Systemic oxidative stress biomarkers in patients with vitreomacular traction syndrome.

PURPOSE: To evaluate whether the systemic oxidative stress biomarkers increased in patients with vitreomacular traction syndrome (VMT). METHODS: This study compared 25 patients diagnosed with VMT with 20 healthy controls. As a biomarker of systemic oxidative stress, malondialdehyde (MDA) was measured. Total oxidant status (TOS) and total antioxidant status (TAS) were measured to evaluate the systemic oxidant status. RESULTS: Serum MDA values were significantly higher among the patients (p < 0.001). The ideal cut-off value for MDA was determined to be 22.1 µmol/L, with 80% sensitivity and 75% specificity. The between-group differences were not statistically significant for TOS or TAS (p = 0.326 and p = 0.698, respectively). CONCLUSION: Increased MDA levels suggest that systemic oxidative stress may play a role in VMT.

COMPARISON OF INTRAVITREAL DEXAMETHASONE IMPLANT AND AFLIBERCEPT IN PATIENTS WITH TREATMENT-NAIVE DIABETIC MACULAR EDEMA WITH SEROUS RETINAL DETACHMENT.

PURPOSE: To compare the efficacy and safety of intravitreal dexamethasone (DEX) implant versus aflibercept in patients with treatment-naive diabetic macular edema with inflammatory biomarkers. METHODS: Ninety-eight eyes of 62 treatment-naive patients with diabetic macular edema with serous retinal detachment and hyperreflective foci were enrolled. Each patient was randomized to receive either aflibercept or DEX implant treatment. The treatment protocol included 3 monthly injections of 2 mg of aflibercept as a loading phase in the anti-vascular endothelial growth factor group and 0.7 mg of DEX implant in the DEX group and then pro re nata treatment. Primary outcome measures were mean changes in visual acuity and central retinal thickness at the end of the 12-month follow-up. RESULTS: Forty-eight eyes of 29 patients were received DEX implant, and 50 eyes of 33 patients received the aflibercept injection. Mean central retinal thickness decreased from 615.2 µm at baseline to 297.7 µm at 12 months in the DEX group (P < 0.001) and from 576.5 µm to 367.4 µm in the aflibercept group (P < 0.001). Except for the first month, mean central retinal thickness reduction was significantly higher in the DEX group (P < 0.05, Mann-Whitney U Test). Visual acuity improved significantly at the end of the follow-ups (46.3-52.7 Early Treatment Diabetic Retinopathy Study letters in the DEX group and 47.5-56.8 Early Treatment Diabetic Retinopathy Study letters in the aflibercept group at 12 months, P < 0.001, paired-sample t-test). Adjusting by baseline values, the increase in mean visual acuity during the 12-month follow-ups favored the aflibercept group (P < 0.01), 25% of the DEX-treated eyes and 42% of the aflibercept treated eyes experienced 10 or more Early Treatment Diabetic Retinopathy Study letters visual gain (P: 0.058). The DEX group received significantly fewer (2.6 vs. 7.2) injections (P: 0.001). CONCLUSION: It was observed that the both of DEX implant and aflibercept were effective and safe in treatment-naive diabetic macular edema patients with inflammatory phenotype. Anatomical results were found to be better in the DEX group, and functional results were found to be better in the aflibercept group. In pseudophakic eyes, the functional superiority of aflibercept ceased to exist, and the low number of injections in the DEX implant group was seen as an advantage.

THE EFFECT OF AGE ON AFLIBERCEPT (EYLEA) RESPONSE IN DIABETIC MACULAR EDEMA.

PURPOSE: To investigate the effect of age on aflibercept (Eylea) response in macular edema secondary to treatment-naive diabetic eyes. METHODS: Two hundred seventy-three eyes of 273 treatment-naive patients with macular edema secondary to diabetes mellitus were enrolled in this study. The patients in the study were divided into the following 4 groups according to their ages: Group 1 (40-50 years), Group 2 (51-60 years), Group 3 (61-70 years), and Group 4 (>70 years). Three consecutive injections at intervals of 1 month were applied to all diabetic patients. The efficacy of the aflibercept treatment on macular edema according to age groups was assessed by optical coherence tomography by comparing the central foveal thickness (CFT) values and mean visual acuity changes after initial and three loading dose injections. RESULTS: After three consecutive aflibercept injections, the mean reduction of CFT in Groups 1, 2, 3, and 4 were -256.4 ± 110.9, -197.4 ± 96.4, -189.4 ± 110.8, and -186.2 ± 118.9 µm, respectively. The changes of CFT was significantly different between age groups (P = 0.003, analysis of covariance). The improvement of visual acuity was significantly different in each group (P < 0.001 in all groups, paired-samples t-test), and changes of visual acuity was significantly different between age groups (P < 0.05, analysis of covariance). In addition, ages of patients were correlated with the mean reduction of CFT and mean improvement of visual acuity for the whole study group (r = -0.183, P = 0.002 for CFT; r = -0.682, P < 0.001 for visual acuity, Pearson correlation). CONCLUSION: In this study, it was observed that the efficacy of aflibercept treatment was found to be more effective in younger patients in treatment-naive diabetic macular edema patients.

Comparison of the balafilcon A and samfilcon A lenses on postoperative pain control and epithelial healing time after photorefractive keratectomy: a contralateral eye study.

To compare the effects of balafilcon A and samfilcon A silicone hydrogel bandage contact lenses on postoperative pain control and epithelial healing time after photorefractive keratectomy (PRK). Seventy-four eyes of 37 patients who underwent bilateral PRK were included in this randomized clinical trial study. In the end of the surgery, a balafilcon A lens was used in one eye and a samfilcon A lens was used in the fellow eye randomly. Pain, blurred vision, epiphora, photophobia, and foreign body sensation were assessed on the first and third postoperative day using a visual analogue scale (0 = no ocular pain or discomfort, 10 = highest level of ocular pain and discomfort). For balafilcon A and samfilcon A lenses, mean scores for pain were 6.22 ± 2.81 and 3.11 ± 2.90 on first postoperative day (p < 0.001) and 1.57 ± 1.65 and 0.68 ± 0.85 on third postoperative day (p = 0.001), respectively; mean scores for foreign body sensation were 6.11 ± 2.53 and 3.19 ± 2.72 on first postoperative day (p < 0.001) and 3.16 ± 1.92 and 1.35 ± 1.43 on third postoperative day (p < 0.001), also respectively; and mean scores for epiphora were 6.46 ± 2.64 and 5.46 ± 3.40 on first postoperative day (p = 0.007) and 1.68 ± 1.60 and 1.32 ± 1.31 on third postoperative day (p = 0.065), again respectively. No significant difference in blurred vision or photophobia emerged between the lenses on first and third postoperative day after PRK. On the third postoperative day, reepithelialization was complete in 83.7% of eyes with the balafilcon A lens and 89.1% of eyes fitted with the samfilcon A lens. Wearing samfilcon A lenses after photorefractive keratectomy can significantly manage pain, decrease foreign body sensation on first and third postoperative day, and reduce epiphora on first postoperative day.

Evaluation of retina nerve fiber layer, ganglion cell-inner plexiform layer and lamina cribrosa in clinically unilateral exfoliative glaucoma.

PURPOSE: To compare retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GC-IPL), the lamina cribrosa depth (LCD) and thickness (LCT) in unilateral exfoliative glaucoma (EXG) patients with their fellow eyes without exfoliation and control eyes. METHODS: This cross-sectional prospective single-center study consisted of 64 eyes of 32 patients with unilateral EXG and 35 eyes of controls. All subjects were examined with spectral domain optical coherence tomography for the RNFL and GC-IPL measurements. The LCD and LCT measurements were also obtained. RESULTS: The RNFL measurements at all quadrants were statistically thinner in EXG eyes than those in their eyes without EXG and control eyes (p < 0.001 for average, superior, temporal and inferior; p = 0.004 for nasal). The EXG group had deeper LCD than their eyes without EXG and control eyes (p < 0.001, for both). The fellow eyes of EXG group had also deeper LCD than control eyes, with no statistical significance (p = 0.058). The mean LCT was thinner in EXG eyes compared to those in the eyes without EXG and control eyes (p < 0.001, for both). The eyes without EXG and control eyes had similar LCT (p = 0.293). CONCLUSIONS: Recent developments in imaging technology give the clinician detailed structural information about optic nerve head and retina such as GC-IPL, LCD and LCT. In addition to follow-up of RNFL changes, these new parameters may be useful in recognizing progression in EXG patients.

Diurnal variation of anterior segment parameters handled with Scheimpflug imaging in keratoconus patients.

PURPOSE: To define diurnal changes in anterior segment parameters of keratoconus patients by using Scheimpflug imaging. METHODS: All keratoconus patients had corneal topography measurements 3 times a day (around 09:00 AM, 13:00 PM and 17:00 PM) by the same experienced operator. Three consecutive scans in each measurement session were obtained. The average of three measurements was used for analysis. A repeated measures analysis of variance with one within-subject factor (time of day) was carried out to assess diurnal variation. RESULTS: This study included 26 eyes of 26 patients with keratoconus. Significant diurnal variation was found in CCT and TCT measurements (P < 0.01, and P < 0.01, respectively). The mean amplitudes of change in CCT and TCT were 4.2 ± 1 µm (95% CI: 1.7-6.8 µm) and 4.1 ± 1.1 µm (95% CI: 1.2-8.0 µm), while the mean of CCT and TCT were 462.4 ± 34.5 µm (95% CI: 448.4-476.6 µm) and 452.9 ± 6.6 µm (95% CI: 439.3-466.5 µm), respectively. The maximum value and the lowest value were observed at 09:00 AM and at 17:00 PM, respectively. Other parameters except CCT and TCT did not show diurnal variation. CONCLUSION: Statistically significant but clinically insignificant diurnal variation in CCT and TCT measurements of the keratoconus patients were detected over an 8-hour period (09:00 AM-17:00 PM).

Does using topical latanoprost affect subfoveal choroidal thickness?

Purpose: The aim of our prospective study was to investigate the effect of using latanoprost eye drops on subfoveal choroidal thickness in the macular area, as measured by using enhanced depth imaging optical coherence tomography (EDI-OCT). Materials and methods: A total of 39 eyes from 39 patients with bilateral glaucoma or ocular hypertension who had never received hypotensive therapy (study group) and 39 eyes from 39 age- and gender-matched healthy individuals (control group) were included in this study. The EDI-OCT measurements of subfoveal choroidal thickness were obtained during an initial visit before latanoprost therapy and at visits after 1 and 3 months of latanoprost therapy. Results: The mean subfoveal choroidal thickness was 309.5 ± 38.5 µm before latanoprost therapy in the study group and 307.3 ± 31.8 µm in the control group (p = .794). During latanorprost therapy in the study group, mean values of subfoveal choroidal thickness at the initial visit and at intervals of 1 and 3 months were 309.5 ± 38.5 µm, 314.2 ± 39.7 µm, and 318.3 ± 33.4 µm, respectively, which indicated a statistically significant difference between the initial and third visits only (p=.002). Conclusion: Subfoveal choroidal thickness increased after 3 months of topical latanoprost therapy.

An assessment of ocular elasticity using real time ultrasound and ocular response analyzer in active or remission rheumatoid arthritis.

PURPOSE: To investigate the elasticity of ocular structures in patients with rheumatoid arthritis (RA) without ocular involvement. METHODS: The study included 56 RA patients (study group) and 24 healthy volunteers as the control group. The rheumatoid arthritis patients were divided into two subgroups as those in active phase (Group 1, n = 25) or in remission phase (Group 2, n = 31) according to the disease activity index (DAS 28) score. The elastography values of the ratio of orbital fat-sclera (ROF/S) were measured with real-time US elastography, and corneal mechanical values were measured with the Reichert Ocular Response Analyzer in each eye. RESULTS: The mean ROF/S value was 5.2 ± 1.8 in Group 1, 0.7 ± 0.4 Group 2, and 0.6 ± 0.1 in the control group. There was a significant difference between the Group 1 and control group with regard to ROF/S (p < 0.001), but no significant difference was determined between Group 2 and control group (p > 0.05). The mean ROF/S value was a significant difference between the Group 1 and 2 (p < 0.001). ROF/S was significantly correlated with DAS-28 and C-reactive protein (CRP) (r = 0.816, p < 0.001 and r = 0.259, p = 0.006). CONCLUSIONS: ROF/S was significantly increased in patients in the active phase of RA. Findings revealed that ocular tissue structural changes may occur in the active phase and these could be related to ocular complications as a prognostic factor.

Corneal Sublayers Thickness in Patients With Mitral Valve Prolapse.

OBJECTIVES: The aim of this study was to compare the thickness of each corneal sublayer in patients with mitral valve prolapse (MVP) and healthy individuals. METHODS: A total of 38 eyes from 38 patients with MVP and 34 eyes from 34 age- and sex-matched healthy individuals were included in this study. The thickness of the corneal epithelium, Bowman layer, stroma, and Descemet membrane-endothelium complex were measured on the central cornea (i.e., corneal apex) and both the inferior and superior halves of the cornea with anterior segment module of spectral domain optical coherence tomography. RESULTS: No statistically significant differences emerged between the study and control groups in terms of Bowman layer thickness in the central cornea and the cornea's superior half (P=0.092 and P=0.128, respectively). However, in the inferior half of the cornea, Bowman layer thickness among patients with MVP was 11.95±2.34 µm (range 7-16 µm) and in the control group was 13.03±1.62 µm (range 10-16 µm), which made for a statistically significant difference (P=0.025). CONCLUSIONS: Our study revealed thinning of Bowman layer in the inferior half of the cornea in patients with MVP.

Assessing posterior ocular structures in ß-thalassemia minor.

PURPOSE: The aim of this study was to investigate the effect of ß-thalassemia minor on choroidal, macular, and peripapillary retinal nerve fiber layer thickness. METHODS: To form the sample, we recruited 40 patients with ß-thalassemia minor and 44 healthy participants. We used spectral-domain optical coherence tomography to take all measurements of ocular thickness, as well as measured intraocular pressure, axial length, and central corneal thickness. We later analyzed correlations of hemoglobin levels with ocular parameters. RESULTS: A statistically significant difference emerged between patients with ß-thalassemia minor and the healthy controls in terms of mean values of subfoveal, nasal, and temporal choroidal thickness (p = 0.001, p = 0.016, and p = 0.010, respectively). Except for central macular thickness, differences in paracentral macular thicknesses between the groups were also significant (superior: p < 0.001, inferior: p = 0.007, temporal: p = 0.001, and nasal: p = 0.005). Also, no statistically significant differences were noted for retinal nerve fiber layer thickness between two groups. CONCLUSION: Mean values of subfoveal, nasal, temporal choroidal, and macular thickness for the four quadrants were significantly lower in patients with ß-thalassemia minor than in healthy controls.

Impact of dehydration and fasting on intraocular pressure and corneal biomechanics measured by the Ocular Response Analyzer.

PURPOSE: To investigate the effects of dehydration and fasting on the intraocular pressure (IOP) and corneal biomechanics during Ramadan in healthy subjects. METHODS: A total of 36 healthy fasting male volunteers with a mean age of 32.7 ± 5.1 years (range 28-38 years) were enrolled in the study. A Reichert Ocular Response Analyzer (ORA) was used to measure the corneal resistance factor (CRF), corneal hysteresis (CH), Goldman-correlated IOP (IOPg), and corneal-compensated IOP (IOPcc), additionally IOP with Goldmann applanation tonometer (IOP-GAT) was taken. All measurements were recorded at 8:00 am and 4:00 p.m. during Ramadan and during a 1-month follow-up after Ramadan was over. RESULTS: Statistical analysis demonstrated no difference in the ORA measurements including CH, CRF, IOPcc, and IOPg; CCT and CV values between fasting and non-fasting periods or within a single day (diurnal changes). Nine volunteers (25% of total subjects) were excluded because eyedrops were believed to disrupt the Ramadan fast consequently IOP-GAT could not be measured from these subjects. No statistically significant difference was noted between IOP-GAT and IOPg measurements of twenty-seven subjects at the different periods and time points. CONCLUSIONS: Our results reveal that fasting during Ramadan does not profoundly affect corneal biomechanics and IOP values in healthy volunteers without ocular diseases such as glaucoma. When planning corneal refractive surgery and determining IOP, the ORA measurements can be done safely during a Ramadan fast. Moreover, ORA may be a better alternative for patients that refuse IOP measurement via GAT for examining the accuracy of IOP during fasting. Further studies are needed to better understand the role of these parameters on corneal disease and glaucoma during fasting.

Does Valsalva Maneuver Affect Corneal Morphology in Eyes With Keratoconus?

OBJECTIVES: The aim of this study was to investigate the effect of the Valsalva maneuver on corneal morphology and anterior chamber parameters in patients with keratoconus. METHODS: A total of 39 eyes from 39 patients with keratoconus and 41 eyes from 41 age-matched and gender-matched healthy individuals were included in this cross-sectional study. Measurements of corneal front keratometry values (K-flat, K-steep, and K-max), central corneal thickness, corneal apex thickness, thinnest corneal thickness, corneal volume, anterior chamber volume (ACV), anterior chamber depth (ACD), and iridocorneal angle (ICA) were performed with a Pentacam Scheimpflug camera (Oculus, Germany) before and during the Valsalva maneuver. Changes in the anterior segment parameters from baseline and during the Valsalva maneuver and the differences in parameters between the keratoconus group and the control group were analyzed. A P value less than 0.05 was accepted as statistically significant. RESULTS: In the patients with keratoconus, the Valsalva maneuver did not have any significant influence on the corneal parameters (P>0.05). However, ACV, ACD, and ICA decreased markedly during the Valsalva maneuver (P=0.006, P=0.048, and P=0.025, respectively). Changes caused by the Valsalva maneuver were similar for all parameters when compared with those in healthy individuals (P>0.05). CONCLUSIONS: During corneal topography imaging, the Valsalva maneuver observed in patients with keratoconus does not typically cause any significant change in corneal morphology.

Evaluation of foveal photoreceptor layer in eyes with macular edema associated with branch retinal vein occlusion after ozurdex treatment.

The aim of this study was to evaluate the central retinal thickness (CRT), outer nuclear layer thickness (ONLT), photoreceptor layer thickness (PLT), photoreceptor layer integrity, and the correlation between visual acuity and PLT in eyes with branch retinal vein occlusion (BRVO) 2 months after treatment with intravitreal dexamethasone implant (Ozurdex; Allergan, Inc, Irvine, CA). In this prospective study, 32 eyes of 32 patients were enrolled. A single injection of Ozurdex was administered to all the patients. CRT, ONLT, and PLT were measured using spectral-domain optical coherence tomography before and 2 months after the injection. Best-corrected visual acuity (BCVA [logMAR]) and photoreceptor cell integrity were also evaluated. The average CRT, ONLT, PLT, and BCVA values for the sample group before the treatment were as follows: 707 ± 261, 608 ± 288, 70 ± 25, and 0.96 ± 0.22 µm, respectively. The average CRT, ONLT, PLT, and BCVA values for the sample group 2 months after the Ozurdex injection were as follows: 299 ± 149, 211 ± 138, 77 ± 20, and 0.63 ± 0.30 µm, respectively (p < 0.05). Two months after the Ozurdex injection, BCVA correlated with ONLT and PLT (r = 0.365, p = 0.048 and r = -0.488, p = 0.021, respectively), whereas BCVA was not correlated with CRT (r = 0.239, p = 0.189). Photoreceptor layer is associated with the visual function of eyes with macular edema secondary to BRVO. Also, ONLT seems to be more closely related to visual acuity improvement than CRT decrement.

The assessment of choroidal thickness with spectral-domain optical coherence tomography during Valsalva maneuver.

PURPOSE: The purpose of the study was to evaluate the effect of Valsalva maneuver (VM) on choroidal thickness. METHODS: All the volunteers underwent a detailed opthalmic examination. Third-generation Spectralis OCT device (software version 5.6.3.0; Spectralis OCT, Heidelberg Engineering, Dossenheim, Germany) was used for assessment. Subfoveal and perifoveal CT of all volunteers were measured by using EDI-OCT technology. Perifoveal CT was measured 1500 µm nasally and 1500 µm temporally apart from the foveal center. The measurements were repeated while volunteers were performing VM. RESULTS: Sixty-four eyes of 32 healthy volunteers were assessed. The volunteers were aged 29-50. The mean age was 32.8 ± 6.6 years. Choroidal thickness measurements differed with statistical significance between resting position and VMin all regions (p < 0.001). While mean subfoveal CT was 350.64 ± 87.73 µm during resting position, it was 369.95 ± 90.12 µm during VM (p < 0.001). While mean nasal CT was 292.14 ± 81.67 µm during resting position, it was 305.46 ± 85.80 µm during VM (p < 0.001). While mean temporal CT was 325.93 ± 80.91 µm during resting position, it was 343.21 ± 81.53 µm during VM (p < 0.001). CONCLUSIONS: We found statistically significant increase in choroidal thickness during the VM in healthy volunteers. This result might be important for future studies researching autoregulation of choroidal and retinal blood flow in physiologic and pathologic conditions. Also, our study is noteworthy to stand out the errors in EDI-OCT measurements caused by unintentional breath holding of patients.

Evaluation of central corneal and central retinal thicknesses and intraocular pressure in acromegaly patients.

INTRODUCTION: Acromegaly is a disorder with increased morbidity which can involve many organs and the eye can be one of them which was investigated in few reports. Herein, we aimed to evaluate CCT, IOP and retinal thickness (RT), and their relationships with serum GH and IGF-1 levels and disease duration, in acromegaly patients. We compared the ocular parameters with those of a control group. This study included the largest number of patients of any comparable investigation to date. MATERIAL AND METHOD: We enrolled 30 acromegaly patients (15 male, 15 female and age: 48.4 ± 12.8 years) and 21 age and gender matched controls. All participants underwent complete hormonal and ophtalmological evaluation including central corneal thickness (CCT), retinal thickness (RT) and intraocular pressure (IOP) values. RESULTS: There were no significant differences in median right and left CCTs and mean CCT (p = 0.646, p = 0.667 and p = 0.384, respectively). Nor were there statistically significant differences in median right and left RT, or mean central RT, between the acromegaly and control groups (p = 0.977, p = 0.738 and p = 0.811, respectively). However median right, left and mean IOPs were found to be significantly higher in the acromegaly group, despite there being no difference in the CCT values (p = 0.011, p = 0.028 and p = 0.047, respectively). When we analyzed two subgroups of acromegaly patients (active/inactive), we found that the median right, left and mean CCTs and RTs, were not significantly different between the groups. Although there was a significant difference in IOP between the acromegaly and control groups, the two subgroups of acromegaly patients had similar IOPs (p = 0.400, p = 0.621 and p = 0.451 for right, left and mean IOPs, respectively). IOP was not found to be correlated with serum IGF-I, GH or disease duration in acromegaly patients. CONCLUSION: Our study results suggest that acromegaly is associated with increased ocular pressures irrespective of disease activity. Therefore detailed ocular evaluation should be a routine component of the follow up visits of acromegaly patients.

The safety and efficacy of phacoemulsification surgery in uncomplicated cataracts with and without an ophthalmic-viscosurgical-device.

PURPOSE: To compare and evaluate the results of phacoemulsification surgery involving and not involving an ophthalmic-viscosurgical-device (OVD). METHODS: A prospective, randomized controlled trial included 60 eyes of 60 patients scheduled to receive phacoemulsification surgery. In order of presentation, patients were randomized into two groups to undergo different surgical techniques: the OVD-free group (n = 30) and the OVD group (n = 30). Each patient's operating time, total ultrasonography (U/S) time, cumulative dissipated energy (CDE), aspiration time, and volume of balanced salt solution (BSS) aspirated were recorded. At 1 day, 1 week, and 1 and 3 months postoperation, measurements of endothelial cell density (ECD) and intraocular pressure (IOP), were taken and compared between the groups. RESULTS: Total U/S time (p = .567) and CDE (p = .168) were similar between the groups. In the OVD group, operating time (p = .011), aspiration time (p < .001), and volume of BSS aspirated (p < .001) were greater than in the OVD-free group. The change in ECD between the groups was not statistically significant at all visits (p = .433, p = .147, p = .379, p = .534; respectively). Although IOP increased in the OVD group at 1 day postoperation (p = .001), no difference emerged between the groups at 3 months postoperation (p = .121). CONCLUSION: Phacoemulsification surgery without an OVD took less time than with the OVD and caused no significant loss in ECD. Surgeons concerned about elevated IOP following cataract surgery should apply the OVD-free method.

Evaluation of the change in retinal thickness after femtosecond laser-assisted laser in situ keratomileusis and photorefractive keratectomy.

PURPOSE OF THE STUDY: To investigate the change in individual retinal layer thickness by spectral-domain optical coherence tomography (SD-OCT) in eyes underwent femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and photorefractive keratectomy (PRK). METHODS: In patients who underwent PRK and FS-LASIK, changes in the thickness of all retinal layers in the foveal, parafoveal, and perifoveal regions were evaluated by SD-OCT automated segmentation analysis at pre-operatively and different time points post-operatively. RESULTS: Seventy-one eyes of 71 patients (38 patients in PRK, 33 patients in LASIK) were included. In the pre-operative period, mean spherical equivalent (SE), mean keratometry, axial length, and segmentation values of the retinal layers were similar (P> .05). In the PRK group, the pre-operative measurements of individual retinal layers did not show a statistically significant difference compared to the post-operative measurements on the 1st day, 1st week, and 1st month. In the FS-LASIK group, the mean inner nuclear layer (INL) thickness one day after the surgery was significantly higher than that before surgery in the foveal (21.22 ± 4.66 µm vs 19.03 ± 4.50 µm, P= .013) and parafoveal regions (41.98 ± 3.70 µm vs 40.56 ± 3.49 µm, P= .044). CONCLUSIONS: The findings of our study suggest that the increase of INL thickness may be due to temporary structural and circulatory changes of the retina that may occur in the suction phase in the FS-LASIK procedure.

Effect of pupil dilation on intraocular pressure in preterm and term infants.

PURPOSE: To evaluate the effect of pupil dilation on intraocular pressure in preterm and term newborns. METHODS: This prospective study involved 55 eyes of 28 preterm infants and 38 eyes of 20 term infants. The infants were divided into two groups according to their gestational ages at birth as follows: preterm group, <37 weeks and term group, ≥37 weeks. Pupil dilation was attained with tropicamide 0.5% and phenylephrine 2.5%. Intraocular pressure measurements were performed with Icare PRO (Icare Finland Oy, Helsinki, Finland) before and after pupil dilation. A paired t test was used to compare the measurements before and after pupil dilation. RESULTS: The mean intraocular pressure change was -1.04 ± 3.03 mmHg (6.20/-11.40 mmHg) in the preterm group and -0.39 ± 2.81 mmHg (4.60/-9.70 mmHg) in the term group. A statistically significant difference in intraocular pressure was observed only in the preterm group after pupil dilation (p=0.01). CONCLUSION: An unexpected alteration in intraocular pressure in newborns may occur after pupil dilation, especially in preterm infants.