Evaluation of Dry Eye After Refractive Surgery According to Preoperative Meibomian Gland Status

Influential Signs of Dry Eye-Related Ocular Symptoms in Participants With Unstable Tear Film

PURPOSE

The aim of this study was to investigate the factors influencing dry eye disease (DED)-related ocular symptoms in participants with short fluorescein tear break-up time (FTBUT).

METHODS

This cross-sectional study included 82 participants with short FTBUT (<10 seconds). Examinations included Ocular Surface Disease Index (OSDI), FTBUT, average noninvasive tear break-up time (NIBUTave), lid wiper epitheliopathy, lipid layer thickness, blink rate, partial blink, tear meniscus height, and meibomian gland (MG) evaluation which included ratio of residual MG area (RMGA) and MG grade in tarsal plates. One-way analysis of variance was used to detect differences between symptomatic tear film instability group (FTBUT <5 s, OSDI ≥13), asymptomatic tear film instability group (FTBUT <5 s, OSDI <13), and control group (FTBUT ≥5 s, OSDI <13). A bivariate correlation, partial correlation, and multiple linear regression analyses were used to identify major factors. Only the right eye was included.

RESULTS

Among the participants with FTBUT <5 seconds, symptomatic group showed less upper RMGA ( P < 0.001) and NIBUTave ( P = 0.010). OSDI was negatively associated with upper RMGA ( r = -0.450, P < 0.001) and NIBUTave ( r = -0.414, P = 0.001), and positively associated with upper MG grade ( r = 0.277, P = 0.027). Linear regression analysis showed that the upper RMGA significantly affected OSDI (B = -41.895, P = 0.001), while not significantly correlated with age, upper MG grade, and NIBUTave.

CONCLUSIONS

The upper RMGA might be the main factor affecting DED-related discomfort in participants with unstable tear film, indicating an early ocular change in DED.

Post-refractive Surgery Dry Eye: A Systematic Review Exploring Pathophysiology, Risk Factors, and Novel Management Strategies

Dry eye disease frequently manifests following corneal refractive procedures, significantly impacting patients' quality of life. This review systematically synthesizes current evidence on the pathophysiological mechanisms, risk factors, and therapeutic interventions for post-refractive surgery dry eye. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, a systematic review of literature published until August 2023 was conducted, focusing on post-refractive surgery dry eye. Eighteen relevant studies were identified through screening and eligibility assessment. A qualitative synthesis of outcomes was performed using narrative and thematic analysis methods. Surgically induced neurotrophic deficiency, stemming from nerve transection, triggers a cascade of events including apoptosis, inflammation, and lacrimal dysfunction, ultimately leading to tear film instability. Risk factors such as female gender, thyroid eye disease, meibomian gland dysfunction, higher ablation depths, and the use of LASIK over surface ablation exacerbate the condition. While conventional treatments like artificial tears provide temporary relief, emerging interventions such as nerve growth factors, matrix metalloproteinase inhibitors, serum eye drops, and specialized contact lenses show promise in promoting nerve regeneration and epithelial healing. Strategies such as customized ablation profiles, smaller optical zones, and nerve-sparing techniques like small incision lenticule extraction demonstrate potential advantages. A multifaceted therapeutic approach targeting neuroprotection, anti-inflammatory mechanisms, and tear film stabilization is imperative for effectively managing post-refractive surgery dry eye. Future research should focus on evaluating prognostic biomarkers, exploring precision medicine approaches, and investigating neuroprotective adjuvants to further enhance treatment outcomes.

Changes of dry eye parameters after small incision lenticule extraction surgery in patients with different ocular surface disease index scores

To evaluate the changes of dry eye parameters after small incision lenticule extraction (SMILE) surgery in patients with different ocular surface disease index (OSDI) scores. Prospective research. Participants were divided into two groups: Group A, OSDI < 13; and Group B, OSDI ≥ 13. The OSDI scores, tear meniscus height (TMH), first non-invasive tear film break-up time (NIBUT-First), and meibomian gland loss (MGL, %) were recorded at postoperative 1 -week and 1-month.113 eyes (57 patients) were enrolled, 70 eyes in Group A, and 43 eyes in Group B. In Group A, the OSDI scores significantly increased at 1-week and 1-month postoperative (all P < 0.001); the TMH, NIBUT-First and lipid layer grade significantly decreased at postoperative 1-week (P = 0.003, 0.005, 0.007, 0.004, respectively), but returned to preoperative level at 1-month postoperative. In Group B, only the lipid layer grade significantly decreased at postoperative 1-week (P < 0.05). Patients with different preoperative OSDI scores may experience different changes early after SMILE surgery. Patients with OSDI scores < 13 may experience more dramatic changes in dry eye symptoms which would resolve, while subjective complains could still exists at 1 month after surgery.

Changes of Subjective Symptoms and Tear Film Biomarkers following Femto-LASIK

Femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) represents a common treatment modality in refractive surgery and shows excellent results in terms of safety, efficacy, predictability, and long-term stability. However, patients may be affected by dry eye symptoms. The aim of this study was to identify a potential association between subjective dry eye symptoms, objective dry eye markers, and possible changes in the tear film, which could be a target for future therapy development. Therefore, clinical (dry eye) examinations (OSDI, Schirmer test, lissamine green and fluorescein staining, BUT, visual acuity) were carried out before LASIK as well as 5 and 90 days post-OP. The dry eye marker MMP-9, cytokines (IL-1β, IL-8), and pain markers (NGF, CGRP) were quantified in tear samples with immunoassays. In addition, correlation analyses were performed. Clinical examinations revealed an upregulated OSDI score 5 days post-OP and an increased lissamine green staining score 90 days post-OP. Downregulated CGRP levels were noted 5 days post-OP, while other protein markers were not significantly altered after Femto-LASIK. Hence, Femto-LASIK surgery induced subjective symptoms like that of dry eye which could objectively rather be classified as Femto-LASIK-related discomfort. In the future, this could possibly be better detected and treated using pain markers such as CGRP.