Association between Dry Eye Parameters Depends on Tear Components

Contact lens fitting and changes in the tear film dynamics: mathematical and computational models review

PURPOSE

This review explores mathematical models, blinking characterization, and non-invasive techniques to enhance understanding and refine clinical interventions for ocular conditions, particularly for contact lens wear.

METHODS

The review evaluates mathematical models in tear film dynamics and their limitations, discusses contact lens wear models, and highlights computational mechanical models. It also explores computational techniques, customization of models based on individual blinking dynamics, and non-invasive diagnostic tools like high-speed cameras and advanced imaging technologies.

RESULTS

Mathematical models provide insights into tear film dynamics but face challenges due to simplifications. Contact lens wear models reveal complex ocular physiology and design aspects, aiding in lens development. Computational mechanical models explore eye biomechanics, often integrating tear film dynamics into a Multiphysics framework. While different computational techniques have their advantages and disadvantages, non-invasive tools like OCT and thermal imaging play a crucial role in customizing these Multiphysics models, particularly for contact lens wearers.

CONCLUSION

Recent advancements in mathematical modeling and non-invasive tools have revolutionized ocular health research, enabling personalized approaches. The review underscores the importance of interdisciplinary exploration in the Multiphysics approach involving tear film dynamics and biomechanics for contact lens wearers, promoting advancements in eye care and broader ocular health research.

Characteristics of the Ocular Surface in Myopic Child Candidates of Orthokeratology Lens Wear

INTRODUCTION

The purpose of this study was to investigate the characteristics of objective ocular surface parameters using non-invasive objective instruments in children with myopia who are candidates for orthokeratology lens wear.

METHODS

Children with myopia who are candidates for orthokeratology lens wear were retrospectively investigated. The subjects were divided into three age groups. The Keratograph 5M and LipiView interferometry were used to assess non-invasive tear meniscus height (TMH), non-invasive tear film break-up time (NIBUT), conjunctival hyperemia redness score (RS), meibomian gland loss (MGL) score, lipid layer thickness (LLT), and blink pattern analysis, including the number of partial blinks (PB) and total blinks (TB), as well as the partial blink rate (PBR).

RESULTS

A total of 1119 children with myopia (2070 eyes) aged 7-18 years were selected. The mean TMH, NIBUT, and LLT of the subjects was 0.21 mm, 12.45 s, and 65.28 nm, respectively. The mean RS and upper and lower MGL scores were 0.64, 1.00, and 1.06, respectively. The mean PB, TB, and PBR was 5.13, 6.46, and 0.81, respectively. Age was significantly correlated to all ocular surface parameters (p = 0.00), except for PB. NIBUT and LLT did not differ between male participants and female participants (all p > 0.05). TMH, RS, and upper and lower MGL were significantly higher in male participants than in female participants (all p < 0.01). In addition, NIBUT was positively associated with TMH (r = 0.13, p = 0.00) and LLT (r = 0.28, p = 0.00). Both upper and lower MGL were positively correlated with TMH, PB, and TB (all p = 0.00), whereas upper MGL was negatively correlated with NIBUT and LLT (all p < 0.05). TB was negatively correlated with NIBUT and LLT (all p = 0.00). PB had no relation with TMH, NIBUT, and LLT (all p > 0.05). In addition, PBR was positively correlated with NIBUT and LLT (all p = 0.00) but not with TMH, RS, or MGL (all p > 0.05). Overall, 57.00% had a TMH ≤ 0.2 mm, 43.20% had a NIBUT ≤ 10 s, 48.10% had an LLT ≤ 60 nm, and 88.10% had a PBR > 0.4.

CONCLUSIONS

Child orthokeratology candidates have enhanced tear secretion and increased meibomian gland deficiency with aging. In addition, the adult dry eye diagnostic criteria may apply to orthokeratology candidates aged 12-18 years but should be lower for younger candidates. Given the proportion of abnormal risk, it is necessary to assess tear film status and blink pattern by reliable and feasible objective examination before fitting orthokeratology.

Effects of cyclosporine on steroid-refractory dry eyes

PURPOSE

The purpose is to compare the effects of cyclosporine (CsA) on the steroid-refractory mixed-type dry eye (MTDE) and aqueous deficient dry eye (ADDE).

MATERIALS AND METHODS

We retrospectively enrolled 71 patients with levels 3 and 4 dry eye that were refractory to artificial tears and topical steroids. The effects were analyzed using the ocular surface disease index (OSDI) and standard patient evaluation of eye dryness (SPEED) questionnaires, Schirmer test II, blink patterns, lipid layer thickness (LLT), meibomian gland expressibility (MGE) and extent of meibomian gland (MG) dropout (meiboscale).

RESULTS

MTDE patients (LLT ≤60 nm, n = 38) were younger than those in ADDE (LLT >60 nm, n = 33). Before CsA treatment, they had higher Schirmer scores, less MGE, and a thinner LLT. There was no statistically significant difference in OSDI/SPEED scores between groups. CsA improved the OSDI in the ADDE group but not in the MTDE group. CsA treatment decreased the severity of superficial punctate keratitis (SPK) in both groups, but it significantly decreased partial blinks, total blinks, and partial blink rates in the ADDE group only. CsA did not increase the Schirmer score, LLT, MGE, or meiboscale grade in both groups. CsA could significantly improve subjective symptoms, SPK, and blink patterns in dry eyes refractory to topical steroids, which were more pronounced in ADDE than in MTDE.

CONCLUSION

In MTDE cases, concurrent MG treatment modalities, such as intense pulse light and/or thermal pulsation, could be considered to maximize the effects of CsA treatment.

Association between dry eye disease and depression: An umbrella review

Purpose

This umbrella review aimed to summarize the available evidence on the association between dry eye disease and depression.

Methods

We searched the Pubmed, Embase, and Cochrane databases using the search string "(Dry eye syndrome OR Keratoconjunctivitis sicca OR KCS OR Aqueous tear deficiency OR Sjogren syndrome) AND (depression OR depressive symptoms) AND (meta-analysis OR systematic review)" from inception to 20 July 2022. We considered all meta-analyses investigating the association between dry eye disease and depression.

Results

After summarizing the included meta-analyses, it was concluded that dry eye disease is associated with depression. The symptoms of dry eye disease affect the daily lives of patients, thus affecting their mood. However, further evidence is required to confirm this association.

Conclusion

This finding highlights the importance of psychological support for patients with dry eye disease. Future clinical studies should investigate the mechanism underlying the association between dry eye disease and depression.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022320619.