Tear-film-oriented diagnosis for dry eye

Effects of cataract surgery on symptoms and findings of dry eye in subjects with and without preexisting dry eye

PURPOSE

To compare dry eye symptoms and findings in post cataract surgery eyes' with and without preexisting dry eye.

STUDY DESIGN

Prospective, observational case-control study.

METHODS

Sixty-seven eyes that had undergone cataract surgery were included; 48 were classified into group D (preexisting dry eye) and 19 into group N (no preexisting dry eye). No subjects received perioperative treatment for dry eye. We evaluated between-group differences in symptom scores, corrected distance visual acuity (CDVA), tear film breakup time (BUT), tear film breakup pattern (BUP), and ocular surface fluorescein staining scores, at 1 week, 1 month, and 3 months postoperatively.

RESULTS

Symptoms were unchanged in group N, but improved in group D (P < .001) postoperatively. CDVA was improved after surgery in both groups (P < .001). BUT was shorter preoperatively in group D than in group N although this difference was absent 1 month postoperatively. Fluorescein staining scores significantly increased at 1 month postoperatively in group N (P = .01), but did not change in group D. During the perioperative period, the predominant BUP was the random break pattern in both groups (≥ 85%). From 1 week to 3 months, dimple break patterns decreased in group D (P = .007), whereas spot break patterns increased (P = .01).

CONCLUSIONS

Cataract surgery has an influence on tear film stability and the ocular surface. There was either a transient improvement or worsening of ocular surface wettability in some patients without preexisting dry eye.

The Effects of High Molecular Weight Hyaluronic Acid Eye Drop Application in Environmental Dry Eye Stress Model Mice

Hyaluronic acid (HA) ophthalmic solution is widely used in dry eye treatment worldwide. However, there are no reports comparing the dry eye treatment effects of high molecular weight HA with low molecular weight HA. Sixty eight-week-old C57BL/6 mice were assigned to the following 6 groups and exposed to environmental dry eye stress (EDES) that mimics office work environment: 1) 0.1% low molecular weight HA (LMWHA) eye drops, 2) 0.3% LMWHA eye drops, 3) 3% diquafosol sodium (DQ) eye drops, 4) 0.15% high molecular weight HA (HMWHA) eye drops, 5) no treatment with exposure to EDES (EDES+/Treatment-), and 6) no treatment without exposure to EDES (EDES-/Treatment-). After EDES, the HMWHA group had significantly longer break-up time (BUT) than the 0.1%, 0.3% LMWHA groups and the DQ group. After EDES, the HMWHA group had significantly lower lissamine green staining scores than the LMWHA and DQ groups. Subepithelial presumed dendritic cell density in the HMWHA group was significantly lower than the EDES+/Treatment- group. After EDES exposure, Conjunctival Muc5AC mRNA expression in the HMWHA group was significantly higher than the 0.1 and 0.3% LMWHA groups. Ophthalmic HMWHA solution may have a better dry eye treatment effect than LMWHA or DQ solution, owing to its anti-inflammatory effect.

Advances in the diagnosis and treatment of dry eye

The core mechanism of dry eye is the tear film instability. Tear film-oriented diagnosis (TFOD) is a concept to clarify the cause of tear film instability by tear film, and tear film-oriented treatment (TFOT) is a concept to treat dry eye disease by replacing the lacking components of the tear film layer based on the TFOD. In TFOD, the fluorescein breakup pattern of the tear film is important, and the subtype of dry eye can be judged to some extent from the breakup patterns. Current noninvasive devices related to the dynamic analysis of the tear film and visual acuity enabled the diagnosis of dry eye, subtype analysis, and the extent of severity. In Asian countries, secretagogues represent the main treatment in TFOT. Since meibomian gland dysfunction is a factor that greatly affects the tear breakup time, its treatment is also essential in the dry eye treatment strategy. A newly discovered dry eye subtype is the short breakup time-type (BUT) of dry eye. The only abnormal finding in this disease is the short BUT, suggesting a relationship with ocular neuropathic pain and eye strain. Recently, data from many studies have accumulated which show that dry eye is a life-style disease. In addition to the treatment of dry eyes, it is becoming possible to prevent the onset by intervening with the daily habits, diet, exercise and sleep, etc. It has been pointed out that oxidative stress is also involved in the pathology of dry eye, and intervention is being carried out by improving diet and taking supplements. Future research will be needed to link clinical findings to the molecular biological findings in the tear film.

Characteristics of tear abnormalities associated with benign essential blepharospasm and amelioration by means of botulinum toxin type A treatment

PURPOSE

To investigate the characteristics of tear abnormalities with benign essential blepharospasm (BEB) and the effect of botulinum toxin type A (BTX-A) treatment.

STUDY DESIGN

Prospective and clinical study.

METHODS

Forty eyes of 40 patients (12 men and 28 women, ages 63.5 ±12.9) with BEB and tear abnormalities were enrolled.

RESULTS

The average scores for subjective symptoms as evaluated by the visual analog scale (VAS) were 46.3 and Dry Eye-Related Quality-of-Life Score (DEQS) were 63.7. The fluorescein breakup time (FBUT) was 2.7 ± 1.6 sec. Among fluorescein breakup patterns (FBUPs), dimple break, with the corresponding mechanism of decreased wettability was the most frequent, observed in 29 eyes (73%). The NEI score was 0.4 ± 0.7 and the van Bijesterveld score was 0.6 ± 0.8; the Schirmer 1 test value was 13.1 ± 9.4 mm. Eighteen patients received BTX-A treatment, and significant improvement was found in severity of subjective symptoms both on VAS and DEQS as well as for FBUT. The main FBUPs changed from dimple break to random break.

CONCLUSION

Tear abnormalities seen in BEB correspond to short BUT-type dry eye (DE), subclassified into decreased wettability DE in view of FBUPs.

Contribution of Mucins towards the Physical Properties of the Tear Film: A Modern Update

Instability of the tear film (TF) protecting the ocular surface results in dry eye syndrome (DES), the most prevalent public health ophthalmic disease affecting the quality of life of 10 to 30% of the human population worldwide. Although the impact of the tear film lipid layer (TFLL) and of the aqueous tears (AT) to the TF stability is extensively studied, in contrast the contribution of the secretory mucins (SM) and of the membrane-associated mucins (MAM), i.e., one of the most abundant molecular classes in AT and in the corneal epithelium respectively, remains poorly defined. However, it is well known that in DES both types of mucins are quantitatively or qualitatively deficient. Numerous studies since the 1990s until now have proposed direct involvement of SM and MAM in the material properties (viscoelasticity, hydration, and protection of the ocular surface; synergistic cooperation with the rest of the TF layers; etc.) and stability of TF. These theories will be reviewed here in the context of the classical and modern in vitro and in vivo results that allow their reappraisal and in view of the novel mucin secretion enhancing pharmaceuticals, which have opened innovative routes for the therapy of DES.

Bromhexine elevates REP2 expression to stimulate secretion from human primary conjunctiva fornix epithelial cells

Bromhexine was reported to relieve the symptoms of Sjogren Syndrome at an early stage. However, the underlying mechanism remains unclear. Here, we administered bromhexine at low doses in human primary conjunctival fornix epithelial cells, and found it stimulated MUC5AC secretion and lipid droplet production. Expression of the metabolism-related gene CHML was also upregulated by bromhexine treatment, and REP2, the protein produced by the CHML gene, was induced. These results suggest that bromhexine is a potential candidate eye drop drug for the treatment of multiple types of dry eye disease, not only limited to the treatment of dry eyes in Sjogren Syndrome.