Different conjunctival adaptive response in patients with aqueous-deficient and with mucous-deficient dry eyes

Treatment of Dry Eye Disease (DED) in Asia: Strategies for Short Tear Film Breakup Time-Type DED

Dry eye disease (DED) is a multifactorial disorder in which tear fluid homeostasis is lost, resulting in increased tear film osmolarity and ocular surface irritation. In Asia, the short tear film breakup time-type DED, which has become a global problem in recent years, is common. While the mainstay of DED treatment in the West is the suppression of inflammation, the first goal of treatment is the stabilization of the tear film in Asia. To date, artificial tears and steroid eye drops have been the main treatment for DED. However, artificial tears require frequent administration of eye drops and thus pose adherence problems, while steroids have problems with side-effects (cataracts, increased intraocular pressure). This review evaluates the new generation therapies in Asia based on what is known about them and demonstrates that they are more effective for DED than traditional therapies such as artificial tears and steroids. Based on considerations, it is proposed that the optimal treatment for the short tear film breakup time-type DED is the initial application of mucin-secretion-enhancing eye drops (long-acting diquafosol) and oral supplements; and if additional treatment is needed, cyclosporine eye drops and the adjunctive therapies presented in this review are added.

Ocular surface changes in recurrent pterygium cases post-operatively treated with 5-fluorouracil subconjunctival injections

INTRODUCTION:

To investigate the ocular surface changes occurring in eyes with recurrent pterygium post-operatively treated with 5-fluorouracil intralesional injections.

METHODS:

Retrospective observational study of recurrent pterygium cases treated with weekly intralesional injections of 0.1 mL (5 mg) of 5-fluorouracil (10 injections). Impression cytology samples taken from the lesion, the healthy conjunctivae (inferior, superior, and contralateral to injury), and the cornea before and after treatment were analyzed. Clinical ocular characteristics (including Schirmer's test and break-up time) were evaluated during treatment.

RESULTS:

A total of 15 eyes were treated, with the mean follow-up of 27 ± 8.7 months (mean ± standard deviation). Prior to treatment initiation, the ocular surface citology over the pterygium was found to be abnormal. No epithelial cells (27%) and a lower goblet cell density (73%) compared to the healthy conjunctivae (p < 0.01) were found. Squamous metaplasia was observed to some degree in the cornea (100%), pterygium (81%) and healthy conjunctivae (73%). Following treatment, pterygium composition had changed: epithelial cell number (100%) and goblet cell density (47%) had increased (p < 0.05). Goblet cell density was also increased in healthy conjunctivae (67%; p < 0.05). The degree of squamous metaplasia decreased in the cornea (67%), pterygium (45%), and healthy conjunctivae (60%; p < 0.05). No adverse effects were reported, recurrence progression was arrested, and conjunctival redness and dry-eye severity level were decreased in all cases (p < 0.01).

DISCUSSION:

The cytology of ocular surface in recurrent pterygium is abnormal. After weekly intralesional 5-fluorouracil injections, it tends to normalize. The 5-fluorouracil compound is a safe and effective treatment to prevent pterygium recurrence.

The use of conjunctival ultraviolet autofluorescence (CUVAF) as a biomarker of time spent outdoors

PURPOSE

Conjunctival ultraviolet autofluorescence (CUVAF) has been used in previous Southern Hemisphere myopia research as a marker for time spent outdoors. The validity of CUVAF as an indicator of time spent outdoors is yet to be explored in the Northern Hemisphere. It is unclear if CUVAF represents damage attributed to UV exposure or dry eye. This cross-sectional study investigated the association between CUVAF measures, self-reported time spent outdoors and measures of dry eye.

METHODS

Participants were recruited from University staff and students (n = 50, 19-64 years; mean 41). None were using topical ocular medications (with the exception of dry eye treatments). Sun exposure and dry eye questionnaires (Ocular Surface Disease Index and McMonnies) were completed by the participant. Dryness was also assessed using slit lamp biomicroscopy and invasive tear break up time. Images of the temporal and nasal conjunctiva from the right and left eye were captured using a bespoke photography system. The total CUVAF area, average CUVAF pixel intensity per mm(2) and total CUVAF pixel intensity were analysed using MATLAB R2013a (The MathWorks Inc).

RESULTS

Of the 50 participants, 42% were classified as having dry eye. Self-reported sunglasses use was negatively associated with all CUVAF measures (Kruskal Wallis total CUVAF area, p = 0.04, ptrend  = 0.03, average CUVAF pixel intensity p = 0.02, ptrend  = 0.02, total CUVAF pixel intensity: p = 0.04, ptrend  = 0.02). Time spent outdoors was positively associated with all CUVAF measures (Spearman's correlation coefficients, total CUVAF area: r = 0.37, p = 0.01, average CUVAF pixel intensity: r = 0.36, p = 0.01, total CUVAF pixel intensity: r = 0.37, p = 0.01) and remained significant when sunglasses use was controlled for (partial correlation, total CUVAF area: r = 0.32, p = 0.03, average CUVAF pixel intensity: r = 0.39, p = 0.01, total CUVAF pixel intensity: r = 0.39, p = 0.03). Neither CUVAF area nor intensity measures were associated with any dry eye measure (Ocular Surface Disease Index: all p ≥ 0.41, corneal staining: all p ≥ 0.38, McMonnies: all r ≤ 0.09 all p ≥ 0.52, slit lamp biomicroscopy: all r ≤ 0.20 all p ≥ 0.17, invasive tear break up time: all r ≤ -0.07 all p ≥ 0.31).

CONCLUSIONS

CUVAF area and intensity were not associated with clinical measures of dry eye. Greater CUVAF area and intensity were associated with wearing sunglasses less frequently and spending more time outdoors. If sunglass wear is accounted for, CUVAF may be a useful biomarker of time spent outdoors in future myopia studies.

New Perspectives on Dry Eye Definition and Diagnosis: A Consensus Report by the Asia Dry Eye Society

For the last 20 years, a great amount of evidence has accumulated through epidemiological studies that most of the dry eye disease encountered in daily life, especially in video display terminal (VDT) workers, involves short tear film breakup time (TFBUT) type dry eye, a category characterized by severe symptoms but minimal clinical signs other than short TFBUT. An unstable tear film also affects the visual function, possibly due to the increase of higher order aberrations. Based on the change in the understanding of the types, symptoms, and signs of dry eye disease, the Asia Dry Eye Society agreed to the following definition of dry eye: "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The definition stresses instability of the tear film as well as the importance of visual impairment, highlighting an essential role for TFBUT assessment. This paper discusses the concept of Tear Film Oriented Therapy (TFOT), which evolved from the definition of dry eye, emphasizing the importance of a stable tear film.

Goblet cells of the normal human bulbar conjunctiva and their assessment by impression cytology sampling

Goblet cells of the conjunctiva are the main source of mucus for the ocular surface. The objectives of this review are to consider the goblet cells as assessed by various histological, cytological and electron microscopy methods, and to assess the consistency of published reports (over more than 25 years) of goblet cell density (GCD) from impression cytology specimens from nominally healthy human subjects. Reported GCD values have been notably variable, with a range from 24 to 2226 cells/mm² for average values. Data analysis suggests that a high density of goblet cells should be expected for the healthy human conjunctiva, with a tendency toward higher values in samples taken from normally covered locations (inferior and superior bulbar conjunctiva) of the open eye (at 973 +/- 789 cells/ mm²) than in samples taken from exposed (interpalpebral) locations (at 427 +/- 376 cells/mm²). No obvious change in GCD was found with respect to age, perhaps because the variability of the data did not allow detection of any age-related decline in GCD. Analyses of published data from 33 other sources indicated a trend for GCD to be lower than normal across a spectrum of ocular surface diseases.

Conjunctival impression cytology changes induced by oral isotretinoin

PURPOSE

To evaluate the bulbar conjunctiva using impression cytology in patients submitted to oral isotretinoin treatment.

METHODS

A prospective, cohort study was carried out in a referral ophthalmology practice at the Federal University of Paraíba and in the External Eye Disease Laboratory of the Federal University of São Paulo. Twenty-eight patients with acne vulgaris were selected. Impression cytology specimens collected from the temporal bulbar conjunctiva and the superior bulbar conjunctiva of both eyes before and after 3 months of oral isotretinoin treatment were assessed. The doses of isotretinoin varied from 0.35 to 0.88 mg . kg . d.

RESULTS

The percentage of patients in whom impression cytology results were normal was significantly lower during oral isotretinoin treatment compared to the pretreatment phase, decreasing from 75% to 43% in the temporal bulbar conjunctiva and from 100% to 82% in the superior bulbar conjunctiva. In both regions, the parameters most affected were cell-to-cell contact, nucleus-to-cytoplasm ratio, and goblet cell density.

CONCLUSION

Oral isotretinoin for the treatment of acne induces alterations in the conjunctival epithelium of a significant percentage of patients treated with the drug. These alterations are seen both in the exposed conjunctiva (temporal bulbar region) and in the unexposed conjunctiva (superior bulbar region).