During seasonal influenza, mortality is concentrated in the very young and the elderly, whereas during flu pandemics, young adults are often affected at a high rate. In temperate regions, the number of influenza cases varies from season to season. Lower vitamin D levels, presumably due to less sunlight, lower humidity, lower temperature, and minor changes in virus proteins caused by antigenic drift contribute to annual epidemics that peak during the winter season. In the northern hemisphere, this is from October to May (more narrowly December to April), and in the southern hemisphere, this is from May to October (more narrowly June to September). There are therefore two distinct influenza seasons every year in temperate regions, one in the northern hemisphere and one in the southern hemisphere. In tropical and subtropical regions, seasonality is more complex and appears to be affected by various climatic factors such as minimum temperature, hours of sunshine, maximum rainfall, and high humidity. Influenza may therefore occur year-round in these regions. Influenza epidemics in modern times have the tendency to start in the eastern or southern hemisphere, with Asia being a key reservoir of influenza viruses.IAV and IBV co-circulate, so the two have the same patterns of transmission. The seasonality of ICV, however, is poorly understood. ICV infection is most common in children under the age of 2, and by adulthood most people have been exposed to it.
The UKGTS trial found that latanoprost treatment results in more than halved risk of sight loss.Meta-analysis suggests that latanoprost is more effective than timolol in lowering intraocular pressure (IOP). However, it often causes iris pigmentation. While current evidence suggests that this pigmentation is benign, careful lifetime evaluation of patients is still justified. Closed-angle glaucoma
Patients who had elevated IOP despite iridotomy and/or iridectomy (including patients of Asian descent), latanoprost was significantly more effective than timolol in two double-blind, monotherapy trials (8.2 and 8.8 mm Hg vs 5.2 and 5.7 mm Hg for latanoprost vs timolol at 12 and 2 weeks, respectively). Adverse effects
Listed from most to least common:
> 5–15%: blurred vision, burning and stinging, conjunctival hyperemia, foreign body sensation, itching, increased (brown) pigmentation of the iris (causing heterochromia), punctate epithelial keratopathy
4%: cold or upper respiratory tract infections, flu-like syndrome
1–4%: dry eyes, excessive tearing, eye pain, lid crusting, lid edema, lid erythema (hyperemia), lid pain, photophobia
1–2%: chest pain, allergic skin reactions, arthralgia, back pain, myalgia
< 1 % (only severe or life-threatening effects): asthma, herpes keratitis, iritis, keratitis, retinal artery embolus, retinal detachment, toxic epidermal necrolysis, uveitis, vitreous hemorrhage from diabetic retinopathy
A single case report links latanoprost use to the progression of keratoconus.Research suggests that wiping the eye with an absorbent pad after the administration of eye drops can result in shorter eyelashes and a lesser chance of hyperpigmentation in the eyelid, compared to not wiping off excess fluid. Pregnancy
Use in pregnant women is limited due to high incidence of abortion shown in animal experiments.