Purpose To evaluate biomechanical corneal changes after pterygium excision surgery. Methods Prospective, interventional study in which 22 patients with unilateral pterygium were enrolled. Patients underwent pterigyum excision surgery with conjunctival autograft transplantation. The following corneal biomechanical properties were studied using Ocular Response Analyzer (ORA), preoperatively and postoperatively: Corneal Resistance Factor (CFR), Corneal Hysteresis (CH), Goldman correlated intraolcular pressure (IOPg) and Corneal Compensated IOP (IOPcc). Results CRF increased after pterygium excision surgery. Nevertheless, CRF returned to normal values at day 30. There was a decrease in CH parameters at day 7 and at day 30 compared with preoperative values. There was an increase in IOP, IOPg and IOPcc postoperatively. Conclusion CH decreases after pterygium surgery probably because of the elimination of a biomechanical reinforcement provided by the fibrovascular tissue that invades the anterior stroma. The postoperative decrease in CH could influence the IOP measure, which could be infraestimated using the Golman applanation technique. ORA postoperavtive exploration provides more precise IOP values.

Purpose To study the role of optical coherence tomography (OCT) as a progression marker in patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Methods We studied 36 eyes of 18 patients meeting criteria for AD (6 patients with mild AD, 7 patients with moderate AD and 5 patients with severe AD), and 21 eyes of 42 patients meeting criteria for MCI. In these two groups, we evaluated cognitive impairment through the Mini‐Mental State Examination (MMSE), the verbal fluency test (VFT) and the clock test (CT) and we measured peripapillary retinal nerve fiber layer (RNFL) thickness, and macular volume and thickness using OCT. Results There is a significant correlation between the decrease in peripapillary RNFL thickness, macular volume and macular thickness and the severity of the cognitive impairment measured by the three neuro‐psychological tests (p=0.00). Conclusion The reduction in peripapillary and macular thickness and macular volume is related to the severity of cognitive impairment. Thus, OCT can be used for the diagnosis of AD and MCI (especially in the diagnosis of early‐ stage AD), as well as to evaluate cognitive impairment progression.

Purpose To compare the choroidal thickness in the macular area in eyes with an idiopathic epiretinal membrane (ERM) with that of unaffected fellow eyes and eyes of healthy controls. Methods Enhanced depth imaging (EDI) was obtained by spectral‐domain optical coherence tomography (SD‐OCT) (Spectralis, Heidelberg‐Engineering,Germany) in 66 eyes of 50 patients (73.91 ± 11.1 years) with ERM and 96 eyes of 96 healthy controls (74.04 ± 8.5 years). Eyes were divided into 3 groups: 66 eyes in group A (affected eyes with ERM), 36 eyes in group B (unaffected fellow eyes), and 96 eyes in group C (right eyes of age‐matched controls). Choroidal thickness was measured from the posterior edge of the retinal pigment epithelium to the choroid‐scleral junction in the subfoveal area (SCT) and 1 mm away from the fovea in the nasal (NCT) and temporal (TCT) regions. Statistical analysis was conducted to compare mean choroidal thicknesses. Results In the ERM group the mean choroidal thicknesses were 241.1± 98.1 µm at the fovea (SCT), 225.7 ± 88.7 µm nasally (NCT), and 232.6 ± 85.6 µm temporally (TCT). In the unafected fellow eyes these measurements were 216.4 ± 72 µm, 213.3± 73.7 µm, and 214.8 ± 71 µm, respectively. Finally, the control group showed the following values: 234.9 ± 100.4 µm, 224.7± 96.4 µm, and 233.0 ± 95.5 µm, respectively. Choroidal thickness did not show any statistically significant differences among the three groups of eyes when age was counted as a confounding variable (p>0.05, ANOVA test). Conclusion No relationship between the presence of an ERM and changes in choroidal thickness was found. Epiretinal membrane is a disease caused by changes in the vitreous humor. Choroid does not seem to participate in the pathogenesis of this disorder.

Purpose To evaluate choroidal thickness during childhood using enhanced depth imaging (EDI) spectral‐domain optical coherence tomography (SD‐OCT), and its correlation with age, sex, axial length (AL) and refractive error (RE) Methods Cross‐sectional study in which 93 eyes of 93 healthy children were studied using a 25 A‐scans‐EDI SD‐OCT protocol. Choroidal thickness was segmented manually, and an ETDRS grid was applied to analyze choroidal thickness and volume in each of its nine sectors. Two observers independently studied 30 children to assess repeatability and reproducibility, using intraclass coefficient (ICC). Results We included 50 males and 43 females, with mean age of 9.62±2.89 years, mean refractive error (spherical equivalent) +0.03±2.22D and mean axial length (AL) of 23.19±13mm. Mean subfoveal choroidal thickness (SFCT) and volume was 314.22 ±55.48, and 0.25±0.04m3, respectively. SFCT was significantly thicker in the hyperopic group (AL 22.39±0.83mm). There were no statistically significant differences between myopic (AL 24.33±0.76mm) and emmetropic (AL 23.27±0.54mm) children, as well as between males and females. There was a weak, positive correlation between SFCT and age (r=0.259, p=0.012). Inter and intra‐observer ICC of the nine sector of the ETDRS grid ranged from 0.929‐0.991 and 0.992‐0.998, respectively. Conclusion Pediatric SFCT is greater in hyperopic children. The choroid appears to become thicker with age. Manual choroidal thickness segmentation by EDI SD‐OCT showed a high inter and intra‐observer repeatability

Purpose Present study compared the choroidal thickness in patients with diabetic macular edema (DME) with that in healthy controls to know the true role of choroids in DME. Methods Twelve eyes of 9 patients with DME (65.5±8.4 years), 9 contralateral eyes without DME (60.2±13.7 years), and 186 eyes of 96 age‐matched healthy volunteers (62.1±19.4 years) underwent enhanced depth imaging (EDI) spectral‐domain optical coherence tomography with a Heidelberg Spectralis HRA+OCT. Results Reliable measurements of choroidal thickness were obtained in 72.3% of eyes examined. In the DME group the mean choroidal thicknesses were 232.4±74.7 µm at the fovea, 223.3±70.0 µm nasally, and 234.0±72.9 µm temporally. In the contralateral eyes these measurements were 279.9±103.6 µm, 252.8±86.4 µm, and 283.9±101.4 µm, respectively. Finally, the control group showed slightly higher values: 288.6±114.5 µm, 279.1±112.7 µm, and 283.8±104.3 µm, respectively. However, choroidal thickness did not show any statistically significant differences among the three groups of eyes (p>0.05, ANOVA test). Conclusion Although a decreased choroidal thickness has been reported in eyes with DME, no differences were found in present study when age was counted as a confounding variable. Age has a strong inverse relationship with choroidal thickness.