Dry Eye Research in 2024: 35 Notable Human Studies

The 2024 picture

What the research shows

The 2024 studies illustrate both progress and uncertainty. Some interventions improved ocular-surface signs without a matching symptom result; a carefully controlled omega-3 trial found no added symptom benefit; and other promising treatments were tested over only weeks or without a comparator. Larger datasets described burden and subtype patterns, while new biomarkers and imaging methods still require external validation.

Treatment trials and follow-up

Many 2024 papers report both symptom and sign outcomes. When those diverge, the summary below states both rather than treating one favorable result as overall success.

1. Laughter exercises compared with lubricant drops

   A noninferiority trial randomized 299 adults aged 18 to 45 with symptomatic dry eye to daily laughter exercises or 0.1% sodium hyaluronate drops for eight weeks. Symptom improvement met the trial's prespecified noninferiority margin, and tear breakup favored exercises; most other outcomes did not differ. Participants knew their assignment, and the result applies to the selected younger group with limited staining.

2. Water-free cyclosporine: staining improved, dryness did not clearly differ

   A double-masked phase 3 trial in China randomized 206 patients to water-free 0.1% cyclosporine or vehicle for 29 days. Corneal staining improved more with cyclosporine, but the between-group difference in the co-primary dryness score was not significant. The short masked period supports a surface effect without proving a matching early symptom benefit.

3. Omega-3 for gland-related dry eye

   A double-masked multicenter trial assigned 132 patients with dry eye and meibomian gland dysfunction to re-esterified triglyceride omega-3 or grape-seed oil. OSDI symptoms improved in both arms, with no significant difference at six or 12 weeks, the primary assessment. The study offers no evidence of added short-term symptom benefit for this formulation and dose.

4. Cenegermin in a dose-ranging dry-eye trial

   A phase 2 double-masked trial compared two cenegermin schedules with vehicle in moderate to severe dry eye. Neither active schedule met the prespecified primary endpoint of greater mean Schirmer improvement at four weeks; one dose had a higher responder rate and the other improved symptoms. The mixed results require confirmation before extending this drug's role beyond its established indications.

5. One-year safety follow-up of water-free cyclosporine

   The ESSENCE-2 open-label extension followed 202 patients on water-free cyclosporine for up to 52 weeks; 175 completed the year. Staining, tear production, and symptoms improved from extension baseline, while instillation-site pain was the most common ocular adverse event. With all participants receiving active drops, these later changes are descriptive rather than a controlled efficacy comparison.

6. Platelet-rich plasma against autologous serum

   A double-masked noninferiority trial randomized 96 adults with moderate to severe dry eye to undiluted platelet-rich plasma or autologous serum drops for four weeks. Symptom improvement with plasma met the stated noninferiority margin, and staining and other measured outcomes did not clearly differ. The result establishes short-term comparability within that margin, not superiority or long-term equivalence.

7. Amniotic membrane under a bandage lens

   A randomized study assigned 93 patients with moderate to severe dry eye to one week of dehydrated amniotic membrane under a specialized bandage lens or the lens alone, then followed them for six months. Symptoms improved substantially in the membrane group; both groups had less staining. The abstract emphasizes within-group gains, so the size of the added membrane effect requires careful reading of the direct comparison.

8. Rebamipide versus hyaluronate for screen-associated dry eye

   A double-masked randomized study treated 28 patients with screen-associated dry eye using 2% rebamipide or 0.1% sodium hyaluronate for four weeks. Both groups improved on symptoms and tear breakup, while corneal staining improved more with rebamipide. The patient-level sample was small even though both eyes were measured.

9. Cyclosporine plus hyaluronate for post-surgery pain

   Thirty patients with persistent post-refractive-surgery dry eye and ocular pain used topical cyclosporine plus sodium hyaluronate for three months. Symptoms, pain ratings, staining, and several tear measures improved from baseline. With no concurrent control or comparison with either ingredient alone, the combination's specific contribution remains uncertain.

10. Hyaluronate drops after cataract surgery

    A clinical comparison followed 84 cataract patients who either added sodium hyaluronate to standard postoperative drops or received standard drops alone. At one month, tear breakup, Schirmer, staining, and corneal epithelial-thickness measures favored the hyaluronate group. Assignment was not described as randomized in the abstract, which limits confidence in a causal treatment effect.

11. Varenicline nasal spray in a Chinese phase 3 trial

    A 20-site, double-masked trial randomized 340 patients in China to varenicline nasal spray or vehicle. At four weeks, more active-treatment patients achieved a substantial Schirmer tear-production response, but the groups did not differ significantly on the eye-dryness symptom score. Sneezing was common, and the short trial supports a tear-production effect more clearly than symptom relief.

12. A dexamethasone insert for aqueous-deficient dry eye

    In a double-masked trial, 75 patients received a slow-release dexamethasone insert in one eye and a sham collagen plug in the other. Staining improved more in insert-treated eyes at four weeks, but patient-reported symptoms did not significantly differ, and eye-pressure elevations were more frequent with steroid treatment. Six weeks of follow-up in selected patients leave longer-term safety and benefit uncertain.

13. Light therapy around cataract surgery

    A randomized trial tested low-level light therapy before and after cataract surgery against sham treatment; 131 of 153 enrolled patients completed follow-up. At one month, treated patients had lower dry-eye symptom scores and longer noninvasive tear breakup. The result is specific to the perioperative setting, with limited follow-up for persistence or later dry-eye outcomes.

14. One-year perfluorohexyloctane follow-up from GOBI

    The KALAHARI extension followed 208 completers from the earlier GOBI trial, all using perfluorohexyloctane drops for up to one year. Sign and symptom gains were maintained among those originally assigned active drops, while former saline recipients improved after switching; reported ocular adverse events were mostly mild or moderate. These are reused, selected GOBI participants in an open-label extension, with no concurrent masked control.

15. TearCare after cyclosporine in the SAHARA extension

    In a crossover extension of SAHARA, 161 participants who had received cyclosporine for six months switched to a TearCare procedure and were followed for another six months. Gland secretion and tear breakup improved after the switch, while the later symptom change from crossover was not statistically clear. This reuses the original SAHARA cohort and lacks a group continuing cyclosporine, so it cannot prove switching is superior.

Population patterns and patient experience

Cross-sectional and administrative data can reveal scale and associations. Their disease definitions, selection, and access to care differ, so the estimates should be read within each study.

16. Data-driven dry-eye subtype rules

    In 261 UK residents, researchers combined gland images, lipid appearance, tear meniscus, and evaporation to propose cutoffs for aqueous-deficient and evaporative dry eye. Evaporative features predominated among diagnosed cases, while some remained unclassified. The derived thresholds need independent validation before they become general diagnostic rules.

17. Screen use in Indian schoolchildren

    A cross-sectional study examined 462 children from two private schools in Ahmedabad and surveyed their device use. Longer daily screen time, especially computer use, was associated with more severe dry-eye measures. The selected schools, self-reported exposure, and observational design do not support a universal screen-time cutoff or prove causation.

18. Systemic medicines and severity in DREAM

    A secondary analysis of 535 DREAM participants compared reported systemic medication use with dry-eye signs and symptoms. Antihistamine use tracked more symptoms and shorter tear breakup; some other drug categories had differing associations. Underlying illnesses and reasons for prescriptions may explain part of the pattern, so these results should not prompt medication changes on their own.

19. Dry-eye measurements across 217 Chinese clinics

    A multicenter cross-sectional study assessed 50,280 clinic visitors across 25 provinces. Using tear breakup under ten seconds as its defining rule, it classified 81.6% as dry eye and identified associations with age, screen exposure, and other factors. That unusually high percentage reflects a single-test, clinic-based definition rather than confirmed disease prevalence in all Chinese adults.

20. Dry-eye symptoms and quality of life in China

    A nationwide cross-sectional survey of 21,916 Chinese residents paired a brief dry-eye symptom score with a general health questionnaire. Greater symptom severity was associated with lower health utility and more pain, anxiety, and activity problems. The simultaneous self-reports cannot show that dry eye caused every health difference.

21. Air pollution and dry-eye outpatient visits

    A time-series analysis related ambient pollution to visits among 5,204 dry-eye patients in Zhengzhou, China. Higher levels of several pollutants tracked more outpatient visits, with differences by season and demographic group. Regional exposure and health-care use are indirect measures, and the associations do not show an individual patient's cause.

22. Why Sjögren symptoms and staining can diverge

    A cross-sectional analysis of 3,455 participants in the Sjögren's International Collaborative Clinical Alliance modeled the gap between symptom scores and ocular staining. Medication use, medical history, quality of life, and demographics accounted for part of that gap. The model is based on this selected cohort and cannot predict an individual's clinical needs without validation.

23. Dry-eye care use over five years

    A Chinese health-record analysis counted 369,755 dry-eye outpatient visits from 145,712 patients between 2017 and 2021. Recorded visits rose 53%, with a larger share handled in primary care. Rising use reflects diagnosis and access as well as possible disease burden; it is not a direct measure of new dry-eye cases.

24. A genetic risk score for dry eye

    A Taiwan Biobank case-control analysis used more than 40,000 participants to search for genetic associations and build a polygenic risk score. Some loci were associated with dry eye, but the combined prediction model had only modest discrimination after clinical covariates were included. The score is a research finding, not a clinical screening test.

25. Sleep quality and ocular symptoms

    A cross-sectional study of 141 veterans linked worse sleep disturbance with greater dry-eye and ocular-pain symptoms; links with objective signs were weaker. The predominantly clinic-based sample and simultaneous questionnaires cannot determine whether poor sleep worsened eye symptoms or the reverse.

Glands, nerves, inflammation, and measurement

The studies below explore new markers and the reliability of existing tests. Most offer associations or method comparisons, not independently validated diagnoses.

26. Meibum lipids change with gland-disease severity

    Nuclear magnetic resonance spectroscopy analyzed meibum from 62 adults spanning no, mild to moderate, and severe gland dysfunction. Several lipid components and hydrocarbon unsaturation fell as disease severity rose, while chain length did not change clearly. The exploratory, cross-sectional sample identifies candidate mechanisms rather than a usable clinical cutoff.

27. Conjunctival mucins vary by location

    Impression cytology compared mucin expression across conjunctival regions in small dry-eye and control groups. Several membrane-associated mucins had different regional patterns, with higher MUC4 and MUC16 in selected dry-eye regions. The small groups and multiple sampling sites caution against treating one region's result as a whole-eye biomarker.

28. Confocal corneal nerves in dry eye and neuropathic pain

    An image-analysis study compared confocal scans from patients with dry eye, neuropathic corneal pain, and controls. Both patient groups had lower nerve area density than controls; nerve junctions were especially reduced in the pain group, while immune-cell density was higher in dry eye. These group differences need prospective validation before classifying individual patients.

29. Ocular-surface screening before cataract surgery

    A prospective single-center screen of 120 cataract candidates without a prior dry-eye diagnosis found abnormal tear or gland measurements in many; 55% met the study's symptom-and-sign diagnostic rule. The selected older surgical group shows why preoperative assessment can matter, but its thresholds and prevalence may not transfer to other clinics.

30. Culture and sequencing of ocular bacteria

    Researchers collected conjunctival samples from 61 people with dry eye and 30 controls, comparing bacterial culture with DNA sequencing. The methods revealed overlapping but distinct community information, and a few bacterial groups were associated with severe dry eye. Sampling and analytic choices can strongly affect low-biomass eye specimens, so clinical interpretation remains unsettled.

31. Tear inflammation during dupilumab treatment

    A prospective tear-protein study compared atopic-dermatitis patients with and without dupilumab-associated ocular-surface disease before and during treatment. Patients who developed ocular problems showed a shift toward a Th1/Th17 inflammatory pattern and more remodeling markers. The observed immune signature is associated with the complication but does not establish a predictive clinical test.

32. AI-assisted meibography across real-world images

    An imaging-method study trained automated eyelid and tarsal-plate segmentation on gland photographs, then evaluated images from 399 dry-eye and 235 comparison subjects. The workflow improved standardization and reported about 81% image-level classification accuracy. Results still depend on image quality and dataset selection; clinical benefit is untested.

33. Two instruments gave different tear-breakup times

    A method-comparison study measured 108 adults with two noninvasive tear analyzers in random order. Tear meniscus height agreed reasonably, but first and average tear-breakup times differed enough that the devices were not interchangeable. The practical lesson is to keep equipment and method consistent when monitoring change.

34. More precise grading of corneal staining

    Twenty-eight eye-care practitioners graded 20 images of Sjögren corneal staining twice using several scoring schemes. Half-step Oxford grades slightly improved repeatability, while dividing the cornea into regions increased variability. This image-based method study informs trial scoring but does not show that finer grades improve patient outcomes.

35. Bilateral nerve effects after one-eye refractive surgery

    A prospective study followed 34 patients after unilateral SMILE or surface laser surgery and examined nerves, tear function, and symptoms in both eyes. Nerve and sensitivity changes were observed bilaterally, suggesting effects beyond the treated eye. The small nonrandomized procedure groups need confirmation before drawing firm conclusions about mechanism or long-term dry-eye risk.