A meta-analysis of case–control studies has found a significant association between diabetes and dry eye syndrome, with a pooled odds ratio of approximately 1.3.1 As well, individual surveys report considerably higher relative prevalence of dry eye and MGD in diabetic populations. For example, a nationwide Saudi survey, using the Ocular Surface Disease Index (OSDI), found that just over half of diabetic respondents met criteria for dry eye disease.2

These figures likely under-represent true prevalence, given that many diabetic patients experience reduced corneal sensitivity and, therefore, exhibit clinical signs without corresponding symptoms.3 MGD, formally defined by international consensus as a chronic, diffuse abnormality of the meibomian glands typically resulting in altered secretion and consequent tear film instability, is the single most common cause of this evaporative pattern of disease and is disproportionately represented in diabetic cohorts.4

WHY THE DIABETIC OCULAR SURFACE IS DIFFERENT

Diabetic dry eye is rarely explained by a single mechanism. Instead, it reflects the convergence of several diabetes-related processes acting simultaneously on the lacrimal functional unit.

Microvascular Compromise and Autonomic Neuropathy

Chronic hyperglycaemia damages small-calibre vessels throughout the body, and the lacrimal gland is not spared. Hyperglycaemia-driven microvascular damage to the lacrimal gland, together with diabetic autonomic neuropathy affecting lacrimal innervation, both contribute to diminished aqueous tear production, compounding any evaporative component already present.5 Tear secretion, meibum expression, and blinking are all, at least in part, under parasympathetic control, so this autonomic component is of particular clinical relevance – it is discussed further in the context of intense pulsed light’s proposed neurostimulatory mechanism below.

Corneal Neuropathy and Reduced Sensitivity

The cornea is among the most densely innervated tissues in the body, and diabetic peripheral neuropathy (DPN) frequently manifests there before it is clinically obvious elsewhere. A prospective study published in Diabetes Care found a significant association between DPN and dry eye disease in diabetic patients, reinforcing that neuropathy – not only microvascular disease – is a meaningful independent contributor to ocular surface disruption.6 This relationship was corroborated in a more recent, larger cross-sectional study of 158 eyes from 79 patients with type 2 diabetes, which found that those with confirmed DPN had significantly reduced corneal sensitivity and significantly higher OSDI scores than those without DPN, alongside a negative correlation between corneal sensitivity and tear osmolarity.3 This loss of corneal nerve density blunts the sensory feedback loop that would normally drive reflex tearing and blinking. Critically, this sensory deficit means that the severity of a diabetic patient’s signs and their reported symptoms frequently diverge – patients may have advanced ocular surface disease while reporting comparatively mild discomfort.3

Meibomian Gland Structural and Cellular Change

At the cellular level, in-vitro work has demonstrated that while insulin appears to support proliferation of human meibomian gland epithelial cells, sustained high glucose concentrations are directly cytotoxic to these same cells, offering a plausible mechanistic explanation for gland loss that tracks with glycaemic control.7 Clinically, a comparative study of patients with type 2 diabetes found meibography scores were significantly higher (indicating greater gland dropout) and the number of expressible glands significantly lower in the diabetic group than in matched non-diabetic controls.8 Objective assessment of gland structure and secretion quality – meibography, expressibility grading, and meibum quality scoring, as codified by international consensus diagnostic criteria – allows these changes to be quantified and tracked over time in clinical practice.9

Inflammatory Load and the Mixed-Mechanism Picture

Hyperglycaemia promotes low-grade chronic inflammation and oxidative stress at the ocular surface, and diabetes-associated dry eye has been consistently linked with tear film instability, meibomian gland changes, and broader disruption of the lacrimal functional unit through combined metabolic, neuropathic, and inflammatory pathways acting together.10 This is consistent with the broader pathophysiological model of dry eye disease as a self-perpetuating cycle of tear film instability, hyperosmolarity, and ocular surface inflammation described in the Tear Film and Ocular Surface Society Dry Eye Workshop II (TFOS DEWS II) Pathophysiology report.11 Taken as a whole, diabetic dry eye should be understood as a mixed-mechanism disease with evaporative, aqueous-deficient, neurogenic, and inflammatory contributors operating simultaneously – a picture that has clear parallels with the staged, mixed-mechanism presentations increasingly recognised in post-surgical dry eye and formalised in the TFOS DEWS III framework.12,13

THE CASE FOR PROACTIVE MANAGEMENT

Two features of diabetic dry eye argue strongly for a proactive, screening-based approach rather than a purely reactive one.

Symptoms are an unreliable early warning system. As noted above, corneal hypoaesthesia means a patient may have significant gland dropout, an unstable tear film, and surface staining while reporting minimal discomfort, particularly once neuropathy has become established.3 Waiting for symptomatic presentation risks missing a substantial proportion of affected patients, and risks intervening only once gland architecture has already been lost – a change that, unlike gland function, is not reliably reversible.

TearStim intense regulated pulsed light in use.

The trajectory is progressive. Several studies report a relationship between the duration of diabetes and both tear film instability and meibomian gland loss.8,10 Given that diabetic retinopathy screening already brings this patient group into optometric and ophthalmic clinics on a scheduled basis, that same visit represents a natural and efficient opportunity to incorporate objective, non-invasive ocular surface assessment – tear break-up time, meibography, lid margin evaluation, and osmolarity or inflammatory marker testing – before symptoms drive the patient to seek help elsewhere. Early identification and early intervention, targeting gland function while it can still be modulated, is likely to yield better long-term outcomes than intervention once irreversible gland dropout has occurred.

This rationale mirrors current thinking in the broader dry eye literature: the TFOS DEWS III Diagnostic Methodology report emphasises identifying the dominant pathophysiological subtype early and matching therapy to it,12 while staged escalation as the clinical picture evolves has been demonstrated directly in a recent case report of post-surgical mixed-mechanism dry eye.13 Conventional first-line management of MGD – warm compresses, lid hygiene and, where indicated, omega-3 supplementation – remains an appropriate foundation of care,14 but compliance with these self-administered measures is notoriously poor. This is part of what makes an in-clinic, practitioner-delivered physical therapy such as IPL such an attractive adjunct for diabetic patients, where an evaporative, MGD-driven component is so often present alongside neurogenic and aqueous-deficient elements: it points toward including IPL as part of the initial management plan, rather than reserving it for treatment-resistant cases.

IPL AND THE MEIBOMIAN GLAND: FROM DERMATOLOGY TO DRY EYE

Intense pulsed light was developed initially as a dermatological tool. Polychromatic, high-intensity flashlamp devices were first used in the late 20th century to manage vascular skin lesions and hypertrichosis, exploiting the principle of selective photothermolysis, whereby pulsed light energy is preferentially absorbed by pigmented chromophores such as haemoglobin and melanin, and converted to heat.15 The link to dry eye management emerged serendipitously: clinicians treating facial rosacea with IPL began to notice that patients’ concurrent dry eye symptoms improved alongside their skin.15 This prompted the development of periocular IPL protocols and, eventually, dedicated ophthalmic devices designed and certified specifically for treating MGD – a lineage that leads directly to devices including the TearStim platform in use today. TearStim and its predecessor E>Eye, using intense regulated pulsed light (IRPL), were developed, specifically engineered, and calibrated for periocular use and dry eye treatment.

The Foundational Randomised Trial

The first prospective, randomised, double-masked, placebo-controlled paired-eye trial of periocular IPL for MGD was published in 2015, using the E>Eye IRPL platform – the same underlying regulated-pulse technology now used in the current-generation TearStim system. In this study, 28 participants received IPL to one eye with sham treatment to the fellow eye across three sessions over 45 days. The treated eye showed statistically significant improvement in lipid layer grade and noninvasive tear break-up time compared with baseline and with the control eye, alongside a modest but significant reduction in subjective symptom scores, while tear evaporation rate and osmolarity were unchanged.16 The authors proposed heat-mediated softening of meibum, reduced vascularity and inflammation, and possible antibacterial effects as candidate mechanisms.

Independent Replication in Randomised Trials

Findings from the 2015 trial have since been replicated in independent randomised, controlled designs conducted by unrelated research groups using different IPL platforms, considerably strengthening confidence in the underlying effect. A sham-controlled, double-masked trial from Thailand found that active IPL treatment produced significantly greater improvement in meibomian gland function and tear film parameters than sham treatment in patients with MGD.17 A separate United States-based randomised controlled study similarly found that active IPL significantly improved both signs and symptoms of dry eye disease due to MGD relative to a sham comparator.18 Taken together with the New Zealand (NZ) trial discussed below, at least four independently conducted randomised controlled trials now support the efficacy of periocular IPL for MGD – an unusually strong evidence base for a physical, device-based dry eye therapy.

A Cumulative-Dose Randomised Trial

A follow-up randomised, double-masked, placebo-controlled trial by an overlapping group of investigators in NZ – again using the E>Eye IRPL platform – extended this work considerably, enrolling 87 participants over a 15-week period and directly comparing four-flash and five-flash IPL protocols against sham treatment.19 Both active treatment arms achieved statistically significant reductions in three validated symptom instruments (OSDI, Standard Patient Evaluation of Eye Dryness (SPEED), and Symptom Assessment in Dry Eye (SANDE)). There was also significant improvement in tear film lipid layer grade and meibomian gland capping relative to placebo, together with measurable inhibition of Corynebacterium macginleyi growth on eyelid margin swabs – a finding consistent with a proposed antimicrobial contribution to the treatment effect.19 Notably, the five-flash protocol, which adds a pulse positioned temporally adjacent to the lateral canthus, produced earlier and more consistently sustained improvements than the four-flash protocol. The authors explicitly raised possible neuromodulatory stimulation of the parasympathetic innervation of the meibomian glands, arising from the pterygopalatine ganglion, as a candidate explanation for this additional benefit.19,20 Independent, peer-reviewed support for the neurostimulation hypothesis is discussed further below. This trial also confirmed that benefits are genuinely cumulative rather than immediate: reliable, sustained improvement was only established from around the third to fourth treatment onward, reinforcing that a full course, rather than a single session, is required before treatment efficacy can be fairly judged in an individual patient.

Replication Across the Evidence Base

Since the original 2015 trial, further peer-reviewed studies using a range of devices – many of them using the same E>Eye platform that underlies TearStim – have replicated meaningful improvements across objective measures such as tear break-up time, meibomian gland yield, and objective optical quality, alongside consistent gains in patient-reported symptom scores. An Australian study found significant improvement in meibomian gland expressibility and symptom scores in patients with moderate-to-advanced MGD following IPL and gland expression.21 An Italian prospective study using a comprehensive ocular surface workup found significant improvements in non-invasive break-up time and lipid layer thickness following a course of IRPL.22 A Turkish case series using the E>Eye device found that patients with moderate-to-severe acute blepharitis or blepharoconjunctivitis achieved significant improvement in signs, symptoms, and meibomian gland morphology following IPL.23 A French study using the E>Eye device in patients with severe, treatment-refractory MGD-related dry eye similarly reported significant symptomatic and objective improvement with a good safety profile.24 An earlier Chinese open-label study using the same platform confirmed both the safety and effectiveness of the approach in a general MGD population.25 Most recently, a 2024 study analysing temporal changes in tear film stability between IPL sessions provided further mechanistic detail on how improvement accrues across a treatment course.26 Further studies using other commercial IPL platforms have reported comparable improvements in meibomian gland yield27 and objective optical quality.28 Collectively, this body of work – spanning NZ, Australia, Italy, Turkey, France, China, Korea, and Japan – has established IPL, and periocular IRPL specifically, as a credible, well-evidenced physical therapy for evaporative dry eye secondary to MGD, distinct from – and complementary to – pharmaceutical approaches.

BEYOND HEAT: THE NEUROSTIMULATION HYPOTHESIS

While early explanations of IPL’s benefit centred on thermal softening of meibum and reduction of lid margin vascularity and inflammation, more recent commentary has proposed an additional, complementary mechanism that is particularly relevant to a diabetic cohort: neurostimulation of the parasympathetic pathways supplying the periocular glands.

The TearStim intense regulated pulsed light device.

The proposed model works as follows. TearStim and other regulated-pulse IPL devices deliver a structured train of sub-pulses of differing wavelength within each flash – shorter, longer-wavelength components that penetrate more deeply alongside brief, higher-energy components absorbed more superficially. This patterned energy delivery is theorised to generate a transient micro-gradient of temperature across the myelin sheath of nerve fibres running through the treated zygomatic and bulb-orbital regions, corresponding anatomically to branches of the parasympathetic supply that ultimately innervate the lacrimal and meibomian glands.15 The proposal is that this thermal micro-gradient triggers local release of neurotransmitters (acetylcholine) at the postganglionic level, exciting the parasympathetic pathway and thereby prompting increased tear and meibum secretion, in addition to any direct thermal or photobiomodulatory effect on the glands themselves.15

This hypothesis, while requiring further independent physiological validation, is conceptually attractive in the diabetic context specifically because autonomic neuropathy – the same process implicated in diminished lacrimal and meibomian output in diabetes – is fundamentally a parasympathetic signalling deficit.5 Independent support for this idea comes from the anatomical work of LeDoux and colleagues, who mapped parasympathetic innervation of the meibomian glands via the pterygopalatine ganglion in an animal model,20 and from the randomised trial discussed above, whose authors explicitly proposed neuromodulatory stimulation of this same pathway to help explain the superior and earlier treatment response observed with an additional, more laterally placed IPL pulse.19 If TearStim’s regulated-pulse light genuinely provides a degree of local neural stimulation to the glands’ parasympathetic supply, it would represent a mechanism that speaks directly to one of the principal drivers of diabetic dry eye, rather than only addressing the downstream consequences of gland obstruction.

Alongside this proposed neurogenic action, the broader mechanistic picture for IPL in MGD is generally described as multifactorial, encompassing:

• Thermal softening of meibum, easing expression through the glands and ducts,

• Photobiomodulation, with proposed stimulation of meibomian gland mitochondrial activity and support for collagen turnover,

• Vascular effects, with selective heating reducing telangiectasia and proinflammatory mediator release,

• Antimicrobial effects, through absorption of light energy by pigmented structures and inhibition of periocular bacterial growth,19 and

• Tissue remodelling, supporting fibroblast and collagen activity at the lid margin and reducing epithelial turnover contributing to gland obstruction.15

DEVICE FEATURES: WHAT TO LOOK FOR

Not all IPL platforms are equivalent, and understanding the technical variables that differentiate devices is essential before incorporating one into clinical practice.

Wavelength and Spectral Range

Ophthalmic IPL systems typically emit a broad, polychromatic spectrum spanning roughly the visible to near-infrared range (commonly cited as approximately 500–1,200 nm), chosen because this range is well absorbed by the key skin chromophores relevant to treatment – melanin and haemoglobin – while allowing filtration to protect deeper or unintended structures.15 Devices purpose-built for periocular use, such as TearStim, as opposed to adapted dermatological platforms, are typically restricted to a narrower band (for example, from around 580 nm) specifically to reduce the proportion of shorter, potentially more hazardous wavelengths reaching the eye.

Pulse Structure and Duration

Rather than a single continuous burst, most modern ophthalmic devices deliver a ‘flash’ composed of multiple sub-pulses, sequenced and separated by brief pauses that allow the epidermis to cool between pulses while permitting deeper cumulative heating of the target structure. Total flash duration is commonly in the order of a few hundred milliseconds, built from several shorter subpulses of varying wavelength and depth of penetration.15 This ‘regulated’ or homogenised pulse-train design is one of the features distinguishing purpose-built ophthalmic platforms, including TearStim, from earlier-generation dermatological IPL devices adapted for periocular use. IRPL delivers

250 M/s per single flash of stimulation, compared with the regular 10–20 M/s of other IPL technologies.

The number and placement of flashes delivered per eye per session is, itself, a variable worth understanding. The randomised comparison of four- versus fiveflash protocols described above found that the additional pulse, positioned temporally adjacent to the lateral canthus, produced earlier and more consistently sustained clinical improvement, suggesting that pulse placement – not just wavelength and fluence – may materially affect outcome.19

Energy Density (Fluence)

Treatment intensity is expressed in joules per square centimetre (J/cm²) and must be individualised according to Fitzpatrick skin type, since darker skin contains more melanin and will absorb proportionally more energy at a given fluence, increasing the risk of epidermal injury or pigmentary change. Published protocols typically range from around 9–13 J/cm² across Fitzpatrick types I–V, with type VI generally considered unsuitable for treatment with these devices due to excessive melanin absorption.16

Filtration and Safety Cut-Offs

Cut-off filters are used to exclude the shortest wavelengths capable of reaching intraocular structures, and eye protection – typically opaque goggles or corneal shields – together with a light-blocking mechanism for sham or non-treated sides in research settings, are standard practice.16

Treatment Protocol

Most published and manufacturer protocols use a course of four sessions spaced roughly two to four weeks apart, often at days 1, 15, 45, and 75.15,29 Benefit has been repeatedly described as cumulative, meaning outcomes assessed after only one session are likely to understate the treatment’s full effect.19

TEARSTIM: INTEGRATING DIAGNOSTICS AND TREATMENT

TearStim is a current-generation, purpose-built ophthalmic IRPL platform that applies the regulated, homogenised pulse-train design described above. It is deployed by ESW Vision and its distribution partners alongside a companion diagnostic instrument, Tearcheck, as part of an integrated dry eye workflow.29,30 Because TearStim is built on the same underlying E>Eye/IRPL technology validated across the randomised trials and cohort studies discussed above,16,19,21-28 the broader clinical evidence for periocular IRPL applies directly to it. Manufacturer and practice-level data add further TearStim-specific detail on real-world workflow and outcomes.

Diagnostic Workflow

The Tearcheck instrument is used to establish a pre-treatment baseline across a battery of objective, non-invasive measures – including non-invasive tear break-up time, tear film surface evaluation, lower lid meibography (gland loss expressed as a percentage), abortive blink rate, blink rate, eye redness, and an ocular surface inflammation evaluation. Tearcheck generates a colour-coded grading report that classifies findings from normal through to severe.30 Practice-level reporting describes this as a genuinely useful clinical and educational tool: because findings are presented visually, patients can see their own imaging and scores. Practices report that this improves patient engagement, buy-in for the recommended treatment course, and compliance with adjunctive home care.30

Treatment Delivery

TearStim sessions are typically delivered in a short course of three to four treatments, each taking only a few minutes, with the periorbital skin protected by opaque goggles and a conducting gel applied before a series of flashes delivered around the lower lid and temporal zone of each eye.15 Fluence is set according to Fitzpatrick skin type, generally in the region of 9–13 J/cm².

Post-Treatment Review

Because periocular IRPL is understood to work at least partly through improved meibum expressibility, TearStim treatment is commonly paired with manual meibomian gland expression immediately following each session, on the basis that softened meibum is more readily expressed while warm.13 Re-assessment, with the same Tearcheck battery of tests used at baseline, allows the practitioner to demonstrate change quantitatively and adjust the treatment plan if a mixed-mechanism picture – for example, persistent aqueous-deficient signs despite resolution of the evaporative component – becomes apparent.

Real-World Outcomes and Workflow Integration

Reported real-world outcomes with TearStim are encouraging. Practice-level data from an

Australian multi-site optometry group found that patients previously requiring monthly inclinic gland expression and thermal therapy could, following a completed TearStim course, be safely reviewed at intervals of eight to 10 months – a substantial reduction in chair time and ongoing burden of care for both patient and practice.30 The same report describes TearStim-based dry eye services expanding practice reach considerably, with patients travelling up to 1.5 hours to access treatment, and generating meaningful cross-referral from ophthalmologists, general practitioners, and pharmacies once a formal dry eye pathway was established.30 In the specific case of TearStim, manufacturer-collated data have reported that benefit from a completed three-to-four session course is durable, persisting for approximately six months to three years, with around 60% of treated patients reportedly maintaining benefit beyond three years.29 As with any manufacturer-sourced figure, this longevity claim should be weighed as supportive rather than independently definitive evidence pending further independent, long-term follow-up data. Nonetheless, it is broadly consistent with the cumulative, sustained treatment-effect profile demonstrated independently in the randomised trial literature above.19

THE EVIDENCE BASE

Several strands of evidence, of differing design and rigour, inform current confidence in periocular IPL for MGD-related dry eye, and are worth distinguishing clearly for CPD purposes.

Randomised Controlled Evidence

At least four randomised, placebo- or sham-controlled, double-masked trials, conducted by independent research groups across three countries, now support the efficacy of periocular IPL for MGD.16-19 This is a notably strong and consistent evidence base for a physical, device-based dry eye therapy. Most non-pharmacological dry eye interventions have been evaluated only in open-label or retrospective designs. The principal methodological strength across these trials is their paired-eye or parallel-group, sham-controlled structure, which controls for many confounders inherent to open-label case series. Limitations acknowledged by the various authors include relatively short follow-up windows in some studies, the difficulty of achieving a truly inert sham given possible light leakage around blocking filters or handpieces, and, in the original 2015 trial, that symptom scores at the final visit reflected only two of the three treatments received.16

Prospective and Retrospective Cohort Studies

Beyond the randomised trials, a substantial and geographically diverse cohort of literature – spanning Australia, Italy, Turkey, France, China, Korea, and Japan – has reported consistent improvement in objective tear film metrics, meibomian gland expressibility, and, in some cases, objective optical quality, generally without serious adverse events.21-28 These studies, being largely non-randomised or device-comparison designs, carry a higher risk of bias individually than the controlled trials, but the consistency of effect direction across different populations, devices, countries, and clinical settings meaningfully strengthens the overall weight of evidence.

Large-Scale Post-Market Surveillance

This positive picture is reinforced by real-world results reported at scale. A seven-centre, multi-country, post-market follow-up study of IRPL-treated dry eye/MGD patients (n=1,706 assessed, 818 completing the full treatment course) found the large majority of objective and subjective measures improved from baseline. Ninety-six per cent of patients said they would recommend the treatment, 80% confirmed a subjective improvement in symptoms, and 55% were able to discontinue regular eye drop use following treatment, with zero adverse events reported across more than 2,500 recorded treatment sessions.31 As a manufacturer-sponsored, non-randomised, non-placebo-controlled dataset, this study should be interpreted as supportive of real-world safety and utilisation data rather than definitive efficacy evidence, but its scale, multinational design, and consistency with the independently conducted randomised trials lend it considerable practical value.

Case-Level Clinical Reasoning

A recently published case report describes staged IPL-based management of post-blepharoplasty dry eye, in which four sessions with concurrent gland expression were associated with tear break-up time improving from 2.4 to 7.1 seconds, alongside resolution of visible inflammation; the case further illustrates that IPL predominantly addresses the evaporative component of a mixed-mechanism presentation, with a subsequently identified aqueous-deficient element requiring separate, targeted pharmacological escalation.13 While this is a single case rather than generalisable evidence, it usefully demonstrates the staged, reassess-and-adapt clinical reasoning that TFOS DEWS III advocates,12 and is directly transferable to diabetic patients, in whom evaporative and aqueous-deficient (and neurogenic) components are similarly likely to coexist.

Diabetes-Specific Evidence

It should be noted candidly that, at the time of writing, there is not yet a large, diabetes-specific randomised trial of periocular IPL. The rationale for its use in this cohort is therefore currently extrapolated from:

• The robust, multi-trial MGD-related evidence base described above,

• The well-established pathophysiological overlap between diabetic dry eye mechanisms (particularly the evaporative, gland-obstructive and autonomic-neurogenic components) and the mechanisms IPL is understood to target, and

• Real-world post-market data drawn from mixed dry eye populations that would be expected to include a proportion of diabetic patients, though this is not separately reported.31

This represents a clear and worthwhile direction for future prospective, diabetes-specific research, and practitioners should communicate this evidence gap transparently as part of informed consent when recommending IPL to diabetic patients.

SAFETY CONSIDERATIONS AND PATIENT ASSESSMENT

Before recommending IPL to any patient, and with particular care in a diabetic cohort where skin healing and microvascular status may already be compromised, a structured safety assessment should include:

• Fitzpatrick skin typing, to determine appropriate fluence and confirm suitability (type VI generally excluded from most protocols),

• Photosensitivity history, including any known allergic reaction to sunlight and current use of photosensitising medications,

• Skin integrity at the treatment site, excluding active infection, recent sunburn, tattoos, semi-permanent makeup or pigmented lesions in the treatment zone,

• Recent UV or self-tanning exposure, which is generally an exclusion criterion for a defined period prior to treatment,

• Cardiac devices, with pacemakers and implantable defibrillators generally treated as a relative contraindication,

• Ocular surgical and medical history, including recent intraocular surgery, pregnancy or breastfeeding status, and systemic comorbidities such as poorly controlled diabetes or collagen-vascular disease, which have been used as exclusion criteria in published protocols and should prompt individualised risk-benefit discussion,31

• Baseline objective ocular surface assessment, to confirm an evaporative, MGD-related component is genuinely present and to provide a quantifiable baseline against which to judge treatment response, and

• Realistic goal-setting and informed consent, particularly regarding the cumulative nature of benefit across a treatment course, the current evidence gaps specific to diabetic populations, and the likelihood that mixed-mechanism disease may require adjunctive therapy beyond IPL alone.

CONCLUSION

Dry eye disease in diabetic patients is common, frequently under-symptomatic relative to its true severity, and driven by an interlocking combination of microvascular, neurogenic, cellular, and inflammatory mechanisms centred substantially on the meibomian gland. This combination provides a strong rationale for proactive, screening-led management of the diabetic ocular surface rather than adopting a wait-and-treat approach.

Diabetic review visits already occurring for retinopathy screening represent a practical opportunity to incorporate this assessment. Periocular IPL, and specifically the TearStim IRPL platform, offers a mechanistically well-matched, non-pharmaceutical option for the evaporative, gland-obstructive component of diabetic dry eye, with an evidence base – anchored by at least four independent randomised controlled trials and reinforced by a wide, multinational cohort literature and large-scale post-market data – supporting meaningful improvement in objective tear film parameters and patient-reported symptoms.

The proposed neurostimulatory mechanism, while still requiring further dedicated validation, is conceptually well suited to a population whose dry eye is substantially driven by autonomic dysfunction. As with any mixed-mechanism presentation, staged reassessment remains essential: IPL should be understood as one component, targeting the evaporative and neurogenic contributors, within a broader, individualised management plan that may also need to address aqueous-deficient and inflammatory elements as they are identified.

This article is sponsored by Eyetek, distributor of TearStim IRPL and the Tearcheck diagnostic device.

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