Impact of corneal refractive surgery on the precorneal tear film

Efficacy of 0.05% cyclosporine A on tear inflammatory cytokines and goblet cell function after corneal refractive surgery

BACKGROUND

Corneal refractive surgeries offer rapid vision correction, while dry eye disease remains a common postoperative complication that significantly impacts patients' quality of life. The etiology of postoperative dry eye is multifactorial. Cyclosporine A (CsA) has been employed in the treatment of dry eye due to its ability to suppress T cell-mediated immune responses and reduce inflammation. The present study was designed to assess the early effect of 0.05% cyclosporine A (CsA) eye drops on tear film stability, ocular surface inflammation and goblet cell function in patients following corneal refractive surgery.

METHODS

One hundred forty-four eyes of 72 participants undergoing corneal refractive surgery were enrolled and randomized into additional 0.05% CsA eye drops treated group or conventional schedule treated group. Ocular Surface Disease Index (OSDI), relevant ocular surface clinical parameters, tear inflammatory cytokine levels, conjunctival impression cytology, and gene expression of Keratin 7 (KRT-7) as well as Mucin5AC (Muc5AC) in conjunctival epithelial cells were measured before surgery (baseline) and at 1 month after surgery. All indicators and their changing value were compared against baseline or across different groups.

RESULTS

0.05% CsA treatment exhibited greater changes in OSDI, NIBUT, LLT and CFS in the early postoperative period (P = 0.004, P = 0.002, P = 0.032, P = 0.008). Compared to control group, there was a more significant decrease in IFN-γ and TNF-α levels in tear fluid in CsA group after surgery (P = 0.012, p = 0.032). Additionally, KRT-7 and IFN-γ showed recovery in conjunctival cells with 0.05% CsA treatment (P = 0.003, P = 0.019). The postoperative KRT-7 and Muc5AC levels were negatively correlated with corresponding IFN-γ levels in tear fluid among all subjects (r = -0.200, p = 0.016; r = -0.229, p = 0.006).

CONCLUSIONS

For patients undergoing refractive surgery, the application of 0.05% CsA suppressed the expression of inflammatory cytokines such as IFN-γ and TNF-α, and preserved goblet cell function. These effects ultimately contribute to maintaining ocular surface stability and alleviating dry eye related symptoms during the early postoperative period following refractive surgery.

The effect of preoperative total antioxidant capacity on short-term outcomes after kerato-lenticule extraction surgery

To evaluate influence of total antioxidant capacity expression (TAC) on outcome of kerato-lenticule extraction (KLEx). A prospective non-randomized trial was conducted and patients received KLEx were categorized via TAC concentration. A total of 56 and 36 eyes were enrolled into the low TAC and high TAC groups. The main outcomes are the postoperative un-corrected visual acuity (UCVA), refraction and superficial keratitis between groups. The generalized liner model was applied for statistical analysis. One month after the KLEx surgery, the UCVA was significantly higher in the high TAC group (P = 0.028), and low TAC group associated with superficial keratitis risk compared to high TAC group (P = 0.035). The trends of TAC and ascorbic acid (AA) decrements were more significant in the low TAC group (both P < 0.05). Low TAC population and old age correlated to poor UCVA (both P < 0.05) while the thick CCT correlated to better UCVA (P = 0.030). Besides, the low TAC population (P = 0.032) correlated to higher superficial keratitis rate, while old age (P = 0.018) correlated to lower superficial keratitis rate. The presence of low TAC expression correlated to worse UCVA and higher risk of superficial keratitis after KLEx.

Is Thermal Pulsation Therapy Effective for Dry Eyes Before and After Cataract Surgery? A Systematic Review and Meta-Analysis

Background

Meibomian gland dysfunction (MGD) is a primary cause of evaporative dry eye disease (DED), which is often exacerbated by cataract surgery due to surgical trauma and inflammation. Thermal pulsation therapy (TPT) aims to enhance meibomian gland function and relieve dry eye symptoms. We conducted a systematic review and meta-analysis to evaluate the effectiveness of TPT in managing dry eye symptoms associated with cataract surgery.

Methods

A systematic search was performed in December 2024 across PubMed, ScienceDirect, CINAHL, and the Cochrane Central Register of Controlled Trials to identify original research on the efficacy of TPT in addressing cataract surgery-related dry eye symptoms. The quality of the included studies was evaluated using the Risk of Bias in Non-Randomized Studies of Interventions tool, with results visualized through the Robvis 2.0 tool developed by the Cochrane Collaboration.

Results

The search yielded 365 records, of which seven studies met the inclusion criteria for this meta-analysis. Key outcomes analyzed included the meibomian gland yielding liquid secretion (MGYLS) score, tear break-up time (TBUT), ocular surface disease index (OSDI) score, and lipid layer thickness (LLT). The meta-analysis revealed a moderate effect of TPT, with a small but clinically significant improvement observed in MGYLS scores (Cohen's d = 0.29, p = 0.033) and TBUT (Cohen's d = 0.15, p = 0.029). However, the effects on OSDI scores and LLT were not statistically significant. Study heterogeneity varied, with some outcomes exhibiting considerable variability.

Conclusion

TPT provides moderate and clinically meaningful improvements in MGYLS scores and TBUT for patients experiencing dry eye symptoms after cataract surgery, although improvements in OSDI scores and LLT did not achieve statistical significance. The variability in study quality and heterogeneity highlights the need for well-designed, high-quality research to confirm these findings and evaluate the durability of TPT's therapeutic effects both before and after cataract surgery.

Effect of posterior chamber phakic refractive lens implantation on the ocular surface and tear film

To evaluate changes in dry eye-related parameters after posterior chamber phakic refractive lens (PC-PRL) implantation. This prospective study included 21 highly myopic patients (39 eyes) who underwent PC-PRL implantation at Lanzhou Huaxia Eye Hospital between January 2021 and June 2022, with a 3-month postoperative follow-up. In addition to routine preoperative examinations, dry eye assessments were conducted preoperatively and at 1 week, 1 month, and 3 months postoperatively. These assessments included the Ocular Surface Disease Index (OSDI) questionnaire score, non-invasive first tear break-up time (NIF-BUT), non-invasive average tear break-up time (NIA-BUT), tear meniscus height (TMH), meibomian gland loss (MGL) rate, and Schirmer I test (SIt). Repeated measures ANOVA was used to compare the differences in parameters across different time points, with pairwise comparisons conducted using the LSD-t test. After grouping, the Student's t-test was applied to compare normally distributed data, while the Mann-Whitney U test was used for non-normally distributed data. Categorical data were analyzed using the chi-square test. A total of 21 patients (39 eyes) were included, comprising 10 males (19 eyes) and 11 females (20 eyes), aged 19 to 49 years (33.76 ± 7.87). All patients completed the 3-month follow-up. Significant differences in OSDI scores were observed pre- and post-surgery (P = 0.008), with a peak at one week post-surgery (P < 0.001), then stabilizing at one and three months post-surgery. Postoperative NIF-BUT and NIA-BUT significantly decreased (P < 0.001 for both) but returned to preoperative levels within three months. There were no significant changes in TMH, MGL, or SIt postoperatively (P > 0.05). Significant differences in dry eye parameters were observed between the dry eye and control groups before and after surgery (P < 0.001). PC-PRL implantation impacts tear film stability on the ocular surface after surgery, leading to varying degrees of dry eye symptoms in patients. After surgery, all dry eye parameters return to their preoperative levels within three months.

Refractive Surgery in Myopic Children

In this paper, we summarize the current knowledge on refractive surgery performed in the myopic pediatric population. We describe the main concerns about refractive surgery in myopic children and the indications for refractive surgery in this age group. We present a range of surgical procedures that are being used for the management of unilateral/bilateral myopia in children: corneal refractive surgery (PRK, LASEK, LASIK, FS-LASIK and SMILE) and intraocular refractive surgery (phakic intraocular lens implantation, refractive lens exchange or clear lens extraction), with both their advantages and drawbacks. We also describe the various complications and measures to prevent them.

Anterior segment inflammation and its association with dry eye parameters following myopic SMILE and FS-LASIK

PURPOSE

To evaluate dry eye and anterior segment inflammation after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and investigate their association.

METHODS

This prospective and observational study included 96 eyes from 48 myopic patients. The evaluation was performed at baseline, postoperative day 1, week 1, month 1 and month 3. Outcome measures included anterior chamber flare, bulbar redness (BR), limbal redness (LR), ocular surface disease index (OSDI), tear meniscus height (TMH), the first and average noninvasive breakup time (NIBUT-1, NIBUT-a), fluorescein breakup time (FBUT), corneal fluorescein staining (CFS), and Schirmer I. Generalized estimating equations (GEEs) were applied to explore the correlation between flare and ocular surface parameters.

RESULTS

Flare increased significantly in both groups at day 1 and week 1 and then returned to baseline at month 1. In both groups, BR decreased on day 1 and then gradually increased towards the baseline. In FS-LASIK, LR was lower than baseline at day 1 and month 3. An increase in OSDI was found in the SMILE group on day 1, and in the FS-LASIK group at day 1 to month 1. NIBUT-1 and NIBUT-a decreased significantly on day 1 in both groups. At month 3, NIBUT-a did not return to baseline in FS-LASIK. CFS increased significantly at week 1 in both groups. All parameters were comparable between SMILE and FS-LASIK except for OSDI and NIBUT-a. Time and spherical equivalent showed a correlation with flare.

CONCLUSIONS

Both SMILE and FS-LASIK induced elevated anterior chamber flare and dry eye. However, flare might not be considered a factor determining perioperative dry eye.Key MessagesDry eye disease is common after corneal refractive surgery. Signs and symptoms of dry eye disease persist longer after FS-LASIK compared with SMILE.Both FS-LASIK and SMILE transiently disrupted blood-aqueous barrier integrity, leading to anterior segment inflammation.Anterior chamber flare might not be considered a factor explaining perioperative dry eye, other biomarkers remain for future exploration.

TFOS Lifestyle Report Executive Summary: A Lifestyle Epidemic - Ocular Surface Disease

The Tear Film & Ocular Surface Society (TFOS) Workshop entitled 'A Lifestyle Epidemic: Ocular Surface Disease' was a global initiative undertaken to establish the direct and indirect impacts of everyday lifestyle choices and challenges on ocular surface health. This article presents an executive summary of the evidence-based conclusions and recommendations of the 10-part TFOS Lifestyle Workshop report. Lifestyle factors described within the report include contact lenses, cosmetics, digital environment, elective medications and procedures, environmental conditions, lifestyle challenges, nutrition, and societal challenges. For each topic area, the current literature was summarized and appraised in a narrative-style review and the answer to a key topic-specific question was sought using systematic review methodology. The TFOS Lifestyle Workshop report was published in its entirety in the April 2023 and July 2023 issues of The Ocular Surface journal. Links to downloadable versions of the document and supplementary material, including report translations, are available on the TFOS website: http://www.TearFilm.org.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

Dry Eye Disease as a Cause of Refractive Errors After Cataract Surgery - A Systematic Review

Dry eye disease (DED) is a multifactorial ocular surface disorder characterized by loss of tear film homeostasis with associated ocular symptoms, like dryness, foreign body sensation, and inflammation. Numerous reports confirm an increase in dry eye symptoms after cataract surgery. DED also significantly disturbs preoperative biometric measurements, mainly by changes in keratometry measurements. The purpose of this study is to evaluate the effect of DED on biometric measurements before cataract surgery and postoperative refractive errors. PubMed database was searched for keywords: cataract surgery, dry eye disease, refractive error, refractive outcomes, keratometry, and biometry. Four clinical studies evaluating the effect of DED on refractive errors were included. In all studies, biometry was performed before and after dry eye treatment, and the mean absolute error was compared. Various substances have been used to treat dry eye, such as cyclosporin A, liftitegrast, and loteprednol. The refractive error was significantly lower after treatment in all studies. The results unanimously indicate that refractive errors can be reduced by proper treatment of DED before cataract surgery.