The Relationship between Visual-Evoked Potential and Optic Coherence Tomography and Clinical Findings in Parkinson Patients.

Background: In Parkinson's disease (PD), dopamine deficiency is present not only in the nigrostriatal pathway but also in the retinal and visual pathways. Optic coherence tomography (OCT) can be used as morphological evidence of visual influence from early nonmotor symptoms. The aim of this study was to investigate the relationship of OCT and visual evoked potentials (VEPs) of eyes with the severity of clinical findings and ocular findings in PD. Methods: A group of 42 patients diagnosed with idiopathic PD and a control group of 29 people between the ages of 45-85 were included in our study. VEP was recorded in the patient and control groups. OCT measurement was made with the Optovue spectral-domain device. Foveal thickness and macular volume were measured in the foveal region and in the parafoveal and perifoveal regions in the temporal, superior, nasal, and inferior quadrants. RNFL (retinal nerve fiber layer) was measured in temporal, superior, nasal, and inferior quadrants. Ganglion cell complex (GCC) was evaluated in the superior and inferior quadrants. Using the UPDRS clinical scale, the relationship between measurements and the differences between the control group and the patient group were evaluated. Results: Among the OCT values in our study, foveal, parafoveal, perifoveal thickness, macular volume, RNFL, and GCC measurements were performed for the right and left eyes, and no difference was found between the patient group and the control group. There was no difference in VEP amplitude and latency values between the patient and control groups. The relationships between UPDRS and modified Hoehn Yahr staging and OCT and VEP measurements in the patient revealed no correlation. Conclusions: Studies on whether OCT measurements can functionally be a marker or which segments are more valuable for disease progression in patients with PD are needed. Visual dysfunction in PD cannot be attributed only to retinal pathology; however, the retina may provide monitoring of the status of dopaminergic neurodegeneration and axonal loss in PD.

Is hypermetropia regressing in accommodative esotropia? / A hipermetropia regride na esotropia acomodativa?

ABSTRACT Purposes: To evaluate the relationship of changes in hypermetropia and ocular alignment in patients with accommodative esotropia. Methods: The medical records of consecutive patients diagnosed with refractive accommodative esotropia (esotropia eliminated or decreased to within 10 D with full hyperopic correction) were retrospectively reviewed. Cycloplegic refractions culled from medical records were converted into spherical equivalents. Presence of amblyopia, changes in refractive error and ocular alignment at admission and after the follow-up period were evaluated. Results: Seventy patients (mean age: 6.01 ± 5.41 years; female: 60.6%; mean follow-up: 5.8 ± 3 years) had corrected esotropia of 40 ± 20 prismatic diopters at admission. The average decrease per year in near and distance deviations with glasses was 1.71 ± 3.96 prismatic diopters/year and 1.09 ± 3.25 prismatic diopters/year, respectively. The total myopic shift of the right and left eyes was 1.08 ± 1.35 D and 1.20 ± 1.40 D, respectively. Myopic shift/year was 0.22 D/year and 0.26 D/year, respectively. The correlation between the rate of myopic shift and rate of change in corrected near deviation was weak. The correlation for the rate of myopic shift was not high for the right and left eyes (r=0.18; p=0.15). Conclusion: The amount of deviation and hypermetropia gradually decreased in accommodative esotropia during follow-up. On the other hand, it may be incorrect to assure patients that the amount of deviation will decrease in parallel with the refractive error.(AU)

RESUMO Objetivo: Avaliar a relação entre alterações na hipermetropia e o alinhamento ocular em pacientes com esotropia acomodativa. Métodos: Foram analisados retrospectivamente prontuários médicos de pacientes consecutivos diagnosticados com esotropia acomodativa refrativa (com esotropia eliminada ou reduzida a menos de 10 D com correção completa da hipermetropia). As medidas de refração em cicloplegia obtidas dos prontuários foram convertidas em equivalentes esféricos. Avaliaram-se ainda a presença de ambliopia, alterações do erro refrativo e o alinhamento ocular à admissão e depois do período de acompanhamento. Resultados: Setenta pacientes (média de idade=6,01 ± 5,41 anos, 60,6% do sexo feminino, acompanhamento médio de 5,8 ± 3 anos) apresentaram esotropia de 40 ± 20 dioptrias prismáticas (DP) para perto à admissão. A diminuição média anual no desvio para perto e para longe com o uso de óculos foi de 1,71 ± 3,96 DP/ano e 1,09 ± 3,25 DP/ano, respectivamente. Os desvios miópicos totais dos olhos direito e esquerdo foram de 1,08 ± 1,35 D e 1,20 ± 1,40 D, respectivamente. Os desvios miópicos anuais foram de 0,22 D/ano e 0,26 D/ano para os olhos direito e esquerdo, respectivamente. A correlação entre a taxa de desvio miópico e a taxa de alteração do desvio para perto corrigido foi fraca. A correlação da taxa de desvio miópico não foi alta para os olhos direito e esquerdo (r=0,18, p=0,15). Conclusão: A quantidade de desvio e a hipermetropia diminuem gradualmente na esotropia acomodativa durante o acompanhamento. Por outro lado, pode não ser apropriado garantir aos pacientes que o desvio diminuirá em paralelo ao erro refrativo.(AU)

Is hypermetropia regressing in accommodative esotropia?

PURPOSES: To evaluate the relationship of changes in hypermetropia and ocular alignment in patients with accommodative esotropia. METHODS: The medical records of consecutive patients diagnosed with refractive accommodative esotropia (esotropia eliminated or decreased to within 10 D with full hyperopic correction) were retrospectively reviewed. Cycloplegic refractions culled from medical records were converted into spherical equivalents. Presence of amblyopia, changes in refractive error and ocular alignment at admission and after the follow-up period were evaluated. RESULTS: Seventy patients (mean age: 6.01 ± 5.41 years; female: 60.6%; mean follow-up: 5.8 ± 3 years) had corrected esotropia of 40 ± 20 prismatic diopters at admission. The average decrease per year in near and distance deviations with glasses was 1.71 ± 3.96 prismatic diopters/year and 1.09 ± 3.25 prismatic diopters/year, respectively. The total myopic shift of the right and left eyes was 1.08 ± 1.35 D and 1.20 ± 1.40 D, respectively. Myopic shift/year was 0.22 D/year and 0.26 D/year, respectively. The correlation between the rate of myopic shift and rate of change in corrected near deviation was weak. The correlation for the rate of myopic shift was not high for the right and left eyes (r=0.18; p=0.15). CONCLUSION: The amount of deviation and hypermetropia gradually decreased in accommodative esotropia during follow-up. On the other hand, it may be incorrect to assure patients that the amount of deviation will decrease in parallel with the refractive error.

Evaluation of the correlation between quantitative measurement of the foveal avascular zone and retinal vessel density and outer retinal disruptions in diabetic patients

Background/aim: The aim of the current study was to evaluate the correlation between the integrity of the outer retinal layers on optical coherence tomography (OCT) and objective parameters of retinal microvascular perfusion on optical coherence tomography angiography (OCTA). Materials and methods: A total of 105 eyes of 54 diabetic patients were included in the study. Integrity of the outer retinal layers including the external limiting membrane (ELM), ellipsoid zone (EZ), and interdigitation zone (IZ) was assessed by spectral-domain optical coherence tomography. The foveal avascular zone (FAZ) area and vessel density (VD) measurements in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in all the Early Treatment Diabetic Retinopathy Study (ETDRS) sectors were evaluated by OCTA. Associations between the quantitative measurement of the FAZ and retinal VD measurements and outer retinal disruptions were evaluated. Results: The FAZ area was correlated with outer retinal layer disruption both in the superficial plexus (r = 0.244, 0.228, 0.212, P = 0.013, 0.02, 0.031 for the ELM, EZ, and IZ, respectively) and the deep capillary plexus (r = 0.298, 0.234, 0.197, P = 0.002, 0.019, 0.048 for the ELM, EZ, and IZ, respectively). A significant relationship was also found between the VD measurements in the SCP and DCP in ETDRS sectors and the outer retinal layers disruption. Conclusion: The results of the current study show a significant relationship between the quantitative OCTA parameters and the integrity of the outer retinal layers. This finding reveals a correlation between retinal capillary nonperfusion and outer retinal disruption in eyes with diabetic retinopathy.

Evaluation of Optic Nerve Head Biomechanical Properties in Pseudoexfoliation Glaucoma with Real-time Elastography.

PURPOSE: To investigate the biomechanical properties of the optic nerve head in patients with Pseudoexfoliation (PEX) glaucoma using Real-time Elastography (RTE) and to compare these results with those of Primary Open Angle Glaucoma (POAG) patients and healthy subjects. METHODS: Twenty eyes of 20 PEX glaucoma patients (PEX group), 20 eyes of 20 POAG patients (POAG group), and 20 eyes of 20 healthy subjects (control group) were enrolled in this prospective study. The strain Ratios of Orbital Fat to Optic Nerve head (ROFON) and lateral rectus muscle to optic nerve head (RLRON) were determined. Comparisons were performed using Chi-square, Kruskal Wallis, Mann-Whitney U, and One-way ANOVA tests. RESULTS: The strain ratios of orbital fat to optic nerve head were 2.34, 6.85 and 1.76 in PEX glaucoma, POAG, and control groups, respectively (p<0.001). The strain ratios of the lateral rectus muscle to the optic nerve head were 0.51, 0.82, and 0.55 in PEX glaucoma, POAG, and control groups, respectively (p=0.256). CONCLUSION: The strain ratios of orbital fat to optic nerve head were different in PEX glaucoma patients than in POAG and control groups. RTE can provide biomechanical assessment of the optic nerve head in a non-invasive, quick, easily accessible, and user-friendly manner.

Optic Nerve Head Elastometry in Both Eyes of Patients with Unilateral Non-arteritic Anterior Ischaemic Optic Neuropathy - May It Be a Novel Aspect of the Pathogenesis?

In this prospective study, the biomechanical properties of optic nerve head (ONH) and cornea in both eyes of patients with non-arteritic anterior ischaemic optic neuropathy and healthy control eyes were investigated. ONH elastometry was measured with real-time elastography, and corneal elastometry was measured with ocular response analyser. Elastometry of cornea and ONH was lower in both eyes of patients with unilateral non-arteritic ischaemic optic neuropathy than in healthy control eyes. The role of these biomechanical differences in the pathogenesis of non-arteritic ischaemic optic neuropathy should be investigated further.

Blood lead and cadmium in age related macular degeneration in a Turkish urban population.

PURPOSE: To evaluate the blood lead (Pb) and cadmium (Cd) levels in age related macular degeneration (AMD) in a turkish urban population. METHODS: Blood Pb and Cd levels of 31 AMD patients and 24 age and gender matched controls with no sign of AMD were measured using dual atomic absorption spectrophotometer system (AAS). History of hypertension, diabetes mellitus, cigarette smoking, myocardial infarction and stroke were obtained from all subjects. Degree of AMD was grade 4 according to the Age-Related Eye Disease Study grading system. Median blood Pb and Cd levels were compared by using Students' t-test. RESULTS: Demographic properties like smoking status, presence of diabetes mellitus or hypertension, cerebrovascular occlusion history, serum cholesterol and lipid levels were not significantly different between groups except history of ischemic heart disease (3.22% vs 25% in AMD and control groups respectively, p = .022). Overall in AMD group blood Pb level was 2.83 ±â€¯0.15 µg/l and it was 2.63 ±â€¯0.23 µg/l in control group (p = .36). The Cd level was 3.25 ±â€¯0.20 µg/l in AMD group and 3.11 ±â€¯0.25 µg/l in control group (p = .67). The mean Pb (2.38 ±â€¯0.88 µg/l vs 2.91 ±â€¯1.37 µg/l for AMD vs control, p = .61) and Cd levels (3.06 ±â€¯1.34 µg/l vs 3.35 ±â€¯1.26 µg/l for AMD vs control, p = .56) in current and previous smokers with AMD were not significantly different from those of the current and previous smokers in control group. CONCLUSION: Blood Pb and Cd levels which reflect short term exposure were not significantly different in AMD patients and the control group. The difference was not significant either after involvement of previous or current smoker subjects.

Binocular Summation and Control of Intermittent Exotropia.

BACKGROUND: Binocular summation (BiS), or improvement in binocular vision exceeding the better eye alone, is affected by strabismus. Being easily measured, BiS may be a useful indicator for subjective outcomes like stereopsis in strabismus. This study aims to investigate the relationship between BiS and measures of control of intermittent exotropia (IXT). METHODS: Patients with IXT were recruited before undergoing strabismus surgery and underwent tests of binocular and monocular high- and low-contrast visual acuity, stereopsis at distance and near, and Newcastle Control Score (NCS), a score developed by incorporating home control and clinic control criteria into a control rating scale. BiS was calculated using high-contrast Early Treatment of Diabetic Retinopathy Study (ETDRS) and Sloan low-contrast acuity charts (LCA) at 2.5% and 1.25% contrast as the difference between the binocular score and that of the better eye. The relationship between BiS and measures of IXT control (NCS and distance near stereoacuity disparity) was evaluated using a correlation analysis by Spearman correlation coefficients and the Kruskal-Wallis test. RESULTS: Thirty-four patients were included (mean [± standard deviation (SD)] age 19±16 years) having a mean (±SD) of 26±16Δ IXT at distance and 20±16Δ at near. Mean (±SD) BiS for ETDRS and Sloan LCA at 2.5% and 1.25% was 0.8±3.6, 1.9±6.0, and -2.3±7.2, respectively. The Spearman correlation coefficient of BiS and NCS was -0.53 (95% CI -0.85 to -0.25) for 2.5% LCA and -0.43 (95% CI -0.77 to -0.13) for 1.25% LCA. BiS at 2.5% LCA (P=0.006) and at 1.25% LCA (P=0.029) significantly differed between the groups based on NCS score groupings (1-3, 4-6, and 7-9), with patients who had better control scores having higher levels of BiS. BiS did not differ significantly between patients grouped according to the difference between stereoacuity measured at near versus distance. CONCLUSION: Significantly lower low-contrast BiS in patients with higher NCS may suggest that decreased BiS is associated with less control in IXT. This finding suggests that BiS may reflect control in IXT across a population of patients with IXT.

Real-Time Ultrasound Elastographic Features of Primary Open Angle Glaucoma.

OBJECTIVE: To investigate the significance of ultrasound elastography for evaluating the optic nerve in patients with primary open angle glaucoma (POAG). METHODS: This prospective, comparative case series included 40 eyes of 40 patients. Twenty eyes with POAG comprised the POAG group, and 20 eyes of 20 patients without glaucoma who admitted to general eye clinic for near vision glasses comprised the control group. All real-time sonographicelastographic examinations were performed by the same physician. The ratio of orbital fat to optic nerve head (ROFON) and lateral rectus to optic nerve head (RLRON) were determined. Statistical analyses were performed using Student t test, Kolmogorov-Smirnov test, and χ test. RESULTS: The mean ages of the patients in the study and the control groups were 65.10 ± 7.88 years (range, 48-80 years), and 69.15 ± 7.92 years (range, 55-89 years), respectively (P = 0.113). Mean ROFONs were 1.85 and 6.42 (P < 0.05), and mean RLRONs were 0.65 and 1.07 (P < 0.05) in the control and POAG groups, respectively. CONCLUSIONS: Real-time elastography showed increased ROFON and RLRON in POAG patients. This can help to understand optic nerve head biomechanics and clarify glaucoma damage in early glaucoma cases.

Can Corneal Biomechanical Properties Give Clues About Elasticity of Optic Nerve Scleral Component in Nonarteritic Anterior Ischemic Optic Neuropathy?

OBJECTIVE: To investigate corneal biomechanical properties among individuals with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) compared to healthy gender- and age-matched subjects. METHODS: The study subjects were separated into 2 groups: 66 eyes of 33 patients with unilateral NAION (study group) and 33 eyes of 33 healthy individuals (control group). Reichert ocular response analyzer (Reichert Ophthalmic Instruments) was used to assess corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure values. Also, central corneal thickness was measured using Scheimpflug camera combined with a Placido disc corneal topographer (Sirius; Costruzioni Strumenti Oftalmici). RESULTS: Mean CH and median CRF values were significantly lower in the affected eyes (8.8 ± 1.8 mm Hg, 9.4 mm Hg, respectively) and contralateral unaffected eyes (9.1 ± 1.6 mm Hg, 9.8 mm Hg, respectively) of NAION patients than those in the control group (9.9 ± 1.3 mm Hg, 10.4 mm Hg, respectively; all P < 0.017). Mean IOPcc was significantly higher in the affected eyes of NAION patients (19.2 ± 3.5 mm Hg) than in the eyes of control group (17.1 ± 3.6 mm Hg; P = 0.002). CONCLUSIONS: CH and CRF are significantly reduced in patients with NAION, possibly indirectly reflecting structural weakness in the lamina cribrosa.

Isolated schwannoma involving extraocular muscles.

BACKGROUND: Progressive strabismus initially considered idiopathic may be caused by isolated schwannomas of motor nerves to extraocular muscles, detectable only on careful imaging. This study reviewed clinical experience of a referral practice in identifying schwannomas on magnetic resonance imaging (MRI). METHODS: We reviewed 647 cases imaged for strabismus to identify presumed cranial nerve schwannomas, identified by gadodiamide-enhanced, high-resolution surface coil orbital MRI and thin-section cranial MRI. Clinical features and management were correlated with MRI. RESULTS: Schwannomas were identified as fusiform intraneural enlargements in 8 cases: 1 affecting the trochlear nerve; 2, the abducens nerve; and 5 the oculomotor nerve. Involved muscles were atrophic. Both abducens schwannomas, 1 superior oblique, and 1 oculomotor schwannoma were subarachnoid; 3 were intraorbital, and bilateral oculomotor lesions of 1 case extended from cavernous sinus to orbit. Associated strabismus progressed for 3-17 years. Abducens schwannoma caused esotropia; trochlear schwannoma caused hypertropia and cyclotropia. Intracranial oculomotor schwannoma caused mydriasis and exotropia. Intraorbital schwannoma caused exotropia with or without hypertropia. Since lesion diameters were 3-9 mm, 6 had been previously missed on routine MRI. CONCLUSIONS: Progressive, acquired strabismus may be caused by isolated cranial nerve schwannomas, representing about 1% of strabismus cases in this study, involving the oculomotor more than abducens nerve. Because most schwannomas are small and deep in the orbit, findings could be readily missed by routine imaging, leading to a possible diagnosis of idiopathic strabismus. Schwannomas should be suspected when extraocular muscles are atrophic, but the causative lesions themselves are identifiable only using targeted, high resolution MRI.

Is there any association between primary hyperparathyroidism and ocular changes, such as central corneal thickness, retinal thickness, and intraocular pressure?

Ocular changes are commonly encountered in various endocrine disorders. However, only a few studies have reported ocular changes in patients with primary hyperparathyroidism (PHPT). Here, we examined the central corneal thickness (CCT), retinal thickness (RT), and intraocular pressure (IOP), and their relationships with serum intact parathyroid hormone (iPTH), calcium (Ca), and phosphorus (P) levels in patients with PHPT. Thirty-seven eyes of 37 PHPT patients were compared with 43 eyes of 43 age- and sex-matched normal subjects. A detailed ophthalmologic examination, including CCT, RT, and IOP, was performed. CCT and IOP in PHPT patients were significantly higher than controls (p = 0.024 and p = 0.038, respectively). No statistically significant difference was detected in RT between the two groups (p = 0.730). iPTH levels were positively correlated with CCT and IOP (r = 0.304, p = 0.006 and r = 0.249, p = 0.026, respectively). No significant correlation was found between iPTH levels and RT (p > 0.05), and between serum Ca levels, and RT, CCT, and IOP (all, p > 0.05). While there was a negative correlation between serum P levels and CCT (r = -0.264, p = 0.018), no correlation was observed between serum P levels, and RT and IOP (both, p > 0.05). Using multiple regression analyses, iPTH, serum Ca, and serum P levels were found to have no significant associations with CCT, IOP, and RT (all, p > 0.05). There was no significant association between PHPT, and CCT, RT, and IOP. We postulate that the identification of ocular aspects of PHPT is significant, and further studies related to this condition are required.

Corneal biomechanics in steroid induced ocular hypertension.

AIM: This study aims to investigate the corneal biomechanical properties of steroid sensitive refractive surgery patients and to compare these with those patients that did not have steroid induced ocular hypertension after refractive surgery. MATERIAL AND METHODS: This retrospective study in a tertiary care center involved 48 eyes with steroid induced ocular hypertension (Group I) and 61 eyes of age and sex matched refractive patients who used topical steroids for the same duration as group I without developing ocular hypertension (group II). All patients had preoperative ophthalmological examination, pachymetry and postoperative corneal hysteresis (CH) and resistance factor (CRF) measurements by ocular response analyser. The preoperative CH and CRF measurements of the two groups were compared. RESULTS: The mean CH was statistically lower in group I (6.89±1.62) as compared to group II (7.80±1.30) (p=0.001). The CRF was higher in group I (7.68±2.26) as compared to group II (7.66±1.72) but the difference was not statistically significant (p=0.96). The preoperative spherical refractive error (r=0.43, p=0.00) and postoperative corneal thickness (r=0.58, p=0.001) were moderately correlated with CH. CONCLUSIONS: A statistically significant decrease in CH in subjects with steroid induced ocular hypertension is found. Previous studies have revealed an association of low CH with risk of glaucomatous damage of optic nerve. This may imply risk of optic disc damage in this ocular hypertension group if not recognized and treated properly. However the results should be confirmed with larger sample sizes.

Macula and retinal nerve fiber layer in migraine patients: analysis by spectral domain optic coherence tomography.

AIM: Investigating the retinal nerve fiber layer (RNFL), macular and ganglion cell complex thickness in eyes of migraine patients using optical coherence tomography. METHODS: The study was designed as an observational cross-sectional study. 50 patients with migraine (30 patients with aura and 20 patients without aura) and 50 healthy volunteers were included. Optical coherence tomography was performed with Optovue technology. The fast RNFL thickness (3.4) scan, MM5, and GCC acquisition protocols were used. RESULTS: There was no statistically significant difference in retinal thickness in any of the quadrants between the control group and the migraine patients (p > 0.05). The average RNFL thickness (110.50 vs 102.84 microns, p = 0.03) was significantly thinner in migrainers as compared to the control. The ANOVA did not reveal any significant difference between migrainers with aura, migrainers without aura, and the control group. The VAS (visual analogue scale) score of migraine patients was not statistically significantly correlated with any of the parameters, while the length of migraine history was negatively correlated with the average RNFL thickness (r = -0.32, p = 0.03). CONCLUSION: The average RNFL thickness in the migraine patients was found to be thinner than that in the control group. In addition, we found a negative weak correlation between length of migraine history and the average RNFL thickness, supporting the possible association between these pathologies.

The Effect of Corneal Epithelium on Corneal Curvature in Patients with Keratoconus.

OBJECTIVE: To investigate the effects of corneal epithelium on corneal curvature in patients with keratoconus. DESIGN: This is a prospective, nonrandomized study. PARTICIPANTS: Fifty-nine eyes of 47 patients diagnosed as keratoconus and for whom corneal collagen crosslinking (CXL) was recruited in this study. METHODS: This study is a single-center clinical trial. Pregnancy, lactation, connective tissue disease, corneal thickness below 350 µm, severe dry eyes, or scar of corneal surgery were exclusion criteria. Before and during CXL procedure after removing the corneal epithelium, maximum values of corneal apical curvature, simulated keratometry 1 (Sim-K1), simulated keratometry 2 (Sim-K2), temporal and inferior curvature values, all of which are 1.5 mm from the corneal center, were calculated. These values before and after removal of epithelium were compared statistically. RESULTS: Mean age of patients was 23.30 ± 5.5 (12-38) years. Twenty-eight (59%) were male while 19 (41%) were female. Mean values measured before and after removing the corneal epithelium were: apical curvature; 59.19 ± 7.2 (47.06-82.40) diopter (D) and 61.70 ± 8.8 (49.19-92.66) D (p = 0.001), SimK1; 47.57 ± 4.3 (39.14-64.57) D and 48.23 ± 4.3 (41.89-66.70) D (p = 0.001), SimK2; 52.04 ± 5.3 (43.56-69.34) D and 53.34 ± 5.6 (43.73-70.89) D (p = 0.001), inferior curvature; 53,85 ± 5.2 (43.47-76.56) D and 55.05 ± 5.8 (44.56-81.93) D (p = 0.002), temporal curvature 49.49 ± 5.1 (41.50-71.03) D and 51.53 ± 5.4 (41.58-73.34) D (p = 0.001), respectively. CONCLUSIONS: In keratoconus patients during CXL treatment, after removing the corneal epithelium, more steepness is detected in the curvature of the steeper area of the cornea. When evaluating patients with keratoconus, the masking effect of corneal epithelium on values of curvature should be taken into consideration.

Evaluation of serum fibrinogen, plasminogen, α2-anti-plasmin, and plasminogen activator inhibitor levels (PAI) and their correlation with presence of retinopathy in patients with type 1 DM.

BACKGROUND. Diabetic retinopathy (DR) is the leading cause of blindness in the world. Retinopathy can still progress despite optimal metabolic control. The aim of the study was to determine whether different degrees of DR (proliferative or nonproliferative) were associated with abnormally modulated hemostatic parameters in patients with T1DM. METHOD. 52 T1DM patients and 40 healthy controls were enrolled in the study. Patients were subdivided into three categories. Group I was defined as those without retinopathy, group II with NPRP, and group III with PRP. We compared these subgroups with each other and the control group (Group IV) according to the serum fibrinogen, plasminogen, alpha2-anti-plasmin ( α2-anti-plasmin), and PAI. RESULTS. We detected that PAI-1, serum fibrinogen, and plasminogen levels were similar between the diabetic and control groups (P = 0.209, P = 0.224, and P = 0.244, resp.), whereas α2-anti-plasmin was higher in Groups I, II, and III compared to the control group (P < 0.01, P < 0.05, and P < 0.001, resp.). There was a positive correlation between serum α2-anti-plasmin and HbA1c levels (r = 0,268, P = 0.031). CONCLUSION. To our knowledge there is scarce data in the literature about α2-anti-plasmin levels in type 1 diabetes. A positive correlation between α2-anti-plasmin with HbA1c suggests that fibrinolytic markers may improve with disease regulation and better glycemic control.

Impaired corneal biomechanical properties and the prevalence of keratoconus in mitral valve prolapse.

Objective. To investigate the biomechanical characteristics of the cornea in patients with mitral valve prolapse (MVP) and the prevalence of keratoconus (KC) in MVP. Materials and Methods. Fifty-two patients with MVP, 39 patients with KC, and 45 control individuals were recruited in this study. All the participants underwent ophthalmologic examination, corneal analysis with the Sirius system (CSO), and the corneal biomechanical evaluation with Reichert ocular response analyzer (ORA). Results. KC was found in six eyes of four patients (5.7%) and suspect KC in eight eyes of five patients (7.7%) in the MVP group. KC was found in one eye of one patient (1.1%) in the control group (P = 0.035). A significant difference occurred in the mean CH and CRF between the MVP and control groups (P = 0.006 and P = 0.009, resp.). All corneal biomechanical and topographical parameters except IOPcc were significantly different between the KC-MVP groups (P < 0.05). Conclusions. KC prevalence is higher than control individuals in MVP patients and the biomechanical properties of the cornea are altered in patients with MVP. These findings should be considered when the MVP patients are evaluated before refractive surgery.

Retinal endoilluminator toxicity of xenon and light-emitting diode (LED) light source: rabbit model.

OBJECTIVE: This study evaluates retinal toxicity due to endoillumination with the light-emitting diode (LED) light source in comparison to endoillumination with xenon light source. MATERIAL AND METHODS: Twenty-five eyes of 14 New Zealand pigmented rabbits were used in the study. The LED light (Omesis Medical Systems, Turkey) group was composed of 7 right eyes, while the other 7 right eyes constituted the xenon group (420 nm filter, 357mW/cm(2)) (Bright Star; DORC, Zuidland, Netherlands). Eleven untreated left eyes composed the control group. Twenty gauge pars plana incision 1.5 mm behind the limbus was performed in the right eyes. Twenty gauge bullet type fiberoptic endoilluminator was inserted into the eye from the incision without any pars plana vitrectomy. Fiberoptic endoilluminator was placed in such a way that it was directed toward visual streak of the rabbit retina with a 5 mm distance to retinal surface. Endoillumination was then applied for 20 min with a maximum light intensity for LED and xenon light. In left control eyes, no surgical procedure and no endoillumination were performed. One week after the endoillumination procedure, both eyes of the rabbits were enucleated following electroretinography. Sections stained with hematoxylin and eosin to evaluate morphologic changes. Retina tissues were assessed by active caspase-3 staining. RESULTS: There was no difference in the shape of the waveforms recorded in the eyes endoilluminated with LED light and xenon light sources compared to control eyes both before and after endoillumination application (p > 0.05). Microscopic evaluation of the retinas with hematoxylin and eosin staining demonstrated that all study groups have normal histologic properties similar to control group. No apoptosis positive cells were found within all sections in all groups. CONCLUSIONS: When the LED light source is used with maximum power and limited duration for endoillumination in rabbit eyes it does not produce phototoxic effects that may be detectable by electrophysiology and histology similar to xenon light.