Gökhan Pekel

Intracorneal inlay to correct presbyopia: Long-term results

PURPOSE: To evaluate the long‐term visual results of Acufocus ACI‐7000 (now Kamra) intracorneal inlay implantation in presbyopic phakic patients. SETTING: Beyoğlu Eye Training and Research Hospital, Istanbul, Turkey. DESIGN: Clinical trial. METHODS: This study comprised patients with emmetropic or post‐laser in situ keratomileusis (LASIK) presbyopia. Patients had an uncorrected near visual acuity (UNVA) of 20/40 or worse, correctable to 20/25 or better at distance. The inlay was implanted on the stromal bed after the LASIK flap was relifted or a flap created. The inlay was centered on the presurgical position of the first Purkinje reflex. The main outcome measures were distance and near vision and the complication rate. RESULTS: The study enrolled 39 patients aged 45 to 60 years. At the 4‐year follow‐up, all patients (N = 22) had 2 or more lines of improvement in UNVA with no significant loss in distance vision. The mean final UNVA was 20/20 (Jaeger [J1]); 96% of patients could read J3 or better. The uncorrected distance acuity was 20/40 or better in all eyes. Five patients had cataract progression, and 2 had a change in refractive status. No eye with an intracorneal inlay had intraoperative complications during cataract extraction. Four inlays were explanted during the study. There were no severe corneal complications that affected final vision. CONCLUSION: Intracorneal inlay implantation was an effective, safe, and reversible procedure for the long‐term surgical treatment of presbyopia. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

Ocular complications of diabetes mellitus

Diabetes mellitus (DM) is a important health problem that induces ernestful complications and it causes significant morbidity owing to specific microvascular complications such as, retinopathy, nephropathy and neuropathy, and macrovascular complications such as, ischaemic heart disease, and peripheral vasculopathy. It can affect children, young people and adults and is becoming more common. Ocular complications associated with DM are progressive and rapidly becoming the worlds most significant cause of morbidity and are preventable with early detection and timely treatment. This review provides an overview of five main ocular complications associated with DM, diabetic retinopathy and papillopathy, cataract, glaucoma, and ocular surface diseases.

Central corneal thickness, anterior chamber depth, and pupil diameter measurements using Visante OCT, Orbscan, and Pentacam.

PURPOSE To evaluate the agreement among three different optical methods in measuring anterior chamber depth (ACD), central corneal thickness (CCT), and pupil diameter. METHODS One hundred eyes of 50 healthy patients (25 men, 25 women) were enrolled in the study. Mean patient age was 25 years (range: 21 to 32 years). Exclusion criteria were history of any intraocular or corneal surgery, contact lens wear, corneal anomalies, and spherical refraction >5.00 diopters (D) or cylindrical refraction >2.00 D. All measurements were done by the same operator under mesopic light conditions and repeated using three different optical methods: Visante optical coherence tomography (OCT) (Carl Zeiss Meditec), Orbscan (Bausch & Lomb), and Pentacam (Oculus Optikgeräte GmbH). RESULTS Mean CCT as measured by Visante OCT, Orbscan, and Pentacam was 529+/-30.5 microm, 554+/-32.7 microm, and 552+/-29.3 microm, respectively. Mean ACD values were 2.94+/-0.34 mm, 2.84+/-0.33 mm, and 2.98+/-0.33 mm, respectively. Mean pupil diameter measurements were 4.87+/-1.09 mm, 4.0+/-0.67 mm, and 3.05+/-0.59 mm, respectively. The Visante OCT measured CCT thinner and Orbscan measured ACD shallower than the other two methods. All three methods measured pupil diameters significantly different. CONCLUSIONS This study found some statistically significant but clinically insignificant differences among the optical methods assessed. The differences are small and do not influence decisions for refractive surgery in clinical practice.

Effects of chronic smoking on central corneal thickness, endothelial cell, and dry eye parameters

Abstract Objective: To evaluate the effect of chronic cigarette smoking on dry eye parameters, endothelial cells, and corneal thickness. Design: Prospective cross-sectional case series. Methods: In this cross-sectional study, 49 eyes of 49 chronic smokers (smoker group) and 53 eyes of 53 age-matched, healthy non-smokers (non-smoker group) were enrolled. All participants underwent measurements of tear breakup time (TBUT), central corneal thickness (CCT) measurements with contact pachymeter and the Schirmer test with anesthesia. Corneal endothelial cells were evaluated by non-contact specular microscopy and photographed for analysis of cell density and hexagonality and the coefficient of variation in cell size. Results: The mean Schirmer score and TBUT value were significantly lower in the smoker group compared to the non-smoker group (p = 0.015) and p < 0.001, respectively). No statistically significant difference was found in the mean CCT, mean endothelial cell density, endothelial cell size, SD of size, and CV of size between smokers and non-smokers (p > 0.05). However, a lower percentage of endothelial hexagonal cells were observed in smokers than non-smokers (p < 0.001). Discussion and conclusion: Our results suggest that cigarette smoking seems to affect the Schirmer score, TBUT value, and hexagonal cells of the corneal endothelium.

Ocular pulse amplitude and retina nerve fiber layer thickness in migraine patients without aura

BackgroundTo evaluate the ocular pulse amplitude (OPA), the posterior pole asymmetry analysis (PPAA), the peripapillary retinal nerve fiber layer (RNFL) thickness, the ganglion cell layer (GCL) thickness, macular thickness and visual field testing in migraine patients without aura.MethodsIn this prospective, cross-sectional and comparative study 38 migraine patients and 44 age and sex matched controls were included. OPA was measured by dynamic contour tonometry (DCT), PPAA, RNFL, GCL and macular thickness were measured by Heidelberg Spectral Domain Optical Coherence Tomography (SD-OCT) and standard perimetry was performed using the Humphrey automated field analyzer.ResultsThe difference in OPA was not statistically significant between the two groups (p ≥ 0.05). In the PPAA there was no significant difference between two hemispheres in each eye (p ≥ 0.05). The RNFL thickness was significantly reduced in the temporal and nasal superior sectors in the migraine group (p ≤ 0.05). The GCL and macular thickness measurements were thinner in migraine patients but the difference between groups was not statistically significant (p ≥ 0.05). There was no correlation between RNFL, GCL, macular thickness measurements and OPA values. There was no significant difference in the mean deviation (MD) and pattern standard deviation (PSD) between the two groups (p ≥ 0.05).ConclusionsMigraine patients without aura have normal OPA values, no significant asymmetry of the posterior pole and decreased peripapillary RNFL thickness in the temporal and nasal superior sectors compared with controls. These findings suggest that there is sectorial RNFL thinning in migraine patients without aura and pulsative choroidal blood flow may not be affected during the chronic course of disease.

Effect of intracameral epinephrine use on macular thickness after uneventful phacoemulsification.

PURPOSE: To evaluate changes in central macular thickness using optical coherence tomography after uneventful cataract surgery combined with intracameral epinephrine use. SETTING: Beyoğlu Eye Training and Research Hospital, Istanbul, Turkey. METHODS: This prospective case series comprised eyes of consecutive patients who had uneventful phacoemulsification and in‐the‐bag intraocular lens (IOL) implantation between August 2005 and January 2006. The eyes were randomly assigned to 1 of 2 groups. In 1 group, 0.2 mL epinephrine (1:5000 solution) was injected just after the clear corneal incision was created. The other group (control) did not receive epinephrine. Optical coherence tomography was performed in all eyes preoperatively as well as postoperatively at 1 day, 1 week, and 1, 3, and 6 months. RESULTS: The epinephrine group comprised 73 eyes (73 patients) and the control group, 76 eyes (86 patients). In both groups, the increase in retinal thickness from preoperatively to 1, 3, and 6 months postoperatively was statistically significant (P<.05); the difference was not statistically significant at 1 day or 1 week in either group (P>.05). There were no statistically significant differences between the 2 groups in mean retinal thickness throughout the follow‐up (P>.05). Clinically significant macular edema occurred in 3 eyes in the epinephrine group and 3 eyes in the control group. CONCLUSION: Although epinephrine is a well‐known risk factor for central macular edema, intracameral injection of 0.2 mL epinephrine (1:5000) did not increase the risk for central macular edema in eyes with no risk factors that had uneventful phacoemulsification with IOL implantation. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Comparison of intrastromal corneal ring segment implantation only and in combination with collagen crosslinking for keratoconus.

Purpose To compare visual outcomes, corneal astigmatism, and keratometric readings in patients with progressive keratoconus undergoing intrastromal corneal ring implantation (ICRSI) only and in combination with ultraviolet A riboflavin mediated corneal collagen crosslinking (CXL). Methods In this retrospective comparative study, there were 2 groups of keratoconus patients. Group 1 consisted of only ICRSI patients. Group 2 consisted of combined ICRSI-CXL patients. Preoperative and postoperative uncorrected distance visual acuity (UCDVA) and best-corrected distance visual acuity (BCDVA), spherical error, cylindrical error, and mean keratometry were compared. Results The study evaluated 166 eyes of 121 patients with a mean age of 24.74 years. The UCDVA improved from 0.24 to 0.37 in group 1 and from 0.24 to 0.42 in group 2 at the last visit. The BCDVA improved from 0.34 to 0.62 in group 1 and from 0.31 to 0.67 in group 2. Spherical error decreased from −5.05 D to −1.65 D in group 1 and from −4.82 D to −1.52 D in group 2. Cylindrical error decreased from −6.06 D to −3.47 D in group 1 and from −5.66 D to −3.20 D in group 2. Mean keratometry values decreased from 51.89 D to 47.96 D in group 1 and from 50.89 D to 46.91 D in group 2. p Value was ≥0.05 in group comparisons. Ring explantation due to corneal melting was applied in 3 eyes. Conclusions Both combined ICRSI-CXL and ICRSI-only groups experienced favorable outcomes, without statistical difference in any studied effect of both treatment strategies.

Comparison of Corneal Layers and Anterior Sclera in Emmetropic and Myopic Eyes.

Purpose: The aim of this study was to compare the thickness of preocular tear film, corneal layers, and anterior sclera in patients with moderate to high myopia and emmetropia with anterior segment spectral domain optical coherence tomography. Methods: This cross-sectional comparative study included 31 patients with high myopia and 31 emmetropic healthy controls. Patients with myopia had axial lengths ranging from 24 to 29 mm, whereas age-matched controls had axial lengths from 21 to 23.9 mm. Patients with myopia had refractive errors from −4.00 to −11.00 diopters spherical equivalent. Preocular tear film, corneal epithelium, Bowman layer, stroma, and Descemet membrane–endothelium complex were measured in the central cornea. Anterior scleral measurements were made at distances of 1, 3, and 5 mm from the limbus. Corneal–scleral thickness was measured with the anterior segment module of spectral domain optical coherence tomography. Results: No statistically significant differences (P > 0.05) between patients with myopia and controls emerged regarding the thickness of preocular tear film, corneal epithelium, Bowman layer, corneal stroma, and Descemet membrane–endothelium complex. The anterior scleral thickness values of 1, 3, and 5 mm from the limbus were similar in both patients with myopia and control participants (P > 0.05). There were no significant correlations between central cornea stromal thickness and anterior scleral thickness in myopic participants (P > 0.05). Conclusions: The thickness of anterior wall structures and preocular tear film of patients with moderate to high myopia are not statistically different compared with those of healthy controls.

Choroidal thickness changes after dynamic exercise as measured by spectral-domain optical coherence tomography

Purpose: To measure the choroidal thickness (CT) after dynamic exercise by using enhanced depth imaging optical coherence tomography (EDI-OCT). Materials and Methods: A total of 19 healthy participants performed 10 min of low-impact, moderate-intensity exercise (i.e., riding a bicycle ergometer) and were examined with EDI-OCT. Each participant was scanned before exercise and afterward at 5 min and 15 min. CT measurement was taken at the fovea and 1000 μ away from the fovea in the nasal, temporal, superior, and inferior regions. Retinal thickness, intraocular pressure, ocular perfusion pressure (OPP), heart rate, and mean blood pressure (mBP) were also measured. Results: A significant increase occurred in OPP and mBP at 5 min and 15 min following exercise (P ˂ 0.05). The mean subfoveal CT at baseline was 344.00 ± 64.71 μm compared to 370.63 ± 66.87 μm at 5 min and 345.31 ± 63.58 μm at 15 min after exercise. CT measurements at all locations significantly increased at 5 min following exercise compared to the baseline (P ˂ 0.001), while measurements at 15 min following exercise did not significant differ compared to the baseline (P ˃ 0.05). There was no significant difference in retinal thickness at any location before and at 5 min and 15 min following exercise (P ˃ 0.05). Conclusion: Findings revealed that dynamic exercise causes a significant increase in CT for at least 5 min following exercise.

Choroidal thickness and retinal vascular caliber correlations with internal carotid artery Doppler variables.

Decreased retinal arteriolar caliber and increased retinal venular caliber have been associated with increased cardiovascular mortality. This study aimed to evaluate correlations of choroidal thickness and retinal vascular caliber measurements with internal carotid artery (ICA) Doppler ultrasound variables.