Optical coherence tomography angiography findings in optic disc drusen and idiopathic intracranial hypertension.

PURPOSE: To evaluate the changes in peripapillary microvascularity in idiopathic intracranial hypertension (IIH) and optic disc drusen (ODD) patients, by comparing them with those in healthy individuals, via optical coherence tomography angiography (OCTA). METHODS: Sixty-two eyes of 33 patients with ODD, 58 eyes of 30 patients with IIH, and 70 eyes of 70 healthy people were imaged for 6 × 6-mm optic disc scans on a spectral-domain OCTA. Vascular densities in superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) of ODD, IIH, and healthy eyes were compared with a one-way analysis of variance. Post-hoc analysis was performed with the Gabriel test. RESULTS: There was a significant decrease in peripapillary vessel density in SCP, DCP, and CC in patients with IIH compared to the control group (p < 0.05). In ODD patients, especially peripapillary vessel density in DCP was significantly reduced compared to the control group (p < 0.05). Peripapillary vessel density in DCP was significantly lower in the IIH group than ODD group (p < 0.05). CONCLUSIONS: Peripapillary vascular density may be affected during the course of the disease in both IIH and ODD. Compared to healthy individuals, the decrease in vascular density in these patients and the consequent decrease in perfusion in the peripapillary region may guide the pathogenesis of the complications in the course of these two diseases. Although vascular density in DCP and CC differs significantly between IIH and ODD, case-controlled studies are needed to evaluate the role of OCTA in the differential diagnosis of IHH and ODD.

Changes in intra-ocular pressure, ocular pulse amplitude and choroidal thickness after trabeculectomy.

CLINICAL RELEVANCE: Glaucoma is one of the most common causes of blindness. Although high intra-ocular pressure (IOP) is the most important risk factor, ocular blood flow also has an effect on prognosis. BACKGROUND: The aim of this study was to investigate the IOP, ocular pulse amplitude (OPA) and choroidal thickness (CT) changes after trabeculectomy and to determine whether trabeculectomy has an effect on ocular blood flow. METHODS: This retrospective, comparative case series was conducted with 33 eyes of 33 patients who underwent trabeculectomy due to uncontrolled glaucoma. The fellow eyes of 20 patients who were followed up with medical therapy were included as a control group. IOP and OPA were evaluated using a dynamic contour tonometer. Subfoveal choroidal thickness (SFCT) was obtained with enhanced depth imaging (EDI) mode of Spectralis-OCT. RESULTS: The mean IOP was 21.6 ± 6.3 mmHg at baseline and 13.8 ± 0.9 mmHg after trabeculectomy (p ˂ 0.001), and the mean OPA was 4.1 ± 1.5 at baseline and 2.6 ± 1.6 mmHg after trabeculectomy (p ˂ 0.001). The mean SFCT was 292.2 ± 63.2 µm at baseline and 303.8 ± 70.4 µm after trabeculectomy (p = 0.024). The change in OPA was strongly positively correlated with the change in IOP (r = 0.597, p ˂ 0.001) and SFCT change was positively correlated with OPA change (r = 0.34, p = 0.05). There was no difference between the two groups in terms of IOP, OPA and SFCT values measured after trabeculectomy (respectively, p = 0.264, p = 0.627 and p = 0.949). CONCLUSION: The large IOP decrease following trabeculectomy causes a decrease in OPA and choroidal thickening. On the other hand, trabeculectomy has no effect on OPA change.

Comparison of corneal, endothelial, and anterior segment parameters in eyes with and without pigment dispersion.

BACKGROUND: To evaluate the differences of central corneal thickness (CCT), corneal endothelial cell morphology, and biometric parameters of the anterior chamber and iridocorneal angle in pigment dispersion syndrome (PDS), pigmentary glaucoma (PG), primary open-angle glaucoma (POAG), and healthy group. METHODS: Twenty- three eyes in the PDS group, 39 eyes in the PG group, 33 eyes in the POAG group, and 45 eyes in the healthy control group were included in this cross-sectional retrospective study. Corneal endothelial cell density, the coefficient of variation in the cell area, hexagonality, and central corneal thickness (CCT) were obtained by specular microscopy (CEM 530, NIDEK, Japan). Anterior chamber depth (ACD), iridocorneal angle parameters and CCT were measured by anterior segment optical coherence tomography (AS-OCT) (Visante OCT, Carl Zeiss AG, Germany). RESULTS: The mean CCT via specular microscopy (SM-CCT) was measured at the thinnest value in the PG group (531.20 ± 34.91 µm) and the thickest in the control group (569.13 ± 37.52 µm). CV value was higher in PG (34.65 ± 6.84) and POAG group (34.27 ± 9.93) and lower in control group (28.82 ± 5.18) (p = 0,005). The mean AS-OCT-CCT was the thinnest in the PG group (513.61 ± 39.94 µm), and the thickest in the control group (547.04 ± 36.72 µm) (p = 0.001). All parameters of the iridocorneal angle were larger in the PDS and PG groups (p < 0.001). In the correlation analysis of the glaucomatous eyes, a negative correlation between the C/D ratio and SM-CCT and AS-OCT-CCT (p = 0.037, p = 0.017, respectively) and a positive correlation between the pRNFL thickness and AS-OCT- CCT (p = 0.002). CONCLUSION: CCT values obtained with both SM and AS-OCT were found to be significantly thinner in PG cases. CV, which is the measure of polymegatism, was found to be significantly higher in PG cases.

Surgical management of glaucoma following different keratoplasty techniques.

PURPOSE: To investigate the results of surgical management of glaucoma following different keratoplasty techniques. METHODS: Medical records of 628 cases who underwent keratoplasty were reviewed. One hundred and eighty-eight patients (29.9%) who developed post-keratoplasty glaucoma were evaluated. Patients who could not be controlled with maximal medical treatment and underwent glaucoma surgery were included in this study. Trabeculectomy, Ahmed glaucoma valve (AGV) implantation or diode laser cyclophotocoagulation (DLC) were applied. RESULTS: Glaucoma surgery was performed in 55 (29.3%) patients who had uncontrolled post-keratoplasty glaucoma. In penetrating keratoplasty group (n = 42), DLC was applied to 30 (71.4%) eyes, AGV to 11 (26.2%) eyes, and trabeculectomy in 1 (2.4%) eye. In Descemet's membrane endothelial keratoplasty group (n = 8), DLC was applied to 4 (50%) eyes, trabeculectomy for 3 (37.5%) eyes and AGV for 1 (12.5%) eye. In deep anterior lamellar keratoplasty group (n = 5), DLC was applied to 2 (40%) eyes, trabeculectomy to 2 (40%) eyes and AGV to 1 (20%) eye. While a statistically significant decrease was found in intraocular pressure (IOP) and anti-glaucomatous medication after surgery (p < 0.05 for each), no significant difference was found in best corrected visual acuity (BCVA). During follow-up, DLC was applied as re-glaucoma surgery in 19 (34.5%) cases. A significant reduction in IOP together with number of anti-glaucomatous medications was found with re-operation; however, a significant decrease in BCVA was noted (p < 0.05 for each). CONCLUSION: Glaucoma surgeries after keratoplasty are effective in decreasing IOP and the number of anti-glaucomatous medication. While BCVA doesn't change after the first glaucoma surgery, after re-operation significant decrease may occur.

Anterior chamber laser flare photometry after diode laser cyclophotocoagulation.

BACKGROUND: The aim of this study was to evaluate changes in intraocular inflammation according to energy delivered per eye during transscleral diode laser cyclophotocoagulation (TDLC) in refractory glaucoma using laser flare (LF) photometry and to investigate the relationship between the change in anterior chamber flare values ​​and the success of TDLC. METHODS: Patients who underwent TDLC for refractory glaucoma and had LF photometry data were analyzed retrospectively. We recorded the best-corrected visual acuity, intraocular pressure (IOP) with Goldmann applanation tonometer, number of anti-glaucoma medications, LF photometry values (ph/ms) on pre-and postoperative days 1, 10 and 30. RESULTS: The mean laser power applied during TDLC procedure was 2.45±0.35 W. The mean laser duration was 2.09±0.28 s. The mean total energy applied per eye was 114.69±16.13 J, the mean number of pulses was 22.43±4.3. While the mean LF value was 49.71±11.99 ph/ms preoperatively, it was 63.94±12.41 ph/ms at the postoperative 30th day. Possible predictors of success of TDLC were investigated using linear regression analysis (R adjusted 0.454 p = 0.001). The IOP decrease at postoperative 30th day was significantly related to the difference between the postoperative 1st day and the preoperative LF (p = 0.025, B/95% CI -0.358/-0.107- -0.008), and total cyclodiode energy delivered per eye (joules) (p = 0.016, B/95% CI -0.396/-0.287 to -0.031). CONCLUSIONS: Anterior chamber flare values increases after TDLC, though it does not regress to the preoperative level on the postoperative 30th day. Total cyclodiode energy delivered per eye and the difference between the postoperative 1st day and the preoperative LF can be used to predict TDLC response.

Non-intraocular pressure-related revision surgeries after Ahmed glaucoma valve (AGV) implantation in refractory glaucoma.

PURPOSE: Ahmed glaucoma valve (AGV) is an effective treatment method for refractory glaucoma (RG), however, additional surgical interventions may be required over the course of follow-up due to complications. Our aim is to investigate the causes, types, and outcomes of revisional surgical interventions apart from revisions aiming IOP control, following AGV implantation in patients with RG. METHODS: The pre- and postoperative month 1-3-6-12 and last visit examination findings of the patients who underwent various surgical revisions of AGV between January 2015 and April 2018 in our clinic were recorded, as well as the interval between AGV implantation-revision surgery and the presence of any other complications necessitating additional surgery. The success criteria were defined on the basis of need for additional procedures. RESULTS: Twenty-six eyes of 24 patients were included. The follow-up time and the interval between AGV implantation-surgical revisions were median 12 (6-92) and median 9.7 (1-72) months, respectively. The most common complication requiring revision was tube exposure in 15 (57.7%) followed by tube malposition in 11 (42.3%) eyes. Further interventions were required only in one eye with recurrent exposure. CONCLUSION: AGV implantation has early and late tube-related complications necessitating revisional surgical interventions; which makes it important to have extended follow-up period for patients with AGV implants. Revisional interventions for AGV implants with tube-related complications are efficient procedures for the majority of patients, but recurrence may occur requiring additional revisions.

Pressure restoration and visual recovery time in hypotony after trabeculectomy.

OBJECTIVES: To asses the course of intraocular pressure (IOP) restoration and visual acuity (VA) recovery in eyes with hypotony after trabeculectomy. METHODS: Medical charts of patients undergoing trabeculectomy between January 2017 and June 2019 were reviewed. Cases with hypotony (IOP < 5 mmHg) due to over-filtration in the early postoperative period were assessed retrospectively. Primary outcome measures included change in IOP and VA in the postoperative period and percentage of eyes with hypotony on each follow-up. RESULTS: Thirty-five eyes of 31 patients (23 male, 8 female) were included. The mean follow-up was 18.3 ± 6.9 months. The mean IOP was 3.0 ± 3.2, 9.2 ± 6.2, 9.4 ± 5.6, 9.4 ± 4.0, 10.9 ± 3.6 and 10.2 ± 3.3 mmHg at week 1, months 1, 3, 6, 12 and last follow-up, respectively. Out of 35 hypotonic eyes, 8 (22.8%) had prolonged hypotony at month 1, 4 (11.4%) at month 3, 1 (2.9%) at month 6. The decrease in VA continued to be significant at months 1 and 3 (p = 0.015, p = 0.036, respectively) and returned to baseline after the sixth month (p > 0.524). CONCLUSIONS: In eyes with early hypotony after trabeculectomy while low IOP recovers at first month, it takes longer for the visual restoration. The postoperative month 1 appears to be decisive for recovery of hypotony.

Analysis of the Peripapillary Choroidal Vascular Characteristics in Papilledema Associated with Pseudotumor Cerebri.

SIGNIFICANCE: Choroidal vascularity index measured by image binarization method from peripapillary optical coherence tomography sections has been found significantly lower in papilledema patients than healthy controls. PURPOSE: The purpose of this study was to compare peripapillary choroidal parameters in papilledema patients with control subjects. METHODS: Peripapillary spectral domain optical coherence tomography scans of 34 patients with papilledema and 34 healthy controls are acquired for the study. Images are binarized with the ImageJ software (National Institutes of Health, Bethesda, MD) to calculate total choroidal area, stromal area, luminal area, and choroidal vascularity index. RESULTS: Total choroidal area, luminal area, and choroidal vascularity were significantly lower in papilledema patients compared with healthy controls on right (1.343 ± 0.286 vs. 1.694 ± 0.344, P < .001; 0.880 ± 0.209 vs. 1.167 ± 0.255, P < .001; 65.28 ± 2.99% vs. 68.68 ± 2.81%, P < .001, respectively) and left eyes (1.376 ± 0.308 vs. 1.647 ± 0.339, P < .001; 0.899 ± 0.231 vs. 1.134 ± 0.237, P < .001; 64.92 ± 3.44 vs. 68.84 ± 3.23, P < .001, respectively). No difference was found between active and remitted stages of papilledema in terms of choroidal parameters. CONCLUSIONS: Peripapillary total choroidal area, luminal area, and choroidal vascularity index are significantly reduced in patients with papilledema. These parameters might be beneficial tools for evaluating choroidal vascularity in papilledema quantitatively and differential diagnosis for optic disc edema.

Evaluation of Diplopia Secondary to Seton Implantation Surgery: Ahmed Glaucoma Valve and Diplopia.

Objectives: To determine and evaluate the rate of diplopia after Ahmed glaucoma valve (AGV) implantation surgery. Materials and Methods: The records of patients who underwent AGV implantation in our hospital between the years of 2010 and 2017 were retrospectively reviewed. Patients who were referred to our strabismus department due to binocular diplopia after AGV implantation surgery were included. The details of postoperative day 1, day 7, day 15, and 1 month examinations were recorded. In the postoperative period, the onset time of diplopia complaints, diplopia type, and the presence of diplopia at distance and near fixation were noted. Ocular motility examination and deviation measurements were evaluated. Results: Ten (47%) of 211 patients who underwent AGV implantation in our hospital between 2010 and 2017 met the study inclusion criteria. Six of the 10 patients were men (60%) and 4 were women (40%). The mean age of the patients was 44.5 (34-63) years. Complaints of diplopia developed at a mean of 14.5±12.3 (1-30) days after AGV implantation. The prism measurements of the patients were found to be 8.4±1.4 prism diopters (PD) exotropia and 7.1±8.8 PD hypotropia. While 8 patients had diplopia only at near distance, 2 patients had diplopia at both distance and near. Three patients were treated with prismatic glasses, and their complaints of diplopia recovered spontaneously in 5.11±4.10 months. The other 7 patients were followed up without treatment, and their diplopia complaints resolved spontaneously in 6.11±4.40 months. Conclusion: Although most of the diplopia that develops after AGV implant surgery resolves without treatment, prismatic glasses might be considered as a treatment option in patients whose diplopia affects their daily lives.

Effect of phacoemulsification surgery on intraocular pressure and function of bleb after trabeculectomy.

PURPOSE: To evaluate the effect of phacoemulsification (PE) surgery on intraocular pressure (IOP) control and morphology of filtering bleb in eyes that have previously had trabeculectomy in the long-term. METHODS: This retrospective study included 98 eyes of 93 patients who had undergone trabeculectomy first and then PE surgery. The IOP, morphology of bleb, the number of glaucoma medication of each patient before PE, and 1 day, 1 month, 3 months, 1 year, 2 years after PE, and at the last visit were recorded. The need for additional glaucoma medication or glaucoma surgery were noted. Surgical success was defined as 6 mmHg ≤ IOP ≤ 21 mm Hg at the 3rd month, 1st year, and 2nd year follow-up visit, without additional medication or surgery. RESULTS: Before PE the IOP was ≤ 21 mmHg in all of the eyes. At the last visit, the IOP was ≤ 21 mmHg in 6 eyes with fewer glaucoma medication, in 24 eyes with the same number, and in 36 eyes with more. There was an increase in the number of glaucoma medications on each visit (p < 0.05). There was a statistically significant difference in bleb morphologies between before PE and each visit after PE (p < 0.001). Surgical success after PE was obtained in 52 eyes, additional glaucoma medication was needed in 36 eyes, and additional surgical procedures were required in 14 eyes. CONCLUSION: Phacoemulsification surgery may increase the number of glaucoma medications and the mean IOP and also may reduce the function of bleb in eyes that underwent trabeculectomy.

Do We Conform with European Glaucoma Society Guidelines in the Medical Treatment of Primary Open-Angle Glaucoma/Ocular Hypertension? Data from a Real-Life Practice.

Purpose: To evaluate the prescribing habits of glaucoma specialists and of general ophthalmologists, and reveal the conformance with European Glaucoma Society (EGS) guidelines in the medical treatment of primary open-angle glaucoma (POAG) and ocular hypertension (OHT). Methods: Patients receiving medical treatment for POAG/OHT in the glaucoma clinic comprised the "naive group." Patients having a diagnosis and a treatment for POAG/OHT initiated in another center before presentation comprised the second group and were named as "treatment initiated elsewhere" (TIEW). All patients were retrospectively evaluated from the patients' charts. The outcome measures included the percentage of eyes treated with monotherapy, the molecule groups preferred, and the change in prescription trends over the years in both groups. Results: Seventy-two subjects were included in the naive group and 135 subjects in TIEW group. The rate of monotherapy was 76% and 36% in both groups, respectively. The molecule number was significantly higher in the TIEW group compared with naive group (1.98 ± 0.89 vs. 1.28 ± 0.56, P < 0.001). Until 2003, beta blockers, and in the 2003-2008 period, prostaglandin analogs (PGAs) were the mostly prescribed drugs in glaucoma clinic. From 2009, the rate of PGAs declined, with PGAs being replaced by combination drugs and alfa-2 agonists. Conclusions: Overtreatment rate was high among patients receiving a diagnosis and a treatment by general ophthalmologists, whereas glaucoma specialists were found to conform with EGS guidelines. A shift toward polypharmacy was observed from 2000 to 2017. The common guidelines to evaluate and treat glaucoma need to be adopted by the general ophthalmologists in their real-life practice.

Comparison of the lamina cribrosa parameters in eyes with exfoliation syndrome, exfoliation glaucoma and healthy subjects.

PURPOSE: This study aimed to compare lamina cribrosa (LC) parameters obtained by spectral-domain optical coherence tomography (SD-OCT) of eyes with exfoliation syndrome (PXS), exfoliation glaucoma (PXG) and healthy subjects. METHODS: In this cross-sectional comparative study, 206 eyes of 206 subjects were included. The Bruch's membrane opening distance (BMOd), the anterior and posterior borders of the LC (LC thickness) and the anterior laminar depth (ALD) were imaged using the enhanced depth imaging (EDI) mode of SD-OCT. RESULTS: There were 96 eyes in the PXG group, 55 eyes in the PXS group, and 55 eyes in the control group. The LC thickness was the thinnest in the PXG group (151.10 ± 51.18 µm), followed in the PXS group (158.76 ± 49.62 µm), and the thickest in the control group (181.00 ± 39.10 µm) (p = 0.002). In PXG cases where LC was observed in the deepest location, the ALD value was highest (423.92 ± 111.75 µm) in the PXG group, followed by the control group (403.08 ± 63.56 µm), and PXS group (357.43 ± 80.87 µm) (p < 0.001). The BMOd values were largest in the PXG group (1542.43 ± 152.99 µm), followed by the control group (1506.52 ± 169.09 µm) and PXS group (1435.74 ± 141.06 µm) (p < 0.001). In the PXG group, peripapillary retinal nerve fiber layer (pRNFL) thickness, BCVA, and cup to disc (C/D) ratio were also statistically different from the other groups (p < 0.001). CONCLUSION: We found thinner LC thickness in PXG and PXS cases relative to the control group. Although its severity is associated with the diagnosis and severity of glaucoma, LC thinning can be encountered as an isolated condition in the presence of exfoliation.

Ultrasound Biomicroscopic Evaluation of Anterior Segment Parameters and Surgical Area Following Trabeculectomy Surgery.

OBJECTIVES: This study used ultrasound biomicroscopy (UBM) imaging to evaluate the anterior segment structure and surgical area of patients with open angle glaucoma following a trabeculectomy procedure. METHODS: Consecutive patients with primary open angle or pseudoexfoliative glaucoma who underwent a trabeculectomy were included. UBM was used to examine the anatomical parameters of anterior chamber depth, anterior chamber angle, angle opening distance at 500 µm (AOD500), trabecular ciliary process distance (TCPD), iris ciliary process distance, scleral ciliary process angle (SCPA), and ciliary process thickness, as well as the internal ostium opening, ostium-iris distance, and scleral flap dimensions. Bleb morphologies were evaluated qualitatively using the Yamamoto classification and quantitatively according to the presence of drainage from the medial, lateral, and posterior borders. RESULTS: Twenty-five eyes of 23 patients (4 female, 19 male) were included in the study. The TCPD and SCPA measurements were significantly greater in the postoperative third month (1.04±0.12 mm vs 1.09±0.16 mm, p<0.05; 58.6±3.9° vs 60.8±3.8°, p<0.05, respectively). Cases with a longer ostium-iris distance had a significantly greater AOD500, TCPD, and SCPA (p<0.05). Bleb drainage and morphological classification were correlated (p=0.001). CONCLUSION: UBM is a sound and efficient method to investigate anterior segment variations and the surgical bleb following a trabeculectomy. TCPD and SCPA values increased after surgery.

Serum Vitamin D Level and Body Mass Index in Children with Vernal Keratoconjunctivitis.

OBJECTIVES: The purpose of this study was to evaluate the body mass index (BMI) value and serum 25-hydroxyvitamin D [25(OH)D3] level in children with vernal keratoconjunctivitis (VKC). METHODS: A total of 40 healthy, non-atopic children (control group) and 46 children with VKC (study group) were included in the study. The serum vitamin D [25(OH)D3] levels and BMI values were measured and compared between the 2 groups. RESULTS: The mean vitamin D level measured in the healthy children (mean: 19.01±5.66 ng/mL, range: 9-33.09 ng/mL) was significantly different from the mean vitamin D level in the VKC-affected children (mean: 14.06±5.02 ng/mL, range 4.37-31 ng/mL) (p<0.001). The mean BMI in the VKC group (17.1±2.5 kg/m2) was significantly higher than the mean BMI of the healthy children (mean: 16.5±2.3 kg/m2; p=0.046). A negative correlation (Spearman's rho=-0.275; p=0.01) was observed between the vitamin D level and the BMI value. CONCLUSION: The results indicated that children with VKC had a lower serum vitamin D level and a higher BMI value compared with healthy, age- and sex-matched children.

Morphological assessment of lamina cribrosa in idiopathic intracranial hypertension.

Purpose: Technological development of optic coherence tomography has enabled a detailed assessment of the optic nerve and deeper structures and in vivo measurements. The aim of this study was to compare the lamina cribrosa morphology of the optic nerve in idiopathic intracranial hypertension (IIH) and healthy individuals. Methods: The lamina cribrosa morphology of optic nerve in 15 eyes with IIH and 17 eyes of healthy individuals were compared. Four parameters such as Bruch membrane opening (BMO), lamina cribrosa thickness (LCT), prelaminar tissue thickness (PTT), and anterior lamina cribrosa surface depth (ALCSD) were retrospectively evaluated. Results: By enhanced depth imaging-optic coherence tomography (EDI-OCT), PTT and BMO were found to be significantly greater (574,35 ± 169,20 µm and 1787,40 ± 140,87 µm, respectively) in IIH patients than healthy individuals (187,18 ± 132,15 µm and 1632,65 ± 162,58 µm, respectively), whereas ALSCD was found to be significantly less in IIH patients (234,49 ± 49,31 µm) than healthy individuals (425,65 ± 65,23 µm). There was not a statistically significant difference regarding LCT between the IIH patients (238,59 ± 17,31 µm) and healthy individuals (244,96 ± 15,32 µm). Conclusion: Increased intracranial pressure causes morphological changes in lamina cribrosa. Assessment of lamina cribrosa with EDI-OCT is important for diagnosis and follow-up of patients with IIH. EDI-OCT is objective, reproducible, and cost-effective assistive imaging tool in IIH patients.

Comparison of the Lamina Cribrosa Measurements Obtained by Spectral-Domain and Swept-Source Optical Coherence Tomography.

Purpose/Aim of the study: The aim of this study was to compare the lamina cribrosa (LC) measurements obtained by Spectral-Domain Optical Coherence Tomography (SD-OCT) and Swept-Source Optical Coherence Tomography (SS-OCT) in the same eye and we also investigate how the differences in measurement will change in the presence of pseudoexfoliation glaucoma (PEG). Materials and Methods: A total of 30 patients from one institution have accepted. Detailed medical case histories and clinical examination, optic nerve head imaging using the SD-OCT (Heidelberg Engineering, Heidelberg, Germany) and SS-OCT (Triton; Topcon Medical Systems, Tokyo, Japan) for patients with pseudoexfoliation glaucoma and healthy volunteer. Results: Fifty-three eyes of the 30 patients (13 female, 17 male) were included in the study. Twenty-nine of eyes were healthy and 24 of eyes had pseudoexfoliation glaucoma. The mean age was 62 ± 7.3 years (range, 50-86 years). The difference between the mean Bruch's membrane opening distance measured by SD-OCT (1504.7 ± 154.2 µm) and by SS-OCT (1568.6 ± 193.3 µm) was statistically significant (p = .009). The difference between LC depth and LC thickness measurements between two OCT devices were not statistically significant. There was a negative correlation between the difference of two devices Bruch's membrane opening distance measurements and the cup/disc ratio (p = .007). Conclusion: Generally accepted belief is that lamina cribrosa visibility would be worse in healthy subjects who have thick prelaminar tissues, and better in individuals with glaucoma who had suffered the loss of prelaminar tissue. The difference between Bruch's membrane opening distance measurements taken with two devices was greater in normal eyes, and this difference was decreasing in glaucomatous eyes in our study. The Lamina Cribrosa measurement values shall not be directly compared between SD-OCT and SS-OCT.

Normative posterior pole asymmetry analysis data in healthy Caucasian population.

PURPOSE: The aim of this study is to evaluate the variability of central retinal thickness asymmetry in healthy Caucasian adults with the posterior pole asymmetry analysis to serve as a reference. METHODS: In total, 404 eyes of 202 subjects who aged between 18 and 80 years, who had no ocular pathology, were included in this cross-sectional observational study. Retinal thickness maps with posterior pole asymmetry analysis mode were taken with the optical coherence tomography (SPECTRALIS SD-OCT; Heidelberg Engineering). Superior and inferior hemifields were divided into five zones resembling to the strategy in Glaucoma Hemifield Test. Mean retinal thickness in each of the five zones was compared with the thickness of the corresponding zone in each eye (paired-samples t-test), and differences in retinal thickness (DRT1-5) and ganglion cell layer thickness between reciprocal locations were measured. Differences in retinal thickness values of two eyes of each subject were also compared (independent-samples t-test). RESULTS: The intra-eye asymmetry was statistically significant in zones 4 and 5. The highest mean intraocular differences in retinal thickness were 5.8 µm (zone 5) in all eyes, 5.8 µm (zone 5) in the right eyes, and 5.9 µm (zones 4 and 5) in the left eyes. The only statistically significant interocular local differences in retinal thickness asymmetries were found in zone 3. The intraocular asymmetry in retinal thickness was found to be the lowest in zone 1. The differences of ganglion cell layer thickness (GCLTs) were not statistically significant. CONCLUSION: There were statistically significant physiological inter-eye asymmetry in zone 3 and intra-eye asymmetries in zones 4 and 5. These measurements must be considered during screening for glaucoma with posterior pole asymmetry analysis in the Caucasian population.