Sinan Tatlipinar

Polymorphisms of the DNA repair genes XPD and XRCC1 and the risk of age-related macular degeneration.

PURPOSE Oxidative stress seems to be an important factor in the development of age-related macular degeneration (AMD). The role of DNA repair mechanisms has also received attention recently in AMD pathogenesis. This case-control study was conducted to determine the frequency of polymorphisms in two DNA repair enzyme genes, xeroderma pigmentosum complementation group D (XPD), codons 312 and 751, and x-ray cross-complementing group 1 (XRCC1), codons 194 and 399, in patients with AMD and in disease-free control subjects. METHODS Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to analyze XPD Asp312Asn and Lys751Gln and XRCC1 Arg194Trp and Arg399Gln in 120 patients with AMD (65 with dry type and 55 with wet type) and in age-matched 205 disease-free control subjects. RESULTS Genotypic and allelic distributions of the polymorphisms were detected. For the XPD polymorphism, although the allele frequencies were not different between the patients and healthy control subjects, there was a significant difference between frequencies for the XPD751 Gln/Gln genotype in AMD patients (9%) and healthy control subjects (19%; P=0.02). The XPD751 Gln/Gln genotype seemed to have a protective effect against development of AMD (odds ratio, 0.41; 95% confidence interval, 0.19-0.88). Stratification by subtype of AMD revealed that the XPD751 Gln/Gln genotype was significantly lower only in the patients with dry type (P=0.02). These interactions remained nearly significant after Bonferroni correction (P<0.0125). Haplotype analysis for the two XPD polymorphisms revealed that the haplotype GC (312Asp-(751)Gln) was a protective haplotype against AMD. No statistically significant difference was found for the genotypic and allelic distributions of the polymorphisms in the XRCC1 gene between the patients and the control subjects. CONCLUSIONS Polymorphism in XPD codon 751 may be associated with the development of AMD.

Fundus autofluorescence in acute and chronic central serous chorioretinopathy

Background:  A prospective evaluation of the pattern of fundus autofluorescence in cases of acute versus chronic central serous chorioretinopathy (CSR).

Autofluorescence and OCT features of Bietti’s crystalline dystrophy

Bietti’s crystalline dystrophy (BCD) is an autosomal recessive retinal degeneration characterised by innumerable glistening intraretinal dots scattered over the fundus. This retinal degeneration was first described in three patients by Bietti in 1937 with crystalline deposits in the retina and limbal cornea.1 Progressive retinal degeneration and sclerosis of the choroidal vessels ultimately result in progressive night blindness and constriction of the visual field approximately in the third and fourth decade of life. Histopathological studies disclosed evidence of advanced panchoroidal atrophy characterised by a marked loss of the RPE and choriocapillaris and mild retinal gliosis. Focal hypertrophy, hyperplasia and intraretinal migration of RPE cells were observed.2 To the best of our knowledge, the optical coherence tomography (OCT) features of BCD have been described in a single case only.3 Herein, we report the OCT, fundus autofluorescence (FAF) and near-infrared autofluorescence (NIR AF) findings in three patients with Bietti’s crystalline retinopathy. …

Short-term effects of a single intravitreal bevacizumab injection on retinal vessel calibre

Purpose:  The aim was to investigate the short‐term effects of a single intravitreal bevacizumab injection on the retinal vessel calibre in patients with neovascular age‐related macular degeneration and in patients with diabetic macular oedema.

Subjective Visual Experience and Pain Level during Phacoemulsification and Intraocular Lens Implantation under Topical Anesthesia

Purpose: To investigate the subjective visual experiences and pain during the phacoemulsification and intraocular lens (IOL) implantation under topical anesthesia, and whether these parameters change according to the stage of phacoemulsification cataract surgery. Methods: Forty eyes of 40 patients with cataract undergoing phacoemulsification and IOL implantation under topical anesthesia were included in this study. The patients were told that they would be asked about their visual experiences and pain level, if any, during every stage of the surgery. As for degree of the pain, a 5-grade scale was used. The surgery was divided into 9 stages, i.e., clear corneal incision, continuous curvilinear capsulorhexis, side-port incisions at 3 and 9 o’clock positions, hydrodissection, nuclear rotation, phacoemulsification, bimanual irrigation and aspiration, IOL implantation, apposition of corneal incisions with stromal hydration. Results: All subjects (100%) reported that they had seen some kind of light during the operation. Thirty-eight patients (95%) said that they had seen one or more colors. In 32 patients (80%), the light intensity decreased, and colors blurred significantly following the hydrodissection. As for the pain level during surgery, the overall pain score was found to be 0.40. The highest mean pain score was noted during IOL implantation stage followed by phacoemulsification and bimanual irrigation-aspiration. Conclusion: Topical anesthesia is both a safe and effective method for small-incision clear corneal phacoemulsification cataract surgery. Patients may experience visual sensations, and the pain felt during the operation is low and tolerable. Visual experiences and pain level may change according to the stage of phacoemulsification cataract surgery.

Correlation of retinal sensitivity and retinal thickness in central serous chorioretinopathy.

Aim: To evaluate the correlation of microperimetry (MP) and optical coherence tomography (OCT) in eyes having acute onset of central serous chorioretinopathy (CSCR). Methods: After a detailed ophthalmological examination, all cases were evaluated by fundus fluorescein angiography, OCT and MP. Mean macular thickness was detected by OCT. Mean macular sensitivity (MS) and mean defect (MD) were determined by MP. The correlation between OCT and MP findings was analyzed by Spearman’s correlation test. Results: Fifteen eyes with CSCR of 15 patients with a mean age of 40.5 ± 6.7 years were recruited. The mean visual acuity was 0.7 ± 0.2, and the mean macular thickness was 348.9 ± 75.8 μm. Mean MS and MD were 13.9 ± 4.6 and –5.2 ± 4.1 dB, respectively. The mean macular thickness was significantly correlated with both mean MS and MD (p = 0.011 and p = 0.017, respectively). A significant correlation was also found between mean macualt thickness, MS and MD in the central 1 mm, superior 3 mm and nasal 3 mm of the macula (p < 0.05). Conclusions: Our results demonstrated a significant correlation between structural and functional changes in CSCR. MP provides quantitative measurements of central macular function in CSCR that may supplement OCT findings as well as the better understanding of visual functions during the acute stage of the disease.

Autofluorescence imaging of pingueculae

Aims: To analyse the autofluoresence (AF) properties of pingueculae and compare the size of AF with the extent of the visible lesion. Methods: Forty eyes of 23 patients with pingueculae were included in the study. AF images were obtained using an HRA2 confocal scanning laser ophthalmoscope; anterior segment photographies were obtained using TRC-50IX, IMAGEnet 2000 Digital Imaging System. The AF characteristics of pingueculae were analysed. The extent of visible lesion in anterior segment photography and AF image was compared. Results: AF images revealed well-defined hyper-autofluorescence in the area of pinguecula, which was greater than the extent of visible pinguecula in the slit-lamp examination, in 40 of 56 lesions (71.4%). In none of the eyes was the hyperautofluorescent area smaller than the extent of visible lesion. Conclusion: Pingueculae display hyperautofluorescence in AF imaging. The real size of pingueculae may be estimated by its AF characteristics, which is mostly larger than the visible lesion.

Fundus autofluorescence imaging of macular star.

active retinochoroidal inflammation. Untreated subfoveal CNV secondary to toxoplasmosis is often associated with low VA of 0.2–0.01 (Fine et al. 1981). The results of different therapeutic modalities have been reported in only a few small series, comprising a total of 18 cases (Table 1). Argon laser photocoagulation of subfoveal CNV appeared to be the optimum method with which to stabilize VA. The outcome in VA after subretinal surgery varies considerably. Although V-PDT may stabilize VA, reading vision was achieved in only four of 12 V-PDT-treated eyes. In our case, combined V-PDT and IVTA preserved function for a limited period of 3 months. It remains unclear if photodynamic re-treatment combined with IVTA therapy could have stopped the growth of the reactivated CNV in our patient. We decided to use a different treatment strategy that promised a better chance of preserving the patient’s reading ability. Intravitreal bevacizumab therapy has been reported to have favourable effects in CNV of different inflammatory (e.g. presumed ocular histoplasmosis syndrome [POHS]) and other origins unrelated to age (Teixeira et al. 2006; Adan et al. 2007; Prager et al. 2007). Enhanced expression of vascular endothelial growth factor (VEGF) may be an important feature in inflammatory CNV (Kwak et al. 2000). In our patient, VA increased to normal levels and was preserved until the end of follow-up. We attribute the preservation of VA to the three intravitreal bevacizumab injections and not to previous treatment because VA had decreased following V-PDT but improved shortly after the first bevacizumab injection with scarring of CNV in FA. In conclusion, intravitreal bevacizumab appears to be a beneficial therapeutic option for CNV in toxoplasmosis.

Fundus Autofluorescence in Optic Disc Drusen: Comparison of Confocal Scanning Laser Ophthalmoscope and Standard Fundus Camera

We have evaluated fundus autofluorescence (FAF) imaging in optic disc drusen (ODD). After a detailed ophthalmological examination, 28 eyes of 16 patients were evaluated by FAF imaging using a confocal scanning laser ophthalmoscope and a standard fundus camera. ODD displayed bright nodular autofluorescence. Increased FAF was observed using both the scanning laser ophthalmoscope and the fundus camera. However, high quality images with precise localization of hyaline material at the optic nerve head were only possible using FAF imaging with the confocal scanning laser ophthalmoscope. FAF images obtained using the fundus camera revealed only brightness at the optic nerve head without any detail except when maximum flash intensity was used. We conclude that FAF imaging may be used as a non-invasive, safe and rapid ancillary test for the confirmation of the diagnosis of drusen of the optic disc.

Excitation time dependent increment in the luminescence of Fundus Autofluorescence

Aim: To investigate the excitation-time-dependent increment in luminescence of fundus autofluorescence. Methods: Fundus autofluorescence (FAF) images were obtained with a confocal scanning laser ophthalmoscope. Consecutive 60 images of each eye were taken at 1 s time intervals immediately after the beginning of argon laser excitation. Twenty-one eyes of 21 normal subjects were enrolled in the study. To analyse the luminescence of fundus autofluorescence, an 80×80 pixel square selection was placed in a relatively avascular fundus area of each consecutive image. Individual grey-scale values of the selected areas were recorded, and the time slope was plotted. Results: The time-dependent increment of the autofluorescence was observed in all subjects. The average luminosity value of subjects at the beginning was calculated as 32.5 mean grey value (MGV), and luminosity reached its maximum (45.4 MGV) between 25 and 30 s. Conclusion: The excitation-time-dependent increment in FAF luminosity should be taken into account while acquiring FAF images for quantitative, comparative and longitudinal studies.