Ekspresija i prognostička vrijednost imunohistokemijskih biljega matičnih stanica raka u bolesnika s melanomom srednje očne ovojnice [Expression and prognostic value of cancer stem cell markers in patients with uveal melanoma]

Uveal melanoma is a rare ocular malignancy with intrinsic resistance to conventional systemic chemoterapy. This study investigated paraffin embedded samples of 31 patient with primary choroidal and ciliary body melanoma in order to determine the presence of tumor cells that express putative cancer stem cell markers CD133, CD117 (c-kit), CD34, CD20 and CD15 and their possible impact on survival. Immunohistochemical expression of CD133 was observed in 16 of 22 samples with AEC chromogen. CD117 expression was observed in 12 of the 31 samples when AEC chromogen was used and in 14 of 26 samples when DAB was used. CD15 positivity was seen in 3 out of 30 samples with AEC and in 6 out of 26 samples with DAB. CD20 and CD34 exhibited no positivity in the tested samples. During the average follow-up time of 8.7 years, more than half of the patients died due to metastatic disease. The Kaplan-Meier plots showed a significantly shorter overall and disease-free survival in CD117-positive patients when AEC chromogen was used. CD133 and CD15 expression had no impact on patients’ survival. In multivariate analysis, patients expressing CD117 AEC had 4 times higher risk of lethal outcome in comparison with CD117 AEC negative patients

Eye and Pregnancy

Hormonal, metabolic, hemodynamic, vascular and immunological changes that occur during pregnancy can affect the function of the eye. These changes are commonly transient, but in some cases they may be permanent and have consequences even after childbirth. The ocular effects of pregnancy may be physiological or pathological and can be associated with the development of new ocular pathology or may be modifications of pre-existing conditions. The most common physiological changes are alterations of corneal sensitivity and thickness, decreased tolerance to contact lenses, decreased intraocular pressure, hemeralopia and refractive errors. Possible posterior segment changes include worsening of diabetic retinopathy, central serous chorioretinopathy, increased risk of peripheral vitreochorioretinal dystrophies and retinal detachment. Thus, it should be kept in mind that the presence of any ocular symptoms in a pregnant woman requires ophthalmologic examination and further management

Corneal collagen crosslinking: from basic research to clinical application

Corneal collagen crosslinking is a promising new treatment of progressive corneal ectasia. Its clinical use has been rapidly increasing since it was originally introduced in 1997 as the first treatment that can improve biomechanical stability of theweakened cornea. The method is based on the combined action of photosensitizer riboflavin (vitamin B2) and ultraviolet A light, which induce the formation of new covalent bonds between the collagen fibers. Our systematic search of literature in English has yielded only eight prospective trials with the efficiency and safety data published to date. However, all of the published studies reveal a halt in the progression or a slight improvement of corneal ectasia with the low complication and failure rates after the treatment. In this review we are highlighting the method’s history, scientific basis and its current clinical application in order to provide clinicians with the recent data on its benefits and potential risks

Dry Eye Symptoms and Signs in Long-Term Contact Lens Wearers

The aim of this study is to analyze the relationship between the self-reported symptoms and objective signs of dry eye disease in long-term rigid gas-permeable (RGP) or soft contact lens (SCL) wearers. The study included 32 eyes of Caucasian RGP and SCL wearers between the age of 21 and 42 who wore contact lenses continuously on a daily basis for more than 2 years. Symptoms were assessed according to the Ocular Surface Disease Index (OSDI). Clinical assessments included corneal fluorescein staining according to the National Eye Institute (NEI) staining grid, tear film break-up time (TBUT) and Schirmer II test. There were more male (62.5%) than female (37.5%) patients with a higher proportion of RGP wearers among males (40% vs. 17%) in the study. The mean duration of daily lens wear was 10.6 ± 5.37 hours, with a significantly higher proportion of patients who wore their lenses for prolonged hours in the soft contact lens group (p<0.05). There was a trend towards a higher proportion of self reported mild and moderate dry eye in females and soft contact lens wearers. No RGP wearer in this study had a NEI corneal staining grid score higher than 2. A moderate negative correlation was found between daily lens wear duration and TBUT (Pearson’s coefficient, r=–0.47) as well as Schirmer II values and higher OSDI score, i.e. mild and moderate dry eye categories (r=–0.50). A strong positive correlation was found between and TBUT and Schirmer II values (r=0.74). The results of the study emphasize the importance of early and accurate diagnosis of dry eye disease for successful long term RGP and SCL contact lens wear which will hopefully motivate future larger scale investigations on dry eye related problems in contact lens wearers

Expression and prognostic value of putative cancer stem cell markers CD117 and CD15 in choroidal and ciliary body melanoma

AIMS: The aim of the present study was to immunohistochemically investigate the expression and prognostic significance of putative cancer stem cell markers CD117 (c-kit), CD34, CD20 and CD15 in a cohort of patients with primary choroidal and ciliary body melanoma. ----- METHODS: The immunohistochemical expression of these markers was evaluated using 3,3'-diaminobenzidine tetrahydrochloride (DAB) and 3-amino-9-ethylcarbazole (AEC) chromogens on paraffin-embedded tissue samples from 40 patients who underwent enucleation in the period from 1985 through 2000. Thirty-one patients had adequate tissue specimens for the analysis. ----- RESULTS: CD117 overexpression was observed in 12 of the 31 samples (39%) when AEC chromogen was used and in 14 of 26 (54%) samples when DAB was used. CD15 positivity was seen in three out of 30 (10%) samples with AEC and in six out of 26 (23%) samples with DAB. CD20 and CD34 exhibited no positivity in the tested samples. During the average follow-up time of 8.7 years (range 0.5-22 years), 17 patients (55%) died due to metastatic disease. The Kaplan-Meier plots showed a significantly shorter overall and disease-free survival in CD117-positive patients when the AEC chromogen was used. CD15 expression was not associated with patients' survival. In multivariate analysis, patients expressing the CD117 AEC had 4.13 times higher risk of lethal outcome in comparison with CD117 AEC negative patients. ----- CONCLUSIONS: Our retrospective cohort study has for the first time demonstrated a small proportion of CD15-positive uveal melanomas. CD117 AEC overexpression was associated with a worse outcome in patients with choroidal and ciliary body melanoma. Further studies should confirm the validity of these observations and their potential for targeted treatment modalities

Ispravljanje hiperopije, hiperopičnog i miješanog astigmatizma excimer laserom: jučer, danas i sutra

The broad acceptance of “spot scanning” or „flying spot“ excimer lasers in the last decade has enabled the domination of corneal ablative laser surgery over other refractive surgical procedures for the correction of hyperopia, hyperopic and mixed astigmatism. This review outlines the most important reasons why the ablative laser correction of hyperopia, hyperopic and mixed astigmatism for many years lagged behind that of myopia. Most of today‘s scanning laser systems, used in the LASI K and PRK procedures, can safely and effectively perform low, moderate and high hyperopic and hyperopic astigmatic corrections. The introduction of these laser platforms has also significantly improved the long term refractive stability of hyperopic treatments. In the future, further improvements in femtosecond and nanosecond technology, eye-tracker systems, and the development of new customized algorithms, such as the ray-tracing method, could additionally increase the upper limit for the safe and predictable corneal ablative laser correction of hyperopia, hyperopic and mixed astigmatism.Široka rasprostranjenost nove generacije „spot scanning“ excimer lasera, odnosno lasera s pomičnom točkastom zrakom, omogućila je u posljednjih deset godina dominaciju laserske ablacijske kirurgije rožnice u korekciji dalekovidnosti, dalekovidnog i miješanog astigmatizma nad drugim refrakcijskim kirurškim postupcima. U članku su navedeni najvažniji razlozi zbog kojih je laserska kirurgija rožnice u ispravljanju dalekovidnosti, dalekovidnog i miješanog astigmatizma niz godina zaostajala za laserskim ispravljanjem kratkovidnosti. Većina današnjih lasera temeljenih na navedenoj tehnologiji omogućuje sigurno i učinkovito ispravljanje niskih, srednjih i visokih dalekovidnosti i astigmatizama uz pomoć postupaka LASI K i PRK. Uvođenje ovih laserskih sustava također je unaprijedilo i dugoročnu stabilnost rezultata nakon tretmana. Može se očekivati da će daljnji napredak u femtosekundnoj i nanosekundnoj tehnologiji, sustavima za praćenje pokreta oka, te razvoj novih individualiziranih algoritama poput metode “ray-tracing” u budućnosti pomaknuti današnje granice sigurne i predvidljive ablacijske laserske korekcije dalekovidnosti, kao i dalekovidnog i miješanog astigmatizma

Refraction Errors and Their Treatment in Adolescence

U posljednjim desetljećima primjetan je značajan porast refrakcijskih grešaka u dječjoj i adolescentskoj dobi. To se posebno odnosi na kratkovidnost koja je u svim razvijenim zemljama u porastu, dok je u nekim zemljama poprimila epidemijske razmjere. Iako su do danas provedena brojna istraživanja, načini sprečavanja nastanka i napredovanja rasta refrakcijskih grešaka i dalje su uglavnom nepoznati. Do potpunijih saznanja adolescentima s refrakcijskim greškama treba nastaviti ispravno propisivati tradicionalna pomagala poput naočala i kontaktnih leća. U ovom članku iznijet ćemo pregled trenutačnih saznanja o mehanizmima nastanka refrakcijskih grešaka, najčešćim simptomima te danas dostupnim načinima njihova ispravljanja i liječenja.The incidence of refraction errors in children and adolescents has significantly increased over the last decades. This particularly refers to myopia, whose incidence has increased in all developed countries and even become epidemic in some of them. Despite a number of studies, the methods for their prevention and the prevention of their increased incidence remain mainly unknown. Until we have a more thorough knowledge of refraction errors, the adolescents with refraction errors should be prescribed traditional aids such as glasses and contact lenses. This article provides a review of the current knowledge about the mechanisms of their development, the most common symptoms, and the available methods for their correction and treatment

Retinal nerve fibre layer thickness in conditions of severe ischemia in patients without glaucoma

Introduction: Ischemia, most often caused by carotid disease, contributes to or causes a numerous ocular changes including optic nerve and ganglion cell damage, glaucoma, anterior and posterior segment changes. The perimetric changes in ischemia partially overlap with those caused by glaucoma. New diagnostic tools such as scanning laser polarimetry can detect retinal nerve fiber layer loss in glaucoma up to 6 years earlier than the first perimetric changes. Still, it is not yet clear if and up to what level laser polarimetry can show changes in RNFL caused by ischemia only, and whether these changes differ from the pure glaucomatous ones. In our pilot study we tried to investigate influence of significant carotid stenosis on retinal nerve fiber layer. Materials and Methods: Eight consecutive patients with carotid stenosis of more than 70% and no other eye disease influencing optic nerve. Results: RNFL loss can be found in the most of analyzed patients. The level of the RNFL impairment is not equal in the both eyes of patients having a different degree of stenosis on two sides probably due to the factors such as microvascular status. Conclusion: RNFL suffers changes in carotid stenosis. The results demand further investigation because the possibility of the precise estimation of ischemical damage to the RNFL can be of crucial importance in diagnosing and treatment of patients having glaucoma and ocular ischemia at the same time

Dry Eye Symptoms and Signs in Long-Term Contact Lens Wearers

The aim of this study is to analyze the relationship between the self-reported symptoms and objective signs of dry eye disease in long-term rigid gas-permeable (RGP) or soft contact lens (SCL) wearers. The study included 32 eyes of Caucasian RGP and SCL wearers between the age of 21 and 42 who wore contact lenses continuously on a daily basis for more than 2 years. Symptoms were assessed according to the Ocular Surface Disease Index (OSDI). Clinical assessments included corneal fluorescein staining according to the National Eye Institute (NEI) staining grid, tear film break-up time (TBUT) and Schirmer II test. There were more male (62.5%) than female (37.5%) patients with a higher proportion of RGP wearers among males (40% vs. 17%) in the study. The mean duration of daily lens wear was 10.6 ± 5.37 hours, with a significantly higher proportion of patients who wore their lenses for prolonged hours in the soft contact lens group (p<0.05). There was a trend towards a higher proportion of self reported mild and moderate dry eye in females and soft contact lens wearers. No RGP wearer in this study had a NEI corneal staining grid score higher than 2. A moderate negative correlation was found between daily lens wear duration and TBUT (Pearson’s coefficient, r=–0.47) as well as Schirmer II values and higher OSDI score, i.e. mild and moderate dry eye categories (r=–0.50). A strong positive correlation was found between and TBUT and Schirmer II values (r=0.74). The results of the study emphasize the importance of early and accurate diagnosis of dry eye disease for successful long term RGP and SCL contact lens wear which will hopefully motivate future larger scale investigations on dry eye related problems in contact lens wearers

Effects of Alpha-MSH on Corneal Epithelial Lesions in Rats

We investigated the influence of alpha-melanocyte stimulating hormone (a-MSH) on the healing of corneal epithelial lesions in male Wistar rats. The lesions were induced by abrading corneal epithelium with a surgical lancet under a biomicroscope. Before the abrasion corneal epithelium was softened with 40% ethanol. a-MSH drops in a concentration of 1×10–4 mg/mL significantly promoted epithelial healing, when compared to the control group treated with 0.9% NaCl. Significant reduction of ocular irritation was also observed. Topical a-MSH medication could promote the healing of corneal wounds and reduce local inflammatory response without the major side effects of the corticosteroid therapy