a meaningful change in the linguistic characteristics of ophthalmology abstracts and underscore the importance of maintaining readability in scientific communication.

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