Dry eye is a medical problem of epidemic proportions, especially among the elderly in developed countries. The treatment of dry eye is still largely inadequate because there is no way of permanently restoring normal tear function and secretion at present. At present, virtually all therapeutic regimens include tear supplements; however, their main drawbacks are the need for frequent instillation, inadequate ocular surface protection and limited mode of action, focusing on rewetting only. A new gellable lubricant eye drop (Systane lubricant eye drops, Alcon) has been designed using the novel concept of a pH-sensitive hydroxypropyl-guar component that prevents surface desiccation, reduces friction and acts as a mucomimetic. The purpose of this review is to consider this topical therapy and its properties. Currently published data on Systane is reviewed, putting an accent on its novel multiple modality of action. By being pH sensitive, Systane adapts its viscosity to the ocular surface pH, which tends to be higher in dry eye. It becomes more viscous when the eye is drier, thus, providing better ocular surface protection. In addition, its characteristics reduce ocular surface friction, which is another factor that exacerbates dry eye symptoms. Data published so far show that it is also well tolerated by the patient, thus, significantly reducing dry eye symptoms and improving the patient's quality of life. By implementing this novel approach, Systane has contributed significantly to dry eye treatment.

Background: Dry eye disease (DED) stands out as one of the most common eye conditions encountered in clinical settings. This study aimed to determine the diagnostic ability and feasibility of post-blink blur time (PBBT) in detecting patients with DED symptoms. Methods: The study included 200 subjects, 100 with and 100 without DED symptoms defined by the Schein questionnaire, who underwent assessment of DED signs [visual acuity, PBBT, conjunctival hyperemia, lid-parallel conjunctival folds—LIPCOF, tear film break-up time—TBUT, fluorescein corneal staining, and meibum score]. Results: DED subjects had a lower PBBT than controls (p < 0.001), with subjective (6 (1–45) s vs. 8 (1–70) s) and objective (6 (2–33) s vs. 8 (2–50) s) PBBT measurements being similar between repeats. The correlations between subjective and objective PBBT measurements were significantly positive (R = 0.873, p < 0.001). Subjective PBBT was negatively related to the Schein questionnaire (R = −0.217, p = 0.002), conjunctival hyperemia (R = −0.105, p = 0.035), and corneal staining (R = −0.153, p = 0.031), while positively related to the TBUT (R = 0.382, p < 0.001) and meibum score (R = 0.106, p = 0.033). Logistic regression analysis showed DED symptoms were significantly associated with subjective PBBT (AOR 0.91, p = 0.001), TBUT (AOR 0.79, p < 0.001), meibum score (AOR 0.65, p = 0.008), LIPCOF (AOR 1.18, p = 0.002) and corneal staining (AOR 1.14, p = 0.028). Conclusions: Subjective self-reported PBBT is a reliable and non-invasive screening test for evaluating time-wise changes in visual acuity and detecting a tear film dysfunction.

Hereditary hemochromatosis (HH) is an inherited iron metabolism disorder. It is caused by an autosomal recessive disorder resulting from a C28Y8 HFE gene mutation. Mutations in the HFE gene may result in iron accumulation and oxidative stress in the retina, resulting in macular degeneration. This article describes two patients with HH who developed vision difficulties. Both patients were subjected to a retinal exam, multimodal imaging, and electrodiagnostic techniques, which revealed structural and functional degeneration of the central macula. Fundus photography, fluorescein angiography (FA), and fundus autofluorescence (FAF) revealed changes at the level of the retinal pigment epithelium (RPE) in the center of the macula, while optical coherence tomography (OCT) revealed subfoveal accumulation of hyperreflective material at and below the RPE. The multifocal electroretinogram (mfERG) confirmed a decreased cone response, whereas the full-field electroretinogram (ERG) revealed no pathological findings. In addition, patients underwent genetic testing, which ruled out the possibility of hereditary macular dystrophy. Considering macula findings and the nature of the patients' primary illness, we believe that the higher concentration and accumulation of iron and photoreceptor metabolic products have led to dysfunction in the RPE, which has led to morphological and functional changes in the macula.