Contact lenses and ocular dysbiosis, from the transitory to the pathological.

Normal ocular microbiota is composed of different Gram-negative and positive bacterial communities that act as commensals on the ocular surface. An imbalance in the homeostasis of the native species or dysbiosis triggers functional alterations that can eventually lead to ocular conditions, indicating the use of contact lenses as the most relevant predisposing factor. Through a bibliographic review that added scientific articles published between 2018 and 2022, the relationship between healthy ocular microbiota and dysbiosis associated with the use of contact lenses that trigger ocular conditions was analyzed. The ocular microbiota in healthy individuals is mainly composed of bacteria from the phyla: Proteobacteria, Actinobacteria and Firmicutes. These bacterial communities associated with the use of contact lenses develop dysbiosis, observing an increase in certain genera such as Staphylococcus spp. and Pseudomonas spp., which under normal conditions are commensals of the ocular surface, but as their abundance is increased, they condition the appearance of various ocular conditions such as corneal infiltrative events, bacterial keratitis and corneal ulcer. These pathologies tend to evolve rapidly, which, added to late detection and treatment, can lead to a poor visual prognosis. It is suggested that professionals in the ophthalmology area learn about the composition of the communities of microorganisms that make up this ocular microbiota, in order to correctly distinguish and identify the causative agent, thereby providing a adequate and effective treatment to the user.

Bacterial eye infections associated with sexual transmission infections: A review.

The objective of this work was to collect updated information on Treponema pallidum, Chlamydia trachomatis and Neisseria gonorrhoeae, causing sexually transmitted infections (STIs) and etiological agents of eye infections, to provide relevant information on this public health problem. For this, a bibliographic review was carried out using different electronic databases such as: PubMed central, google academic, Lilacs, Scopus, Science Direct and Scielo, between March 2009 and August 2019. According to the WHO, more than a million people a day contract a sexually transmitted infection. For T. pallidum, a global prevalence of 0.5% is estimated for both men and women. It is a causative agent of syphilis and ocular syphilis, which manifests as uveitis. Overall, a prevalence of 2.8% in men and 3.8% in women for C. trachomatis is estimated. It is associated with oculo-genital disease, which includes STIs, inclusion conjunctivitis in adults and neonatal ophthalmia. Among its complications is trachoma, which is the leading cause of infectious blindness worldwide. Regarding N. gonorrhoeae, it has a global selection of 0.9% and 0.7% in women and men, respectively. It manifests with gonococcal conjunctivitis and neonatal ophthalmia. We can conclude that the information that relates T. pallidum, C. trachomatis and N. gonorrhoeae with their ocular compromise problems is insufficient, and even more so if we seek to find them related to each other, which makes it difficult to access data of clinical utility for visual health.

Ocular demodicosis: A review. / Demodicosis ocular: una revisión.

Demodex folliculorum and Demodex brevis are ectoparasites that inhabit the skin of humans. They have been related to alterations in the ocular surface, such as, dysfunction of Meibomian glands, blepharitis, chalazion, etc. Ocular demodicosis is characterised by the pathognomonic presence of cylindrical dandruff at the base of the eyelashes, and various symptoms including, among others, itching, lacrimation, and hyperaemia. A bibliographic review was carried out on the role of Demodex spp. in ocular disease, including publications made by the scientific society between 2005 and 2018. A significant relationship was found between prevalence and incidence of Demodex spp. in eye diseases. D. folliculorum is usually found more frequently than D. brevis in ocular infestation, with the prevalence or incidence of infestation by both species increasing with the age of the patient. In patients with blepharitis or other infectious diseases of the ocular surface, unresolved with antibacterial treatment, the search for Demodex spp. should be considered.