Leyla Asena

Evaluation and comparison of the new swept source OCT-based IOLMaster 700 with the IOLMaster 500

Purpose To compare the measurements and failure rates obtained with a new swept source optical coherence tomography (OCT)-based biometry to IOLMaster 500. Setting Eye Clinic, Baskent University Faculty of Medicine, Ankara, Turkey. Design Observational cross-sectional study and evaluation of a new diagnostic technology. Methods 188 eyes of 101 subjects were included in the study. Measurements of axial length (AL), anterior chamber depth (ACD), corneal power (K1 and K2) and the measurement failure rate with the new Zeiss IOLMaster 700 were compared with those obtained with the IOLMaster 500. The results were evaluated using Bland–Altman analyses. The differences between both methods were assessed using the paired samples t test, and their correlation was evaluated by intraclass correlation coefficient (ICC). Results The mean age was 68.32±12.71 years and the male/female ratio was 29/72. The agreements between two devices were outstanding regarding AL (ICC=1.0), ACD (ICC=0.920), K1 (ICC=0.992) and K2 (ICC=0.989) values. IOLMaster 700 was able to measure ACD AL, K1 and K2 in all eyes within high-quality SD limits of the manufacturer. IOLMaster 500 was able to measure ACD in 175 eyes, whereas measurements were not possible in the remaining 13 eyes. AL measurements were not possible for 17 eyes with IOLMaster 500. Nine of these eyes had posterior subcapsular cataracts and eight had dense nuclear cataracts. Conclusions Although the agreement between the two devices was excellent, the IOLMaster 700 was more effective in obtaining biometric measurements in eyes with posterior subcapsular and dense nuclear cataracts.

The effect of topical bevacizumab as an adjunctive therapy for corneal neovascularization

Editor, A lthough recent research on human cornea showed promising results regarding the efficacy of topical bevacizumab on corneal neovascularization (NV) (Kim et al. 2008; Dastjerdi et al. 2009), many aspects such as patient selection, long-term safety and efficacy are yet to be determined. Here, we report our experience with topical bevacizumab in the treatment of corneal NV. The records of all patients who were treated with topical bevacizumab for corneal NV between July 2007 and August 2010 were reviewed. Inclusion criterion was progressive corneal NV despite aggressive systemic and local treatment including topical corticosteroids, topical cyclosporine, autologous serum eye drops and topical vitamin A (Table 1). Bevacizumab eye drops were added to the ongoing therapy at a dose of 5 mg ⁄ml qid, as the minimal effective dose was defined as 4 mg ⁄ml previously (Habot-Wilner et al. 2010). Patients were examined at weekly intervals. Treatment with bevacizumab was terminated when no further regression of corneal NV was observed for the last 4 weeks. The extent of corneal NV was evaluated by standardized digital slit-lamp photographs (16· magnification) taken before treatment and at each visit. The neovascularized area and the total corneal area were calculated in terms of pixels by an image analysis software (imagej 1.44p, Wayne Rasband, National Institutes of Health, Bethesda, MD, USA). Neovascularization regression percentage (NRP) was calculated for pretreatment and last visit images by using the formula [(neovascularized area % before therapy-neovascularized area % after therapy) ⁄neovascularized area % before therapy] · 100. The patients were separated into two groups: group 1 (good responders) involved the first eight patients showing the highest reduction in the percentage of the vascularized area with therapy and group 2 (poor responders) involved the other eight patients on the bottom of the list, when ranked according to the regression of neovascularization. The study group consisted of 16 patients (11 men, 5 women) with corneal NV because of different aetiologies. During treatment, varying degrees of regression in the vascularized corneal area were identified in all patients and no further vessel outgrowth was observed. The mean NRP was 29.6 ± 23% overall (range, 1.8– 77.4%), 49.8 ± 15.5% (range, 35.9– 77.4%) in group 1 (good responders) and 9.4 ± 5.7% (range, 1.8 ± 17.3%) in group 2 (poor responders). The mean visual acuity (logMAR) before treatment was 0.50 ± 0.39 (range, 0.0–1.3), which significantly increased to a mean of 0.34 ± 0.19 (range, 0.0–0.7) at the end of the follow-up (p = 0.018, Wilcoxon signed-ranks test) (Table 1). The mean duration of corneal NV before the initiation of topical bevacizumab therapy was 20.2 ± 23.4 weeks (range, 1–64). The patients in the good-responders group had the corneal NV for a significantly shorter duration before treatment (8.0 ± 11.6 weeks), compared to the poor-responders group (32.4 ± 26.4 weeks) (p = 0.028, Mann–Whitney U-test) (Table 1). The mean age of the patients in the goodresponders group (29.6 ± 10.9 years) was significantly lower than the poorresponders group (47.4 ± 14.4 years) (p = 0.01,5 Mann–Whitney U-test). The duration of therapy was longer in the good-responders group who had younger neovessels; however, this difference was not statistically significant (p = 0.195, Mann–Whitney Utest) (Table 1). Ocular surface side effects were neither reported by patients nor observed during the visits. Our study showed that early treatment of actively growing vessels and lower patient age at the time of therapy showed a significantly better outcome, suggesting that the short duration of corneal NV and younger age are good prognostic indicators. Previous investigations showed increased expression of VEGF and its receptors in actively growing vessels (Bock et al. 2008). It is also known that anti-VEGF agents have an inhibitory effect on mural cell recruitment and thus vascular maturation (Greenberg & Cheresh 2009), which also explains the more potent effect of topical bevacizumab on more immature vessels, as observed in our study.

Enhanced depth imaging optical coherence tomography features in a young case of primary hyperoxaluria Type 1.

PURPOSE To describe the enhanced depth imaging optical coherence tomography findings in a very young case of Type 1 primary hyperoxaluria. METHODS Observational case report of a young patient who underwent clinical examination and enhanced depth imaging optical coherence tomography evaluation. RESULTS A 4-year-old boy with a history of Type 1 primary hyperoxaluria and resulting chronic renal failure was referred to us for ophthalmologic examination. There were no ocular symptoms when he was referred to us. Fundus examination showed deposition of calcium oxalate crystals at the posterior pole located symmetrically in both eyes. Enhanced depth imaging optical coherence tomography evaluation revealed hyperreflective structures, localized under the photoreceptor inner segment/outer segment junction, and over the retinal pigment epithelium, consistent with deposition of oxalate crystals. There were no oxalate crystals in the superficial retinal layers, and we observed no evidence of deposition of oxalate crystals in choroid with enhanced depth imaging optical coherence tomography. CONCLUSION We could not demonstrate any oxalate deposits in the choroid with enhanced depth imaging optical coherence tomography in this young case of primary hyperoxaluria Type 1. This may be related to the young age of our patient, and the amounts of the crystalline deposition may increase in the years ahead.

Human Breast Milk Drops Promote Corneal Epithelial Wound Healing

ABSTRACT Purpose: To investigate the effects of human breast milk on corneal epithelial wound healing. Methods: The effects of human breast milk on epithelial healing is compared with autologous serum and artificial tears on 24 female Bal-b/C mice. A central corneal epithelial defect was created using a 2 mm trephine. Four groups were formed. By a random pick-up, topical human breast milk 4 × 1 was given to Group 1, topical mouse autologous serum 4 × 1 was applied to Group 2, and preservative-free artificial tears 4 × 1 was applied to Group 3.Group 4 was evaluated as control. Biomicroscopical examination was performed on days 1, 2, and 3. Mice were sacrificed on the third day. Histopathological and electron microscopic examinations were performed as well. Results: The fastest and best healing group was Group 1, followed by Group 2. Re-epithelization was not complete even at the end of the second day in groups 3 and 4. Conclusions: The rich content of human breast milk may be an alternative to epithelial healers and artificial tears.

Effect of dry eye on Scheimpflug imaging of the cornea and elevation data

OBJECTIVE To evaluate the effect of dry eye on Scheimpflug imaging of the cornea and elevation data. DESIGN Prospective observational study. PARTICIPANTS Scheimpflug images of 50 patients with dry eye who were being tested for eligibility for corneal refractive surgery were screened. Twelve eyes of 12 patients with abnormal Belin/Ambrosio enhanced ectasia display (BAD) anterior elevation difference were included in the study. The patients had no history of contact lens wear or any other sign of ectasia. METHODS Peak central corneal densitometry value, corneal volume, pachymetry at the thinnest point, and BAD anterior elevation difference value at the centre of the 9 mm zone were recorded before and after 4 weeks of dry eye treatment. Measurements were compared with the Wilcoxon signed rank test. RESULTS The mean corneal peak densitometry and volume were similar before and after therapy (p = 0.465 and p = 0.441, respectively). The mean anterior elevation difference value at the centre of the 9 mm zone before treatment (6.67 ± 1.72 µm) was significantly higher than the mean post-treatment value (4.00 ± 1.48 µm) (p = 0.002). The mean pachymetry at the thinnest location after treatment (548 ± 11.0) was significantly higher than the pretreatment value (538 ± 8.5) (p = 0.027). CONCLUSIONS BAD anterior elevation differences and pachymetric measurements may be affected by ocular surface or tear film abnormalities associated with dry eye disease. Repeated evaluations after treatment may reveal normal results.

Changes in Anterior Chamber Depth after Phacoemulsification in Pseudoexfoliative Eyes and their Effect on Accuracy of Intraocular Lens Power Calculation.

Objectives: To compare anterior chamber depth (ACD) changes after phacoemulsification surgery in patients with pseudoexfoliation syndrome (PEX) and normal patients using an anterior segment imaging method. Another aim of this study was to evaluate the effect of these changes on the accuracy of intraocular lens (IOL) power calculation and postoperative refraction. Materials and Methods: Twenty-two eyes of 22 patients with PEX and 30 eyes of 30 normal patients who underwent uneventful phacoemulsification surgery and IOL implantation were included in the study. The ACD of all patients was evaluated preoperatively and at 3 months postoperatively with the ALLEGRO Oculyzer (WaveLight® Oculyzer™ II, Alcon, Novartis)-Scheimpflug imaging system. Results: The postoperative mean ACD values were significantly larger than the preoperative ACD values in both groups (p<0.001 for both groups). The pre- to postoperative change in ACD was 0.46±0.3 mm in the PEX group, which was a larger change than seen in the normal patients (0.12±0.1 mm) (p=0.04). The mean absolute errors (MAE) calculated with different IOL formulas (SRK/T, Haigis, Hoffer and Holladay 1 formulas) were comparable and no statistically significant difference was observed between the two groups (p=0.21). Conclusion: Phacoemulsification induces more significant ACD changes in patients with PEX compared to normal patients. However, the MAE did not differ significantly between the groups.

Descemetʼs Membrane Endothelial Keratoplasty (DMEK): 6-Month Clinical Outcomes

Introduction Our purpose was to report the clinical outcomes of Descemets membrane endothelial keratoplasty (DMEK), at the postoperative 6th month. Patients and Methods Patients who underwent DMEK at Baskent University Faculty of Medicine, Department of Ophthalmology, between 2016 and 2017 were included in the study. Patient demographics, etiology of endothelial dysfunction, best corrected visual acuity, central corneal thickness, graft survival, intraoperative and postoperative complications and postoperative interventions were recorded. Results Six eyes of 6 patients (4 female, 2 male) with a mean age of 53.4±12.7 were included. Etiology of endothelial dysfunction was corneal endothelial distrophy in 3 patients, pseudophakic bullous keratopathy in 2 patients and endothelial graft failure after previous penetrating keratoplasty in 1 patient. Pre-stripped descemet’s membranes obtained from the Ankara State Hospital Eye Bank were used. Mean preoperative Snellen best corrected visual acuity (BCVA) and central corneal thickness (CCT) were 0.24±0.15 and 625.5±97.4 &mgr;m. Mean BCVA increased to 0.67±0.26 (p=.02) in the first month and to 0.84±0.11 (p<.01) at the end of the follow up. Mean CCT decreased to 546.6±28.4 &mgr;m (p=.03). Graft detachment was observed in 2 cases on the first and third postoperative days and the grafts were reattached succesfully by injection of air into the anterior chamber. There were no intraoperative complications. Five corneas were clear at the end of the follow-up. One patient had a re-DMEK and a following penetrating keratoplasty. Conclusions DMEK provides a new and exciting option for endothelial transplantation and has the potential to become the primary procedure for surgical management of Fuchs’ endothelial dystrophy and corneal endothelial disease. Rapid visual rehabilitation with few and managable complications and good visual outcomes are the major advantages of this procedure.

Results of Combined Penetrating Keratoplasty and Implantation of Posterior Chamber Intraocular Lenses

Introduction Our purpose was to evaluate the clinical outcome in 14 patients (14 eyes) who underwent penetrating keratoplasty and scleral-fixation of an intraocular lens (IOL). Materials and Methods Charts of the patients who underwent combined penetrating keratoplasty and implantation of scleral-sutured posterior chamber intraocular lenses between January 2010 and January 2015 were reviewed. Gender and age of the patients, indication for surgery, pre- and post-operative best corrected visual acuity, diopter of implanted IOL, postoperative refraction, duration of follow-up and complications were recorded. Results The mean age of the patients was 71.2±15.0 years and the female/male ratio was 11/3. The indications for penetrating keratoplasty with scleral-fixation of an intraocular lens were pseudophakic corneal edema in 6 patients (43%), aphakic corneal edema in 2 patients (14%), trauma in 3 patients (21%), and corneal scars in 3 patients (21%). Patients with pseudophakic corneal edema underwent IOL exchange and penetrating keratoplasty. Patients with lens subluxation underwent cataract extraction and penetrating keratoplasty in the same operation session. Preoperative visual acuity was p+p+ in 2 eyes (14%), hand motion in 5 eyes (36%), finger counting in 4 eyes (28%) and 20/400 in 3 eyes (21%). The mean duration of follow-up was 14.8±8.5 months. Postoperative spectacle- corrected visual acuity of 20/200 or better was observed in 8 eyes (57%). The postoperative mean spherical equivalent was 2,53± 6,00 D and the mean cylinder was 3,78±1,66 D. At the end of follow-up, 6 corneal grafts remained clear. Graft failure was observed in 7 eyes (50%) and reccurrence of herpetic stromal keratitis was observed in 1 eye (7%). Glaucoma was observed in 9 eyes (64%) and graft failure occured as a result, in 5 of these. Conclusions Trans-scleral fixation of intraocular lenses combined with penetrating keratoplasty is associated with favorable visual outcomes in eyes with keratopathy and lacking posterior capsular support. However, glaucoma is an important and common complication frequently leading to graft failure.

Corneal Epithelial Wound Healing and Management Strategies

Careful treatment of corneal epithelial defects is essential for maintaining the barrier function of the cornea against infective microorganisms and providing a transparent refractive surface which are necessary for good visual acuity. Wound healing in the corneal epithelium is regulated by a range of cytokines, growth factors, matrix proteins and proteases. Numerous standard therapies and a number of new therapies can be used in an attempt to heal persistent corneal epithelial defects. Conventional therapies include frequent lubrication, prophylactic antibiotics, eye patching and bandage contact lenses. Human serum-derived therapies, punctal occlusion, therapeutic contact lenses and surgical treatment options are reserved for selected cases. Human breast milk drops can be used as an alternative therapeutic agent due to the rich content including fibronectin, interleukin-6, epidermal growth factor, tumour necrosis factor-α and substances that have a role in epithelial and stromal wound healing such as transforming growth factor-β, insulin-like growth factor, lipids and vitamins.

Comparison of Keratometry Obtained by a Swept Source OCT-Based Biometer with a Standard Optical Biometer and Scheimpflug Imaging

ABSTRACT Purpose: To assess agreement of a swept source-optical coherence tomography (SS-OCT) based Biometer with a standard IOLMaster device and Scheimpflug Imaging (SI) to acquire keratometric measurements in cataract patients. Methods: In this prospective comparative study, 101 eyes of 101 cataract surgery candidates, aged 24–81 years, were sequentially examined using three devices. Keratometry values at the flat (K1) and steep (K2) axis, mean corneal power (Km) and magnitude of corneal astigmatism as well as J0 and J45 vectoral components of astigmatism obtained with the SS-OCT based biometer (IOLMaster 700) were compared with those obtained with the IOLMaster 500 and SI. The agreement between measurements was evaluated by the Bland–Altman method, intraclass correlation coefficients (ICCs) and repeated-measures analysis of variance. Results: Mean K1 values from the three devices were similar (p = 0.09). Mean K2 and Km values of IOLMaster 700 were higher than SI and lower than IOLMaster 500 (p = 0.04 for K2 and p = 0.02 for Km). There was a strong correlation between K1, K2, Km and magnitude of astigmatism obtained with all devices (r ≥ 0.80 and p < 0.01). The 95% limits of agreement (LoA) width for each keratometric value were highest for the comparison between IOLMaster 500 and SI and lowest for the comparison between IOLMaster 700 and 500. The mean differences (width of 95% LoA) for J0 and J45 vectoral components were 0.005 (2.19) and 0.12 (2.92) for the measurements obtained by IOLMaster 700 vs IOLMaster 500 and 0.06 (1.79) and 0.02 (1.58) for the measurements obtained by IOLMaster 700 vs SI, respectively. Conclusions: With ICCs close to 1, the agreement between all devices was excellent for keratometric measurements. Mean K2, Km and astigmatism measurements from IOLMaster 700 were lower than IOLMaster 500 and higher than SI. However, the differences were quite small and are not expected to affect the final IOL power.