Acute effect of cigarette smoking on pupil size and ocular aberrations: a pre- and postsmoking study.

Aim. To evaluate the acute effects of cigarette smoking on photopic and mesopic pupil sizes and wavefront aberrations. Methods. Cigarette smoker volunteers were recruited in the study. Photopic and mesopic pupil sizes and total ocular aberrations were measured before smoking and immediately after smoking. All volunteers were asked to smoke a single cigarette containing 1.0 mg nicotine. Pupil sizes and total ocular aberrations were assessed by optical path difference scanning system (OPD-Scan II ARK-10000, NIDEK). Only the right eyes were considered for statistical analysis. The changes of pupil size and total ocular aberrations after smoking were tested for significance by Wilcoxon signed ranks test. Results. Mean photopic pupil size decreased from 3.52 ± 0.73 mm to 3.29 ± 0.58 mm (P = 0.001) after smoking. Mean mesopic pupil size was also decreased from 6.42 ± 0.75 mm to 6.14 ± 0.75 mm after smoking (P = 0.001). There was a decrease in all the measured components of aberrations (total wavefront aberration, higher-order aberration, total coma, total trefoil, total tetrafoil, total spherical aberration and total higher-order aberration) after smoking; however the differences were insignificant for all (P > 0.05). Conclusion. Our results indicate that pupil constricts after smoking. On the other hand, smoking does not alter ocular aberrations.

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. METHODS: Twelve patients with neovascular age-related macular degeneration and eight patients with diabetic macular oedema were included in the study. All patients received an intravitreal injection of 1.25 mg bevacizumab. Red-free fundus photographs (35°) were acquired with a fundus camera at baseline and one day, one week and one month after the intravitreal injection. Measurements of retinal vessel diameter were made of the supero-temporal retinal venule and arteriole using the software available on the IMAGEnet program. RESULTS: Although there appeared to be a trend towards vasoconstriction for the measurements in the diabetic macular oedema group (both for arterioles and venules at day 7) and the age-related macular degeneration group (for venules at day 1 and for arterioles at day 7), it did not reach statistical significance (p > 0.05). Optical coherence tomography revealed a significant decrease in foveal thickness measurements in both groups at the one month visit compared with baseline. CONCLUSION: The results suggest that intravitreal injection of bevacizumab might induce retinal vasoconstriction; however, low numbers of subjects might have prevented the difference from reaching statistical significance. Further studies with a larger number of subjects would reveal the effect of intravitreal anti-vascular endothelial growth factor treatment on retinal vessel diameters more clearly.

Comparison of non-contact methods for the measurement of central corneal thickness.

BACKGROUND AND OBJECTIVE: This study examined the repeatability of and agreements between central corneal thickness measurements obtained by four different non-contact pachymetry devices. PATIENTS AND METHODS: Seventy-eight eyes of 39 subjects were included. Central corneal thickness of each eye was measured by Visante optical coherence tomography (OCT) (Carl Zeiss Meditec Inc., Dublin, CA), Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany), Orbscan IIz topography (Bausch & Lomb Surgical Inc., San Dimas, CA), and slit-lamp OCT (SL-OCT) (Heidelberg Engineering GmbH, Heidelberg, Germany). Inter-device agreements and correlations and repeatability of each device were examined. RESULTS: All measurement methods correlated well with each other with a correlation coefficient greater than 0.90 and P value of less than .001 for all comparisons. However, Pentacam overestimated central corneal thickness: 546.7 ± 38.2, 535.5 ± 42.7, 531.7 ± 37.6, and 531.2 ± 36.0 µm for Pentacam, Orbscan IIz, Visante OCT, and SL-OCT, respectively (P < .001 for all comparisons versus Pentacam). Despite good correlation, magnitude of differences was high and this bias was proportional (ie, not constant across a range of corneal thickness values) for the following pairs: Orbscan versus Visante OCT, Orbscan versus SL-OCT, and Orbscan versus Pentacam (P < .001 for all comparisons). CONCLUSION: Although measurements obtained by various non-contact methods correlate well, numerical agreement of the results may not be sufficient for their interchangeable use in clinical practice.

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). METHODS: A prospective, cross-sectional, single-centre investigation was performed using three diagnostic techniques, namely, fundus autofluorescence, optical coherence tomography and fundus fluorescein angiography to evaluate a sample of patients (n = 42 eyes) with both acute (n = 25 eyes) and chronic (n = 17 eyes) CSR. RESULTS: Hypoautofluoresecence was found in 80 per cent (20 eyes) and 88.2 per cent (15 eyes) of eyes in the acute and chronic central serous chorioretinopathy groups, respectively, corresponding to the leakage points depicted by fluorescein angiography. Hypoautofluoresence corresponding to the areas of subretinal fluid accumulation was seen in 92 per cent (23 eyes) and 82.3 per cent (14 eyes) of the acute and chronic central serous chorioretinopathy groups, respectively. In two eyes (11.6 per cent) with chronic CSR, hyperautofluorescent changes were noted at the previous leakage points. In the acute CSR group, speckled hyperautofluorescence was detected in nine eyes (36 per cent) after the resolution of subretinal fluid. In the chronic CSR group, simultaneous speckled hyperautofluorescence was detected in the previous areas of subretinal fluid accumulation in 12 eyes (70.5 per cent). CONCLUSION: Fundus autofluorescence imaging delineates endogenous fluorescence derived mainly from lipofuscin within the retinal pigment epithelium (RPE) layer and therefore permits evaluation of functional alterations in the RPE in numerous retinal diseases. Data from fundus autofluorescence revealed distinctive findings in acute and chronic CSR. Fundus autofluorescence imaging may be used as a supplementary diagnostic tool for identifying patients with CSR and differentiation may be made between acute and chronic cases.

Glutathione S-transferase M1, GSTT1 and GSTP1 genetic polymorphisms and the risk of age-related macular degeneration.

PURPOSE: To determine the possible effects of glutathione S-transferase (GST) M1, GSTT1 and GSTP1 genetic polymorphisms on the risk of developing age-related macular degeneration (AMD). PATIENTS AND METHODS: This case-control study included a total of 120 patients with AMD (65 with dry-type AMD and 55 with wet-type AMD) and 198 disease-free controls. GSTM1 and GSTT1 polymorphisms were analyzed by using a multiplex polymerase chain reaction (PCR), and GSTP1 polymorphism was detected by real-time PCR assay. RESULTS: GSTM1-null genotype was significantly associated with the development of AMD (p = 0.01, OR = 1.82, 95% CI = 1.14-2.91). Stratification by AMD subtypes revealed a significant relationship between GSTM1-null genotype and dry-type AMD (p = 0.02, OR = 1.98, 95% CI = 1.10-3.53). In a stepwise regression model, only GSTM1-null genotype was significantly associated with the development of AMD (p = 0.01, OR = 1.77, 95% CI = 1.11-2.81). CONCLUSIONS: Our findings suggest that genetic polymorphisms of GST may have a role in the development of AMD.

Anterior segment optical coherence tomography findings of acute hydrops in a patient with keratoconus.

The authors describe the anterior segment optical coherence tomography (AS-OCT) findings of a 25-year-old patient with acute hydrops associated with keratoconus. The patient presented with decreased visual acuity, pain, and redness in the left eye. The symptoms, clinical presentation, and topographical findings of the right eye confirmed this condition to be acute corneal hydrops. The patient was closely followed up with hyper-osmotic (NaCl 5%) and nonsteroidal anti-inflammatory (ketorolac tromethamine 0.5%) topical treatment. At the initial examination and during follow-up, the evaluation of the anterior segment was performed using optical coherence tomography. Changes in the stroma and Descemet's membrane during the healing process of acute hydrops could be demonstrated by high-resolution AS-OCT.

The importance of lacrimal diaphragm and periosteum suturation in external dacryocystorhinostomy.

PURPOSE: To evaluate retrospectively the cosmetic and functional effects on success of lacrimal diaphragm and periosteum suturation after the anastomosis of anterior flaps before skin closure in external dacryocystorhinostomy (ext-DCR). METHODS: During ext-DCR, lacrimal diaphragm was separated from periosteum over anterior lacrimal crest before entering lacrimal fossa. At the end of ext-DCR, the separated periosteum and lacrimal diaphragm were sutured in the study group (270 patients) and were left unsutured in the age-matched control group (96 patients). The effects of this approach on postoperative appearance of incision area at the 6-month postoperative controls, and functional success (assessed by fluorescein disappearing test) and anatomical success rates (assessed by lacrimal syringing) at the 12-month postoperative controls were evaluated. RESULTS: The anatomic success rate between the 2 groups were found to be similar (94.8% and 92.7% in the study and control groups, respectively, p = 0.447). Fluorescein disappearing test was detected to be normal in 246 patients (91.1%) and 78 patients (81.2%) in the study and control groups, respectively (p = 0.009). Postoperative skin scar was found to develop significantly greater in the control group (p = 0.001). Significant hypertrophic scar was seen in 3 patients (1.1%) and 8 patients (8.3%) in the study and control groups, respectively. No epicanthal fold or webbing occurred in the study group. CONCLUSION: The preservation of the lacrimal sac wall's attachments at the end of ext-DCR to the medial canthal tendon, orbicularis oculi muscle, and lacrimal diaphragm allows the lacrimal pump to function more effectively. Ext-DCR with suturation of the periosteum and lacrimal diaphragm method may provide an excellent functional and aesthetic outcome in the majority of patients.

Assessment of anterior chamber depth using Visante optical coherence tomography, slitlamp optical coherence tomography, IOL Master, Pentacam and Orbscan IIz.

AIMS: To assess and compare the anterior chamber depth (ACD) by different anterior segment imaging techniques. METHODS: Eighty healthy eyes of 40 patients were recruited, and 3 consecutive measurements of ACD were determined prospectively utilizing Visante optical coherence tomography (OCT), slitlamp (SL) OCT, IOL Master, Pentacam and Orbscan IIz. The statistical significance of interdevice differences between measurements was evaluated by one-way ANOVA and Bland-Altman analysis. The repeatability of 3 consecutive measurements was analyzed by repeated-measures ANOVA. RESULTS: The mean ACD was 2.98 ± 0.29, 2.85 ± 0.29, 3.33 ± 0.42, 2.93 ± 0.30 and 2.80 ± 0.29 mm with Visante OCT, SL-OCT, IOL Master, Pentacam and Orbscan IIz, respectively. All devices displayed a high intrasession repeatability (repeated-measures ANOVA, p > 0.05). ACD measurements obtained by the IOL Master were significantly greater compared to other devices. ACD values detected by Visante OCT and SL-OCT, Pentacam and Orbscan IIz were not clinically interchangeable, even though no statistically significant difference was detected. CONCLUSION: Although noncontact ACD measurements using all modalities were easy to handle and demonstrated good repeatability, the tested devices were not regarded as compatible. Hence, the clinician should take the different modalities into consideration during ACD assessment using various devices.

Multifocal electroretinogram and central visual field testing in central areolar choroidal dystrophy.

PURPOSE: To study multifocal electroretinogram (mfERG) and its relation to retinal sensitivity assessed by Humphrey visual field (HVF) analysis in central areolar choroidal dystrophy (CACD). METHODS: Seven eyes of 4 patients with CACD and 15 normal control subjects were examined. mfERG and central 30/2 HVF were tested for each participant. Ring analysis in mfERG was evaluated. HVF results were evaluated in 5 concentric rings in order to compare the results to concentric ring analysis in mfERG. The differences between control subjects and patients were evaluated by Mann-Whitney U test and the correlations were assessed by Spearman test. RESULTS: Mean Snellen acuity was 0.49+/-0.10 in patients. HVF revealed central scotoma in 6 of 7 eyes (85.7%), whereas a paracentral scotoma extending to fixation point was detected in 1 eye. The retinal sensitivities in 5 concentric rings in HVF were significantly lower (p<0.001 for ring 1 to ring 4, and p=0.017 in ring 5) in CACD patients. Similarly, CACD patients had lower P1/N1 amplitudes (p<0.05) and delayed P1/N1 implicit times (p<0.05). CONCLUSIONS: In CACD, in the areas of scotoma detected by HVF, mfERG values were depressed. However, both mfERG and HVF abnormalities were found outside the areas of ophthalmoscopically normal retinal areas.

Assessment and comparison of anterior chamber dimensions using various imaging techniques.

BACKGROUND AND OBJECTIVE: To assess and compare the horizontal dimensions of the anterior chamber by different anterior segment imaging techniques. PATIENTS AND METHODS: Eighty eyes of 40 patients without any ocular disease or previous ocular surgery were recruited and three consecutive measurements of internal anterior chamber diameter and white-to-white distance (WTW) parameters were determined. RESULTS: Mean internal anterior chamber diameter was 11.80 +/- 0.39, 11.56 +/- 0.47, and 11.61 +/- 0.58 mm with Visante-OCT, SL-OCT, and Pentacam, respectively. Mean WTW distance was 11.87 +/- 0.35 and 11.65 +/- 0.32 mm by IOLMaster and OrbscanIIz, respectively. There was no significant difference between Visante-OCT and Pentacam, IOLMaster, and OrbscanIIz (P = .125, .918, and .314). However, detection of mean internal anterior chamber diameter was significantly greater by Visante-OCT than SL-OCT (P = .026). All devices displayed a high intrasession repeatability (repeated measured ANOVA, P > .05). CONCLUSION: Internal anterior chamber diameter measurements using Visante-OCT, SL-OCT, and Pentacam, and WTW measurements using IOLMaster and OrbscanIIz were easy to handle and demonstrated good repeatability. Although similar results of horizontal anterior chamber diameter were determined by Visante-OCT, Pentacam, IOLMaster, and OrbscanIIz, the inter-device differences should be considered during clinical practice.

Changes in intraocular pressure, and corneal and retinal nerve fiber layer thickness during hemodialysis.

The aim of this study is to evaluate the changes in intraocular pressure (IOP), central corneal thickness (CCT), and retinal nerve fiber layer thickness (RNFLT) in patients with chronic renal failure undergoing hemodialysis (HD). A complete ophthalmological examination together with IOP, CCT, and RNFLT measurements were performed for each patient both before and after HD sessions. RNFLT parameters were detected by scanning laser polarimeter. Total body weight and serum osmolality were also measured. Only the left eyes were recruited for statistical analysis. Thirty-three eyes of 33 patients were enrolled in the study. Mean IOP decreased from 14.7 +/- 3.1 to 13.4 +/- 2.4 mmHg after HD (paired t test, P = 0.005). Mean CCT also decreased significantly after HD, from 556.5 +/- 33.5 to 550.2 +/- 34.6 mum (paired t test, P = 0.002). CCT change in the left eyes was found to be correlated with total body volume loss (Pearson correlation test, R = 0.391 and P = 0.030). Considering RNFLT parameters before and after HD, no significant alterations were detected by scanning laser polarimeter (paired t test, P > 0.05). We conclude that IOP may decrease to some extent after HD. CCT may be affected by fluid loss after HD sessions, with a resultant decrease in corneal thickness. In patients with chronic renal failure undergoing HD, RNFLT parameters can be measured as in healthy individuals. Underestimation of intraocular pressure values after HD sessions should be taken into account, especially in patients with chronic renal failure.

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 mum. 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 macular 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.

Diurnal variation of corneal biomechanics and intraocular pressure in normal subjects.

PURPOSE: To assess and investigate the relationship between diurnal variations in intraocular pressure (IOP) and biomechanical properties of cornea. METHODS: Sixty-two healthy volunteers were recruited. Corneal compensated IOP (IOPcc), Goldmann-correlated IOP (IOPg), corneal resistance factor (CRF), and corneal hysteresis (CH) parameters were recorded by the Ocular Response Analyzer (ORA). Central corneal thickness (CCT) was measured using an ultrasonic pachymeter. Three consecutive measurements of IOPcc, IOPg, CRF, CH, and CCT were recorded at 8:00 am, 11:00 am, 2:00 pm, and 5:00 pm. One-way analysis of variance and Pearson correlation tests were used for statistical analysis. Intra device repeatability was evaluated using Scheffe multiple comparison. RESULTS: IOPcc, IOPg, CRF, CH, and CCT measurements displayed a stable profile during daytime acquisitions and no statistically significant variation was noted (p>0.05). All measurements of IOPcc, IOPg, CRF, and CH recorded by ORA at 8:00 am, 11:00 am, 2:00 pm, and 5:00 pm were all found to be highly repeatable (p>0.05). There was a statistically significant and inverse correlation between IOPcc and CH (p=0.001), and a positive correlation was detected between IOPcc and CRF (p=0.001). CRF and CH were both found to be positively correlated to CCT (p=0.001). CONCLUSIONS: IOPcc readings and recordings of corneal biomechanics were constant throughout the day in healthy eyes. CRF and CH seem to exert different effects on IOPcc as diverse correlations were detected between CRF, CH, and IOPcc. Assessment of IOP and corneal biomechanics using ORA was found to be a highly repeatable.

Immediate evaluation of the flaps created by femtosecond laser using anterior segment optical coherence tomography.

BACKGROUND AND OBJECTIVE: To demonstrate the practical and functional evaluation of flaps created intraoperatively by femtosecond laser using anterior segment optical coherence tomography (AS-OCT). PATIENTS AND METHODS: The study prospectively examined 11 eyes of 6 patients who underwent uneventful LASIK surgery with the aid of the IntraLase femtosecond laser (IntraLase Corp., Irvine, CA). During the waiting period between femtosecond laser and excimer laser, all eyes were evaluated by AS-OCT to image each flap immediately before flap lifting and laser ablation. Flap thickness and residual stromal bed thickness were calculated automatically using the software's flap tool. RESULTS: A uniform flap was created by femtosecond laser not only in the central cornea, but also in all quadrants. CONCLUSION: The qualitative and quantitative evaluation of the corneal flap created by a femtosecond laser using AS-OCT before lifting the flap confirms that the femtosecond laser is a practical intraoperative approach that offers a safer surgery.

Anterior segment optical coherence tomography measurement of anterior chamber depth and angle changes after phacoemulsification and intraocular lens implantation.

PURPOSE: To use anterior segment optical coherence tomography (AS-OCT) to evaluate anterior chamber depth (ACD) and angle after phacoemulsification and intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, Yeditepe University, Istanbul, Turkey. METHODS: Forty-seven eyes (37 patients) had uneventful phacoemulsification and IOL implantation through a clear corneal incision. Anterior segment OCT was performed preoperatively and 1 week and 1 month postoperatively. The angle-referenced (ACD(1)), pupil-referenced (ACD(2)), and lens-referenced (ACD(3)) ACDs, crystalline lens rise (CLR), pseudophakic posterior chamber depth (PPCD), and nasal and temporal iridocorneal angles were measured. Statistical analysis was by a 1-way analysis of variance and Pearson correlation analysis. RESULTS: The mean age of patients was 70 years+/-10.17 (SD). The mean ACD(1) (mean increase) was 3.06+/-0.25 mm preoperatively, 3.16+/-0.22 mm at 1 week (0.1 mm), and 3.16+/-0.19 mm at 1 month (0.1 mm); the mean ACD(2), 2.76+/-0.47 mm preoperatively, 3.62+/-0.24 mm at 1 week (0.86 mm), and 3.63+/-0.20 mm (0.87 mm) at 1 month; and the mean ACD(3), 2.54+/-0.46 mm preoperatively, 3.97+/-0.28 mm at 1 week (1.43 mm), and 3.91+/-0.25 mm at 1 month (1.37 mm). The mean CLR was 0.497+/-0.363 mm and the mean PPCD, 0.322+/-0.150 mm. The increase in nasal and temporal iridocorneal angles was statistically significant at both postoperative examinations (P<.01). CONCLUSION: Deepening of the anterior chamber and widening of the nasal and temporal angles after cataract extraction was shown on AS-OCT.

Atypical presentation of multiple evanescent white dot syndrome (MEWDS).

PURPOSE: To present fundus autofluorescence (FAF), indocyanine green angiography (ICGA), and microperimetry (MP) findings of a patient with multiple evanescent white dot syndrome (MEWDS). METHODS: Observational case report. RESULTS: A 30-year-old woman with blurry vision was referred for evaluation. Fundus examination revealed only foveal granularity. FAF showed hyperautofluorescent spots, although they were not visible clinically. On ICGA, matching areas were hypofluorescent. Microperimetry revealed mean sensitivity decrease. The resolution of the symptoms was followed by disappearance of these spots in FAF and ICGA and increase of mean macular sensitivity in MP. CONCLUSION: FAF is a noninvasive imaging technique that might help in the differential diagnosis of chorioretinal pathologies.

Treatment of cystoid macular edema due to acute posterior multifocal placoid pigment epitheliopathy.

PURPOSE: To report a case of unilateral late-presenting acute posterior multifocal placoid pigment epitheliopathy (APMPPE) with CME evaluated before and after administration of IVTA. METHOD: A 29-year-old male diagnosed as APMPPE with CME was treated with IVTA. RESULTS: Fundus examination revealed CME and sequelae APMPPE lesions without involvement of posterior pole. FA and OCT findings were consistent with CME. After IVTA (4 mg/0.1 mL) administration; BCVA increased from 20/28 to 20/20, mean retinal thickness decreased in OCT, and mean sensitivity in microperimetry increased from 15.7 to 17.2 dB. CONCLUSION: In this case report, IVTA improved macular anatomy, visual acuity, and macular sensitivity.