Corneal confocal microscopy and dry eye findings in contact lens discomfort patients

Ocular thermography and clinical measurements in symptomatic and asymptomatic soft contact lens wearers

SIGNIFICANCE

Symptoms of dryness and discomfort are the main reasons for contact lens dropout. Clinical tests for this purpose are invasive or subjective. Ocular thermography may help to assess the ocular discomfort and dryness in noninvasive and objective manner.

PURPOSE

This study aimed to investigate the relationship of ocular thermography with clinical measurements in habitual symptomatic and asymptomatic soft contact lens wearers.

METHODS

Forty habitual contact lens wearers were evaluated in two age- and gender-matched asymptomatic and symptomatic groups (Contact Lens Discomfort Questionnaire scores ≤8 and ≥14, respectively). Clinical measurements took place during visit 1 (with contact lens in situ and after contact lens removal) and at baseline after a 2-week washout period (visit 2). The Ocular Surface Disease Index (OSDI) questionnaire, noninvasive tear breakup time, bulbar conjunctival hyperemia, and corneal staining were assessed. Thermal cooling rate was computed in the central and lower cornea during natural blinking (30 s) and sustained eye opening (10 s).

RESULTS

Dry eye symptoms (OSDI score) were significantly higher in the symptomatic group during contact lens wear (p<0.001) and at baseline (p = 0.001). Thermal cooling rate was significantly higher in the symptomatic group in the lower cornea (10 s, p=0.013) with the contact lens in situ and in the central cornea (30 s, p=0.045) after contact lens removal. At baseline, dry eye symptoms (OSDI score) significantly correlated with cooling rate in the central cornea region for the symptomatic group (30 s: r = -0.5, p=0.03; 10 s: r = -0.63, p=0.005). Noninvasive tear breakup time correlated with cooling rate in the central cornea region at baseline in the symptomatic group (30 s, r = 0.6, p=0.005; 10 s, r = 0.55, p=0.018). Cooling rate in the central cornea region (10-s duration, p<0.0001) and noninvasive tear breakup time (p<0.0001) were identified as significant predictor variables for dry eye symptoms at baseline.

CONCLUSIONS

Noninvasive tear breakup time and thermal cooling rate were identified as significant predictor variables for contact lens-induced dry eye. These findings may suggest the potential for the additional application of ocular thermography in the evaluation of contact lens discomfort.

The clinical impact of contact lens wear on neural structure and function of the cornea

Contact lens (CL) use is growing rapidly, with a current estimate of over 100 million wearers worldwide. Vast improvements in materials and designs have occurred over the past decades with advancements in the understanding of ocular surface health with CL wear. However, the potential impact of CL on neural structures and function of the ocular surface, particularly in relation to the richly innervated cornea, remain poorly understood. Problems with sensation such as CL discomfort and conditions that may be associated with lens wear including dry eye disease also remain pervasive. This narrative review discusses the findings from studies involving soft or rigid CL wearers, assessed with c linical techniques designed for examining the neural integrity of the cornea, namely in vivo confocal microscopy and esthesiometry. While the collective findings remain equivocal in terms of the changes in corneal nerve morphology and function with conventional CL wear, more specialised CLs, namely orthokeratology lenses, which mechanically manipulates the structure of the cornea seem to produce more prominent changes in nerve distribution and sensitivity reduction. Given the intricate relationship between neural and immune mechanisms in maintaining balanced ocular surface health, the potential links between these structural and functional findings with parainflammation and neuroinflammation, as well as clinical issues including CL discomfort and dry eye disease, are also explored.

In vivo confocal microscopy findings of cornea and tongue mucosa in patients with Sjögren's syndrome

INTRODUCTION AND OBJECTIVES

We aimed to investigate whether Sjögren's syndrome (SS) had distinctive findings in tongue confocal microscopy in a non-invasive manner.

MATERIALS AND METHODS

This retrospective case-control study evaluated corneal and tongue confocal microscopy findings of the right eyes of 25 patients with aqueous deficient dry eye and 12 healthy volunteers without dry eye findings. There were a total of 14 patients diagnosed with SS-associated dry eye (SSDE), while 11 cases were evaluated as non-Sjögren dry eye (NSDE).

RESULTS

A significant difference was observed in the dendritic cell count at the corneal subbasal nerve level between the SSDE and NSDE groups (P=.018). In SSDE group, the confocal microscopy images of dendritiform hyperreflective inflammatory cells in the tongue mucosa were in favor of inflammation. However, these findings were not found in patients with NSDE or in controls.

CONCLUSIONS

This study showed that confocal microscopy provided a non-invasive evaluation of the inflammatory cells in the tongue of SS patients.

Functional Changes of the Ocular Surface Sensory Nerves Due to Contact Lens Use in Young Symptomatic and Asymptomatic Users

Purpose

The purpose of this study was to analyze the differences in corneal sensory nerve functionality in young asymptomatic (CL-A) and symptomatic (CL-S) contact lens (CL) users.

Methods

CL wearers (23.8 ± 1.0 years, n = 31) were classified as CL-S with an Ocular Surface Disease Index (OSDI) ≥ 13 (n = 14) or CL-A. Users of eye glasses (EG; 24.5 ± 0.8 years, n = 29) with OSDI < 13 participated as controls. The sensations evoked by mechanical, chemical (gas esthesiometer), and cold (4°C saline drops) stimuli were measured using the Visual Analogue Scales (VASs). Moreover, tear volume, tear break up time (TBUT), blinking frequency (BF), and ocular surface temperature (OST; IR thermography) were also measured.

Results

Mechanical and chemical stimuli produced similar scores in the CL-A and EG participants, although the CL-A subjects referred to stronger irritation (p < 0.05). Likewise, the VAS intensity in response to cold stimuli did not differ between CL-A and EG subjects, while the ability to detect cold was significantly worse in CL-S users (p < 0.05). CL-A users had a similar tear volume, a higher BF (p < 0.01) and shorter TBUT (p < 0.001) to EG wearers, and blinking and TBUT were also altered significantly in CL-S users (p < 0.01). Interestingly, the OST was significantly lower in CL-A users (p < 0.05) than in EG wearers, but not in CL-S users.

Conclusions

Using CLs modifies corneal sensitivity, blinking and tearing in young volunteers. Even if they have yet to develop clinical signs of inflammation, they display changes in corneal sensitivity consistent with the sensitization of corneal nociceptors and the inhibition cold thermoreceptors, phenomena that occur under inflammatory conditions. The differences in corneal sensitivity and OST between CL-A and CL-S users could reflect the extent of nerve damage and inflammation at the ocular surface.

Comparison Between Optimal Pulsed Technology and Meibomian Gland Massage Treatment for Contact Lens-Related Meibomian Gland Dysfunction

Objective: The purpose of this study was to compare the effectiveness of optimal pulsed technology (OPT) and meibomian gland massage (MGM) in alleviating the signs and symptoms of contact lens-related meibomian gland dysfunction (CL-MGD). Methods: This prospective, randomized, controlled study included 90 patients (180 eyes) diagnosed with CL-MGD and were assigned to the OPT group (n = 60 eyes), MGM group (n = 60 eyes), and control group (n = 60 eyes). All participants were examined at baseline (D0), day 21 (D21), and day 42 (D42) for the ocular surface disease index (OSDI), noninvasive tear break-up time (NITBUT), noninvasive tear meniscus height (NITMH), meibomian gland score (MGS), meibomian gland score (MGYSS), best-corrected visual acuity, and intraocular pressure. Results: The OSDI scores and NITBUT improved after treatment in all the three groups. The OSDI scores in OPT and MGM groups were significantly lower compared with that in the control group at D21 and further decreased at D42. The NITBUT in OPT and MGM groups increased compared with the control group at D21 and further increased at D42, and the NITBUT in OPT group increased compared with the MGM group at D21 and D42. The MGYSS both improved after treatment in the OPT and MGM groups, The MGYSS in OPT and MGM groups decreased compared with the control group at D21 and further decreased at D42, and the MGYSS in the OPT group decreased compared with the MGM group at D21 and D42. The NITMH and MGS had no differences after treatment. Conclusions: Results imply that OPT or MGM treatment can be safely used to relieve symptoms of CL-MGD. In addition, OPT treatment was found to be more effective in improving the general stability of the tear-film in CL-MGD.

Impact of Dry Eye Disease on the Uncorrected Distance Visual Acuity after Small Incision Lenticule Extraction

The aim of this study was to explore the impact of dry eye disease (DED) on the uncorrected distance visual acuity (UDVA) and refractive status after small incision lenticule extraction (SMILE). This prospective cohort study enrolled 29 patients (DED group, 11 eyes; non-DED group, 18 eyes) who underwent SMILE in our center from July to September 2022. The examinations on DED, refractive status and UDVA were performed before surgery, and on day 7 and 20 after surgery. The results showed that on day 20 after SMILE, subjects in the non-DED group reported greater changes of ocular surface disease index value increase and tear-film breakup time reduction compared to baseline than those in the DED group (p < 0.001 and p = 0.048, respectively). Compared to preoperative status, DED patients had greater improvements of UDVA and better optometric outcomes on day 20 after surgery than non-DED subjects (p = 0.008 and 0.026, respectively). Multiple linear regression analysis showed age, contact lens daily wearing time, and tear meniscus height before surgery were of the highest value to predict UDVA on day 20 after SMILE in contact lens wearers (p = 0.006, 0.010 and 0.043, respectively). In conclusion, preoperative tear function could affect UDVA after SMILE. The impact of DED on UDVA and refraction should be taken into consideration before surgery.

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.

Evaluation of corneal dendritic cell density and subbasal nerve density in contact lens wearers using IVCM: A systematic review and meta-analysis

Purpose

To evaluate the subclinical changes in corneal dendritic cell density (CDCD) and corneal subbasal nerve density (CSND) in asymptomatic contact lens (CL) wearers.

Methods

Databases including PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched for trials and studies reporting the changes of corneal CDCD and CSND in contact lens wearers published until 25 June 2022. PRISMA guidelines as well as recommended meta-analysis practices were followed. Meta-analysis was conducted using RevMan V.5.3 software.

Results

After the screening, 10 studies with 587 eyes of 459 participants were included. Seven studies reported the data of CDCD. Compared with the control group, CDCD in the CL wearers was higher (18.19, 95% CI 18.8–27.57, p = 0.0001). Type of in vivo confocal microscopy (IVCM), wear duration, and frequency of lens change were sources of heterogeneity. The difference in CSND between CL wearers and the control group was insignificant, and subgroup analysis did not reveal a source of heterogeneity.

Conclusion

Overall, CDCD increased in CL wears, while CSND did not show significant differences. IVCM is a feasible tool to assess subclinical changes in CL wearers.

Bacteria and Dry Eye: A Narrative Review

(1) Background: Dry eye is a multifactorial disease of the ocular surface, the incidence of which has been increasing sharply. The pathogenesis of dry eye, especially in terms of the bacterial flora, has drawn great attention. Additionally, the potential treatment methods need to be explored. (2) Methods: We reviewed more than 100 studies and summarized them briefly in a review. (3) Results: We summarized the bacterial communities found on the ocular surface in the general population and patients with dry eye and found a relationship between dry eye and antibiotic therapy. We identified the possible mechanisms of bacteria in the development of dry eye by discussing factors such as the destruction of the antibacterial barrier, infectious diseases, microbiome homeostasis, inflammatory factors on the ocular surface and vitamin deficiency. (4) Conclusion: We systematically reviewed the recent studies to summarize the bacterial differences between patients with dry eye and the general population and brought up several possible mechanisms and possible treatment targets.

Comparison Between Heated Eye Mask and Intense Pulsed Light Treatment for Contact Lens-Related Dry Eye

Background: Contact lens-related dry eye (CLDE) is common in contact lens (CL) wearers and can lead to ocular pain, decreased visual quality, and reduced quality of life. Objective: The purpose of this prospective, randomized, examiner masked study was to compare the effectiveness of intense pulsed light (IPL) and heated eye mask (HEM) for relieving CLDE. Methods: The final analysis included 60 patients (30 in the IPL group and 30 in the HEM group) who were using CL and had been suffering contact lens discomfort for more than a year. The IPL treatment group had two IPL treatments spaced 3 weeks apart, whereas the HEM group received HEM daily for 6 weeks (42 days). Non-invasive tear break-up time (NITBUT), tear-film lipid layer (TFLL), conjunctival fluorescein staining, meibum gland quality and expression, conjunctival redness score, ocular surface disease index (OSDI), best-corrected visual acuity, endothelial cell count, and intraocular pressure were assessed at baseline: first visit (V1), second visit (V2), and third visit (V3). Results: The mean age of the IPL group was 28.6 ± 4.3 years (16 females, 53%) and that of the HEM group was 28.6 ± 4.2 years (16 females, 53%). Mean NITBUT for the IPL group at V2 was 5.53 ± 0.77 sec (p < 0.001) and at V3 was 7.72 ± 0.88 sec (p < 0.001); the IPL group demonstrated a clinically and statistically significant improvement in mean NITBUT. In addition, the HEM group showed a clinically and statistically significant improvement in mean NITBUT at V3 (5.86 ± 0.76 sec, p < 0.001). At V3, the C-OSDI, TFLL score, and meibum gland quality and expressibility all increased considerably (p < 0.05) in both groups. Conclusions: Our results imply that IPL or HEM treatment of CLDE can be safely used to relieve symptoms of CLDE. In addition, IPL treatment is more effective in improving the general stability of the tear-film and decreasing the need for artificial tears in CLDE.

Factors influencing the 8-item contact lens dry eye questionnaire score and comparison of translations in Japanese soft contact lens wearers

PURPOSE

To determine (1) the factors associated with a high degree of self-reported symptoms with Japanese translations of the 8-Item Contact Lens Dry Eye Questionnaire (J-CLDEQ-8) in a cross-section of soft contact lens (SCL) wearers in Japan and (2) whether the difference in translation of the CLDEQ-8 affects the scores between validated and non-validated versions of the Japanese translation.

METHODS

Habitual SCL wearers completed the validated J-CLDEQ-8 and a previous non-validated version. Demographics and SCL history questions were queried when they presented for routine eye care in nine geographically distinct clinics across Japan. The following risk factors for high J-CLDEQ-8 scores (≥11) were tested: sex, age, SCL replacement (daily disposable vs. bi-weekly and monthly reusable), years of SCL wear, and self-reported use of rewetting drops. The scores of the validated and non-validated questionnaires were compared.

RESULTS

Significant patient-related risk factors for high J-CLDEQ-8 scores were female sex, use of reusable SCLs, longer years of SCL wear, and use of rewetting drops. Scores for six out of eight questions in the validated J-CLDEQ-8 were significantly higher than those of the non-validated version, resulting in a significant difference in the average total score between the two questionnaires (validated J-CLDEQ-8: 10.5 ± 5.9 vs non-validated J-CLDEQ-8: 9.5 ± 5.8, P < 0.001).

CONCLUSIONS

Female sex, use of reusable SCLs, longer years of SCL wear, and use of rewetting drops were significant risk factors for high J-CLDEQ-8 scores in a cross-sectional clinical population of Japanese SCL wearers. Symptoms with SCL are not predicted by age and must therefore be queried at follow-up visits for all SCL wearers. Differences in the two translations affected the ability of the questionnaire to identify individuals with high symptoms associated with SCL wear.

Associations between Binocular Vision Disorders and Contact Lens Dissatisfaction

SIGNIFICANCE

These data demonstrate that binocular vision disorders (BVDs) contribute to contact lens (CL) dissatisfaction independently of CL discomfort (CLD) in myopic, pre-presbyopic, adult, single-vision CL wearers.

PURPOSE

This study aimed to determine whether BVDs contribute to CL dissatisfaction and whether this contribution is independent of CLD.

METHODS

Participants attended one clinical visit while wearing their habitual CLs. Symptoms from CLD and BVDs were measured with the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and Convergence Insufficiency Syndrome Survey (CISS), respectively. A comprehensive binocular vision (BV) assessment was performed. The Ocular Surface Disease Index (OSDI) was used to measure CL dissatisfaction from CLD and BVDs based on reported correlations between the CLDEQ-8 and the CISS with the OSDI. Participants were categorized according to their CL comfort status (CLD [≥12 on CLDEQ-8] or non-CLD [<12 on CLDEQ-8]) and BV status (BVD or non-BVD).

RESULTS

Seventy-six participants completed the trial, and 19 (25%) were diagnosed with BVD. Those diagnosed with BVD scored higher than did those diagnosed with non-BVD for the OSDI (25.1 ± 12.7 vs. 10.7 ± 7.3, P < .001) and CISS (18.7 ± 7.7 vs. 11.9 ± 5.9, P = .001), but not the CLDEQ-8 (P = .25). Those categorized as having CLD scored higher than did those categorized as having non-CLD for the OSDI (19.0 ± 12.3 vs. 9.3 ± 5.9, P = .003) and CISS (16.1 ± 6.8 vs. 11.0 ± 6.2, P = .001). There were no significant interactions between BV status and CL comfort status for any questionnaire (P > .08).

CONCLUSIONS

Higher scores for OSDI in those with CLD or BVD indicate that both conditions contribute to CL dissatisfaction. Higher scores for the CISS in those with CLD suggest a degree of overlap for some BVD symptoms. Nonsignificant differences between BVD and non-BVD for the CLDEQ-8 suggest that BVDs contribute to CL dissatisfaction independently of CLD.

Determining the information needs of contact lens wearers for better education and more support: a qualitative study

BACKGROUND

Designing educational interventions tailored to the needs of Contact Lens Wearers (CLWs) are important and necessary. The present study aimed to determine the information needs of CLWs to educate and provide information to them to increase their knowledge and reduce complications and non-compliance behaviors.

METHODS

A qualitative approach was applied and semi-structured interviews were conducted in three contact lenses (CL) clinics in Iran among all their practitioners and 24 purposively selected patients. Data were analyzed using the Lundman and Graneheim conventional content analysis.

RESULTS

The qualitative analysis revealed knowledge and skill themes as two main categories. The knowledge category includes five subcategories of basic information for the CLWs, acquaintance with the CL, caring for CL, hygiene and vigilance of CL, and challenges of using CL. The skill category consists of two subcategories, including handling/insertion and removal of the CL, and stabilization of learned information. Moreover, 36 sub-subcategories emerged from these seven subcategories that reflected the information needs of CLWs.

CONCLUSIONS

A clear understanding of CLWs' information needs can help to design and develop appropriate educational approaches to overcome training barriers such as physicians' time constraints and high workload. Moreover, it can help deal with CLWs' insufficient knowledge and provide the required information simply and practically with the possibility of enough repetition.

Evaluation of preoperative dry eye in people undergoing corneal refractive surgery to correct myopia

AIM

To investigate the incidence of preoperative dry eye and related factors in patients undergoing corneal refractive surgery to correct myopia.

METHODS

A total of 141 patients with myopia who underwent corneal refractive surgery were surveyed by questionnaires, tear film break-up time (BUT) test, Schimer I test (SIt), corneal fluorescein staining (FL) test and diagnosed according to the currently recognized domestic diagnostic criteria for dry eye. Correlation analysis of factors such as age, gender, regular wearing of contact lens (CL), diopter (spherical equivalent), corneal thickness, and corneal curvature that may affect the onset of dry eye was carried out to clarify the main influencing factors.

RESULTS

There were 64 patients (45.39%) diagnosed with dry eye. The male patients (20.31%) was significantly less than that of non-dry eye subjects (41.56%; χ ²=7.260, P=0.007); the proportion of patients with dry eye wearing CL (81.25%) was significantly higher than that of non-dry eye subjects (51.95%; χ ²=13.234, P<0.001); the median diopter level of dry eye patients was -6.59 (IQR: -8.87, -4.58) D, and the median diopter level of non-dry eye subjects was -5.69 (IQR: -7.15, -4.03) D. The diopter level of dry eye patients was significantly higher (Z=-2.086, P=0.019). However, the age, best corrected visual acuity, and intraocular pressure of dry eye patients were not statistically different from those of non-dry eye subjects (t=-0.257, -0.383 and 0.778, P=0.798, 0.702, and 0.438); the corneal thickness and corneal curvature (K1 and K2) were also not statistically different either (Z=-1.487, -1.036 and -1.707, P=0.137, 0.300, and 0.088). The research further analyzes the three significant factors in the single factor analysis (gender, CL wear, and diopter) in a multi-factor way: CL wear and diopter were the influencing factors of dry eye disease. Among them, CL wear increased the risk of dry eye by 2.934 times compared with no CL wear; for every 1 D increase in diopter, the risk of dry eye increased by 0.761 times.

CONCLUSION

Preoperative dry eye is relatively common in patients who undergo corneal refractive surgery to correct myopia, especially in patients who have a history of CL wear and a high diopter level before surgery. Therefore, it is necessary to carry out preoperative screening and timely treatment of dry eye to obtain the best treatment outcome and postoperative satisfaction.

Effect of material and care system combination on subclinical inflammation of the ocular surface in soft contact lens wear

PURPOSE

To investigate the ocular subclinical inflammatory response in two soft contact lens materials when used in combination with two different care systems ('solutions').

METHODS

Fifteen established soft contact lens wearers wore each of two lenses: Acuvue® 2 (CH) and Acuvue® Oasys® (SiH) or no lenses in random sequence for one week. Two care systems were used: a peroxide system: Oxysept 1 Step® (P) for the right lens and Opti-Free® Replenish® (MPS) for the left lens. After one week of lens/no lens wear, in vivo confocal microscopy (IVCM) of corneal and conjunctival regions was carried out. Density of presumed dendritic cells (DC) and 'white spots' (WS) were quantified. Impression cytology of the bulbar and upper eyelid margin conjunctivae was carried out and samples were analysed for CD45+, CD3+ and CD11c+ cells.

RESULTS

The SiH + MPS combination showed a greater inflammatory response compared to SiH + P in seven out of 12 parameters investigated (p < 0.05). The remaining five were not statistically different between the two solutions. The converse was found for the CH lens, with four of the 12 parameters showing a greater response with the P solution compared to the MPS (p < 0.05).

CONCLUSION

This study suggests that the SiH lens investigated demonstrated an upregulated response when used with a MPS compared to a P solution whereas the converse is true for the CH lens which showed a reduced response when used with a MPS compared to a P solution. This finding aids in the understanding of the biological underpinnings of manifest corneal inflammatory events during contact lens wear.

Quantification of Increased Corneal Subbasal Nerve Tortuosity in Dry Eye Disease and Its Correlation With Clinical Parameters

Purpose

This study quantified corneal subbasal nerve tortuosity in dry eye disease (DED) and investigated its correlation with clinical parameters by proposing an aggregated measure of tortuosity (Tagg).

Methods

The sample consisted of 26 eyes of patients with DED and 23 eyes of healthy volunteers, which represented separately the dry eye group and the control group. Clinical evaluation of DED and in vivo confocal microscopy analysis of the central cornea were performed. Tagg incorporated six metrics of tortuosity. Corneal subbasal nerve images of subjects and a validation data set were analyzed using Tagg. Spearman's rank correlation was performed on Tagg and clinical parameters.

Results

Tagg was validated using 1501 corneal nerve images. Tagg was higher in patients with DED than in healthy volunteers (P < 0.001). Tagg was positively correlated with the ocular surface disease index (r = 0.418, P = 0.003) and negatively correlated with tear breakup time (r = -0.398, P = 0.007). There was no correlation between Tagg and visual analog scale scores, corneal fluorescein staining scores, or the Schirmer I test.

Conclusions

Tagg was validated for quantification of corneal subbasal nerve tortuosity and was higher in patients with DED than in healthy volunteers. A higher Tagg may be linked to ocular discomfort, visual function disturbance, and tear film instability.

Translational Relevance

Corneal subbasal nerve tortuosity is a potential biomarker for corneal neurobiology in DED.

Treatment of contact lens related dry eye with intense pulsed light

AIM

The prevalence of contact lens related dry eye (CLDE) is high and can lead to ocular discomfort, reduced quality of vision and life. The aim of this study was to assess the efficacy of intense pulsed light (IPL) treatment in alleviating signs and symptoms of CLDE.

DESIGN

Prospective, randomised, examiner masked study.

METHODS

This prospective study was conducted on 152 eyes of 76 patients (IPL group, n = 76 eyes; control group, n = 76 eyes) wearing contact lens (CL) and experiencing CLDE for more than 1 year. The IPL treatment group underwent two IPL treatment sessions at 3-week intervals while the control group received sham IPL treatment. Best-corrected visual acuity (BCVA), ocular surface disease index (OSDI), non-invasive breakup time (NITBUT), tear film lipid layer (TFLL) quality, fluorescein staining (FS), meibum gland (MG) quality and expression, endothelial cell count (ECC) and intraocular pressure (IOP) were assessed at baseline (D-0), day-21 (D-21) and day-42 (D-42) after IPL treatment.

RESULTS

The mean age of treatment group and control group was 28.47 ± 5.16 years (21 females, 28 %) and 28.58 ± 4.33 years (23 females, 30 %) respectively. IPL treatment group had clinically and statistically significant improvement in mean NITBUT was observed at D14 (5.24 s, P<0.001) and D28 (6.08 s, P<0.001). OSDI, TFLL score and MG quality and expressibility all improved significantly (P<0.001) at D-42, whereas BCVA, ECC and IOP showed no significant changes at D-21 and D-42 in IPL treatment group. The control group showed no significant improvement in all parameters at D-21 and D-42.

CONCLUSION

Our findings suggest that CL related DE can be safely alleviated with IPL treatment as it reduced the severity of symptoms, improved the overall tear film stability and reduced artificial tear use in participants with CLDE.

Evaluation of tear film and the morphological changes of meibomian glands in young Asian soft contact lens wearers and non-wearers

Background

The aim of this study was to explore the differences in terms of tear film and meibomian glands (MGs) between young Asian soft contact lens (CL) wearers and non-wearers.

Methods

A prospective, cross-sectional observational study was conducted using 148 subjects (63 non-wearers, and 85 soft CL wearers who had been wearing CLs for more than 1 year) recruited from a clinic in Tianjin, China. All subjects first responded to an Ocular Surface Disease Index (OSDI) questionnaire and then underwent a standardized dry eye examination, which included measuring tear meniscus height (TMH), non-invasive tear breakup time (NIBUT), and corneal fluorescein staining (CFS). The MGs were evaluated via ImageJ, distorted MG count and the MG dropout were recorded.

Results

Compared to the control group (non-wearers), the CL group recorded higher OSDI and CFS scores, lower TMH and NITBUT values, a larger distorted MG count, and larger MG dropout (all P < 0.05). Pearson correlation analysis found a correlation between MG dropout and the duration of CL use (r = 0.440, P < 0.001), OSDI (r = 0.298, P = 0.006), and CFS scores (r = 0.442, P < 0.001).

Conclusion

CL wearers showed higher MG dropout and reduced TMH and NITBUT, which likely contributes to severe CL-related dry eye symptoms. CL use may lead to a higher MG dropout rate, and the extent of the MG dropout presumably influences the tear film status in CL wearers.

Presbyopia and the aging eye: Existing refractive approaches and their potential impact on dry eye signs and symptoms

Every part of the human body is subject to aging, including the eye. An increased prevalence of dry eye disease with age is widely acknowledged. Aging threatens ocular surface homeostasis, altering the normal functioning of the lacrimal functional unit and potentially leading to signs and symptoms of dry eye. Additional age-related processes take place within the crystalline lens, leading to presbyopia and cataractogenesis. Correction strategies for presbyopia and cataracts may directly or indirectly challenge the ocular surface. Contact lenses disturb the normal structure of the tear film and can interact negatively with the ocular surface, further deteriorating an already unbalanced tear film in presbyopes, however, newer contact lens designs can overcome some of these issues. Moreover, cataract and corneal refractive surgeries sever corneal nerves and disrupt the corneal epithelium and ocular surface, which can influence surgical outcomes and aggravate dryness symptoms in older age groups. This review summarises the current understanding of how the invasive nature of contact lens wear and cataract and refractive surgery influence signs and symptoms of ocular dryness in an aging population.

Corneal epithelial dendritic cell density in the healthy human cornea: A meta-analysis of in-vivo confocal microscopy data

PURPOSE

Numerous studies have reported a wide range of corneal epithelial dendritic cells (CEDC) density using in-vivo confocal microscopy in healthy participants. It is necessary to establish normal CEDC values for healthy corneas to enable differentiation from pathological corneas. This meta-analysis aimed to establish CEDC density and distribution and examine their relationship with age and sex.

METHODS

A systematic review of the literature of studies using the Heidelberg Retinal Tomograph with Rostock Corneal Module and reporting CEDC density in healthy subjects up to December 2018 was conducted via Medline, Google Scholar, Scopus, PubMed, Embase and Cochrane library. A random effect modeling approach was used to obtain the results of meta-analysis and meta-regression was conducted to estimate the effect of age and sex.

RESULTS

38 studies reported central and 9 reported peripheral inferior CEDC density of 1203 participants (mean age 46.0 ± 12.2, range 18-81 years). CEDC density in the central and peripheral inferior cornea was 26.4 ± 13.6 cells/mm² (95% CI:22.5-26.8) and 74.9 ± 22.7 cells/mm² (95%CI:59.8-90.0), respectively. No effect of age was found on central CEDC density (p = 0.63); whereas peripheral CEDC density decreased with increasing age (p = 0.02). CEDC density was not influenced by sex at either location (p > 0.48).

CONCLUSION

This study established that the density at the peripheral inferior cornea is three-fold higher than at the central cornea. Peripheral but not central CEDC density decreased with increasing age. There are limited studies in youth (<18 years), precluding a more detailed analysis. Sex does not appear to be a significant factor in CEDC density.

An Amplifying Cascade of Contact Lens-Related End-of-Day Hyperaemia and Dryness Symptoms

End-of-day (EOD) symptoms of dryness are too often the cause of poor soft contact lens (SCL) tolerance and abandonment of wear. This review examines an amplifying cascade model for these symptoms, which involve thin tear layers on contact lens (CL) front surfaces being susceptible to evaporation-related short tear breakup (TBU) times. Susceptibility to faster tear loss by evaporation may be exacerbated by other forms of tear instability, such as lipid and mucin deficiencies as well as lens surface soiling. Bulbar and palpebral conjunctival hyperaemia and associated faster evaporation of warmer pre-conjunctival tears could also contribute to evaporative dry eye EOD symptoms. In CL wearers, a cascade of increasing hyperaemia toward the end of day, associated increasing tear temperature and evaporative loss, shortened TBU times (TBUTs) and increased osmolarity, all elevate the risk of higher symptom levels according to progressive amplification of this cascade. Chronic wound healing responses to SCL wear, perhaps related to limbal conjunctival trauma, stem cell deficiency and persistent epitheliopathy, as well as one or more immune responses, may contribute directly or indirectly to inflammation and the amplifying evaporative dryness cascade. A diurnal cycle that culminates in EOD symptoms appears to involve a process of recovery from causal mechanisms after lens removal, which allows lenses to be worn comfortably, at least initially the next day. Possible recovery processes are discussed in this review as are procedures that may help de-amplify an inflammatory, evaporative dryness cascade and alleviate EOD symptoms. Evidence of an accrual of adverse responses over long periods of more or less successful lens wear indicate an incremental failure to recover from EOD hyperaemia. Such incremental failure could help explain how SCL wear too often needs to be abandoned after many years of comfortable wear.