Tomasz Chorągiewicz

Kynurenic acid and kynurenine aminotransferases in retinal aging and neurodegeneration

The kynurenine aminotransferases (KATs) KAT I and KAT II are pivotal to the synthesis of kynurenic acid (KYNA), the only known endogenous glutamate receptor antagonist and neuroprotectant. KAT I and II have been found in avian, rodent, and human retina. Expression of KAT I in Müller cell endfeet and KAT II in retinal ganglion cells has been documented. Developmental changes in KAT expression and KYNA concentration in the avian and rodent retina have also been found. Studies of retinal neurodegeneration have shown alterations in KYNA synthesis in the retina in response to retinal ganglion cell loss. In DBA/2J mice, a model of ocular hypertension, an age-dependent decrease of retinal KYNA and KATs was found. In the corpora amylacea in the human retina intensive KAT I and II immunoreactivity was demonstrated. In summary, these findings point to the potential involvement of KYNA in the mechanisms of retinal aging and neurodegeneration.

Drug bioavailability from topically applied ocular drops. Does drop size matter

The application of drops containing ocular medicines to the conjunctival sac is the most common method of drug delivery to the anterior segment of the eye. Although this route of application seemingly displays numerous advantages, obtaining effective drug concentration at its site of action is challenging. The bioavailability of a topically applied drug depends on various factors related to the eye, to the drug and formulation, to the drop, and to the patient. The present article discusses their relative significance. From a drop applied to an eye, at most 5% of a drug dose enters the ocular structures. Of utmost importance for effective ocular drug delivery are patient compliance and the physicochemical properties of the drug. For a given concentration of an active substance, drop size may determine drug adverse effects but does not influence its efficacy.

Współczesne możliwości leczenia cukrzycowego obrzęku plamki — wyniki własne

Liczba chorych na cukrzyce rośnie z kazdym rokiem. Duza ich cześc to osoby mlode, aktywne zawodowo. Powiklania oczne cukrzycy, w tym cukrzycowy obrzek plamki (DME), istotnie wplywają na codziennie funkcjonowanie pacjentow. Dzieki nowoczesnym lekom, laseroterapii i metodom operacyjnym mozliwe jest skuteczne leczenie powiklan ocznych cukrzycy. Jest to jednak proces zlozony, wymagający doświadczonego zespolu specjalistow umiejących odpowiednio lączyc rozne metody terapeutyczne. Celem pracy jest przedstawienie wynikow wlasnych leczenia mlodych pacjentow z DME za pomocą monoterapii anty-VEGF lub w skojarzeniu z innymi metodami terapeutycznymi.

Nasally located congenital optic disc pit with concomitant maculopathy

Optic disc pit is a congenital optic disc anomaly, which can be associated with maculopathy. The case of an unusually nasally located pit with concomitant maculopathy in a 64-year-old woman is presented.

Postoperative presbyopia correction with intraocular lenses implantation in cataract patients – current trends

The most effective and most frequently used method for presbyopia correction in cataract patients involves the implantation of presbyopic intraocular lenses. Diffractive intraocular lenses and extended depth of focus IOLs are the two main trends in presbyopia correction in cataract patients nowadays. Mariusz spyra1, ewelina Cisek2,3, agnieszka Cisek1,3, stanisław Orkisz3, Paweł Klonowski2, tomasz Chorągiewicz2, Dominika Nowakowska2, Robert Rejdak2