Abdullah Ilhan

Autologous Serum Eye Drops Accelerate Epithelial Healing After LASEK.

I congratulate Hondur et al. for their study entitled ‘‘Autologous Serum Eye Drops Accelerate Epithelial Healing After LASEK’’. The authors investigated autologous serum on the rate of epithelial healing and clinical results after laser epithelial keratectomy (LASEK) and found that autologous serum eye drops are effective on enhancing epithelial healing and improving patient comfort. Human tear film contains various growth factors and essential components secreted by the lacrimal gland. Transforming growth factor-b, basic fibroblast growth factor, epidermal growth factor, neurotrophic factors and vitamin A are one of these bioactive substances. They play critical roles in maintaining the health of ocular surface structures. It has been revealed that blood derivatives include a variety of neurotrophic factors and growth factors similar to tear components. The pH and osmolarity of serum are very similar to ocular surface. I assume that the superiority of autologous serum to regular lubricant eye drops is related to these features. On the other hand, platelet-rich plasma could have been a more valuable adjunct than autologous serum as it contains more of the bioactive substances mentioned above in a smaller volume. Another issue is that the patients in the control group used artificial tears (Refresh Tears, Allergan) which contain oxychloro complex (Purite) as a preservative. Although oxychloro complex is generally accepted as safe and well-tolerated, using a preservative-free artificial tear would be a better choice in order to avoid its possible negative effects on epithelial regeneration. Finally, I appreciate the authors for this valuable study and their contribution to the literature.

Morphological features in eyes with endophthalmitis after cataract surgery–histopathology and optical coherence tomography assessment

To assess the ocular damage that occurs in eyes with postoperative endophthalmitis after cataract surgery (PE) based on optical coherence tomography (OCT) retinal scans of PE eyes and histological specimens of eyes removed due to PE.

Acute effect of cigarette smoking on pupil size and ocular aberrations: a pre- and postsmoking study.

Aim. To evaluate the acute effects of cigarette smoking on photopic and mesopic pupil sizes and wavefront aberrations. Methods. Cigarette smoker volunteers were recruited in the study. Photopic and mesopic pupil sizes and total ocular aberrations were measured before smoking and immediately after smoking. All volunteers were asked to smoke a single cigarette containing 1.0 mg nicotine. Pupil sizes and total ocular aberrations were assessed by optical path difference scanning system (OPD-Scan II ARK-10000, NIDEK). Only the right eyes were considered for statistical analysis. The changes of pupil size and total ocular aberrations after smoking were tested for significance by Wilcoxon signed ranks test. Results. Mean photopic pupil size decreased from 3.52 ± 0.73 mm to 3.29 ± 0.58 mm (P = 0.001) after smoking. Mean mesopic pupil size was also decreased from 6.42 ± 0.75 mm to 6.14 ± 0.75 mm after smoking (P = 0.001). There was a decrease in all the measured components of aberrations (total wavefront aberration, higher-order aberration, total coma, total trefoil, total tetrafoil, total spherical aberration and total higher-order aberration) after smoking; however the differences were insignificant for all (P > 0.05). Conclusion. Our results indicate that pupil constricts after smoking. On the other hand, smoking does not alter ocular aberrations.

Detection of retinal nerve fibre layer degeneration in patients with Alzheimer's disease using optical coherence tomography: searching new biomarkers

Editor, W e congratulate Bambo et al. (Bambo et al. 2014) for their study entitled ‘Detection of retinal nerve fibre layer degeneration in patients with Alzheimer’s disease using optical coherence tomography: searching new biomarkers’. The authors compared retinal nerve fibre layer (RNFL) thickness differences between patients with Alzheimer’s disease and healthy controls using the two most commonly available spectral-domain optical coherence tomography (SD-OCT) machines. The authors found significant thinning in superior and inferior RNFL in Cirrus OCT (Carl Zeiss, Meditec, Inc., Dublin, Ireland) and significant thinning in the inferior and infero-temporal RNFL in Spectralis OCT (Heidelberg Engineering, Inc., Carlsbad, CA, USA). The authors also stated that they included the visual acuity and colour vision examinations of the patients. Previously, we studied whether RNFL thickness may be used as a biomarker in the early diagnosis of multiple sclerosis (Gundogan et al. 2007). We found that a clinical finding – colour vision assessment – is better correlated with the disease activity. At this point, we want to ask to the authors to perform a correlation analysis between the visual acuity, colour vision, RNFL thickness and the clinical stage of the Alzheimer’s disease activity to explore which parameter is best-correlated with the disease severity.

In Response to: “Khochtali S, Abroug N, Kahloun R, et al. Pattern of Acute Retinal Necrosis in a Referral Center in Tunisia, North Africa”

Wehave readwith interest the article entitled “Pattern of acute retinal necrosis in a referral center in Tunisia, North Africa” by Khochtali et al. The authors described the clinical features and visual outcome of acute retinal necrosis (ARN) in 12 patients in a referral center in Tunisia. Their findings provide clues for developing better treatment strategies for such tough cases. We would like to share our reservations about the study. Progressive outer retinal necrosis (PORN) and ARN are classified in necrotizing herpetic retinopathies characterized by mild to severe immune dysfunction. However, PORN has some distinguishing features. It is mostly seen in immunocompromised patients, unlike ARN, which is known to affect immunocompetent patients. Besides, in PORN cases varicella zoster virus (VZV) is the most commonmicroorganism. It is also called ‘VZV retinitis’. The authors stated that the medical history of the patients had shown no immune-altered conditions. On the other hand, four patients (33.3%) had received systemic corticosteroids; two of the four patients had intravenous corticosteroid therapy, and one of them was at the age of 70. Systemic corticosteroids and age above 60 are well-known factors for immunodeficiency. Moreover, PCR analysis of three patients showed VZV. Therefore, we think that some of the cases might have been defined as PORN and a more inclusive term, such as ‘necrotizing viral retinitis’ would have been more suitable. Finally, we would like to express our gratitude to the authors for this study and their valuable contribution to the literature.

Comment on "Choroidal Thickness in Patients with Mild Cognitive Impairment and Alzheimer's Type Dementia".

The authors congratulate Bulut et al. [1] for their study entitled “Choroidal Thickness in Patients with Mild Cognitive Impairment and Alzheimers Type Dementia.” The authors investigated choroidal and macular thickness in Alzheimers type dementia (ATP), mild cognitive impairment (MCI), and control healthy subjects. The findings are impressive and show that choroidal thickness in the subfoveal, nasal, and temporal retinal regions are all significantly thinner in ATP and MCI patients with respect to control eyes. However, the authors did not find any significant change in terms of macular thickness. The findings are really important, because longitudinal choroidal thickness data may be used in suspected patients. We realized that the authors have included both eyes of the participants in the statistical analyses. We want to emphasize that including both eyes of participants in the statistical analyses violates the independence of the variables when using ANOVA and/or independent samples t-test. Although that is true, we think that including only one eye of participants will not possibly affect the results, because the differences are really big between the groups. We want to ask the authors whether they have retinal nerve fiber layer thickness and/or ganglion cell complex data of the patients and make statistics between the groups. It is plausible that any central nervous system pathology may initially affect retinal nerve fibers compared to other ocular structures including choroid. In addition, we see that the authors investigated the correlations between mini-mental state examination (MMSE) and choroidal thickness by including all the participants. We kindly ask the authors to perform these statistics in each group. The result of those statistics can tell us whether MMSE may be used in the follow-up of patients in terms of progression analysis.

Pharmacotherapy for treatment of retinal vein occlusion

We congratulate Sarao et al. for their article entitled ‘Pharmacotherapy For Treatment Of Retinal Vein Occlusion (RVO)’ [1]. The authors presented an update and a brief review on the current treatment modalities and promising alternatives for RVO. We would like to mention about matrix metalloproteinase (MMP)-9 as a potential future target. MMP-9 is involved in the breakdown and re-modeling of extracellular matrix in multiple physiological and pathological processes such as angiogenesis, wound healing, cell migration, and etc. Studies about the role of MMP-9 in retinal vascular disorders are few. It has been demonstrated that MMP-2 and MMP-9 may trigger apoptosis of retinal capillary cells, mitochondrial dysfunction and neovascularization in diabetic retinopathy. Grieshaber et al. revealed the role of MMP-9 to optic disc and peripapillary retinal hemorrhages [2]. In ischemic stroke or intracerebral hemorrhage, there is an extensive expression of MMP-9 that is related to excitotoxicity, apoptosis, neural damage, hemorrhagic transformation and blood-brain barrier disruption that results in tissue edema. We hypothesize that MMP-9 may be a possible cause of retinal edema similar to stroke. Bertelmann et al. have demonstrated the elevation of intravitreal functional plasminogen in eyes with central and branch RVO and correlated with the extent of blood--retina barrier damage [3]. This pathological process could be mediated by MMP-9 similar to stroke. Meanwhile, Tuuminen et al. recently found that intravitreal levels of MMP-9 is significantly elevated in patients with RVO patients [4]. In regard to data mentioned above, we assume that MMP-9 can be considered as a rational target for RVO treatment. The inhibition of MMP-9 interfere with degradation of basement membrane and related intimal hyperplasia. This inhibition contributes in the prevention of vascular stenosis [5]. So targeting MMP-9 may be protective as well.

Re: A prospective observational study of techniques to remove corneal foreign body in the emergency department

Dear Editor, We have read the article entitled ‘A prospective observational study of techniques to remove corneal foreign body in the emergency department.’ by Quirke et al 1 with interest. We congratulate the authors that they called attention to an important issue in the emergency settings. The study aimed to compare the slit-lamp-aided technique of superficial corneal foreign body (FB) removal with direct removal without the aid of a slit-lamp biomicroscopy performed by emergency physicians. In …

Therapeutic effects of proanthocyanidin and coenzyme Q10 on nitrogen mustard-induced ocular injury

PURPOSE Nitrogen mustard (NM) is a devastating casualty agent in chemical warfare. There is no effective antidote to treat NM-induced ocular injury. We aimed to assess the effects of proanthocyanidin (PAC) and coenzyme Q10 (CoQ10) on NM-induced ocular injury. METHODS Eighteen male rats were divided into the following 4 groups: NM, NM + PAC, NM + CoQ10, and control. The 3 NM groups received a single dose of NM (0.02 mg/μL) on the right eye to induce ocular injury. The control group received saline only. Thirty minutes after the application of NM, the NM + PAC group received PAC (100 mg/kg) via gastric gavage, while the NM + CoQ10 group received CoQ10 (10 mg/kg) via intraperitoneal injection. PAC and CoQ10 were administered once a day for 5 consecutive days. The rats were then sacrificed. Macroscopic images of the eyes were examined and eye tissues were collected for histology. RESULTS The treatment groups were compared to the control group with regard to both corneal opacity and lid injury scores. The findings were not significantly different for both the NM + PAC and NM + CoQ10 groups. In both the NM + PAC and NM + CoQ10 groups, the histological changes seen in the NM group demonstrated improvement. CONCLUSIONS Our results indicate that PAC and CoQ10 treatments have therapeutic effects on NM-induced ocular injury in a rat model. PAC and CoQ10 may be novel options in patients with NM-induced ocular injury.

Neuroretinitis secondary to Bartonella henselae in the emergent setting

We have read the article entitled “Neuroretinitis secondary to Bartonella henselae in the emergent setting” byUrsula et al [1]with interest. We congratulate the authors that they called attention of the emergency physicians to this rare but momentous condition. We would like to ask for further details and make a contribution to the article. Immunoglobulin titers in the acute and convalescent periods are essential for the diagnosis of patients with a suspicious Bartonella neuroretinitis [2]. Acute infection can be detected by elevated IgM titers. In the later phases, IgG begins to rise andmay remain positive for about 2 years. Centers for Disease Control and Prevention accepts positive IgM or highly elevated IgG as a proof of cat-scratch disease [3]. Polimerase chain reaction in blood samples and aqueous humor may have been used as a strong proof [4]. Therefore, we ask the authors results of the serologic tests that will support the diagnosis. The use of steroids in Bartonella neuroretinitis is controversial [5]. There are several studies reporting the insignificant effect of steroids. However, some authors claim that this inefficacy may be related to the selection bias. Those authors report that steroids are generally given to patients with relatively worse clinical presentations [5]. The case reported by Ursula et al [1] had severe visual loss at the presentation, but the resultant vision was 20/20. We want to ask the attitudes of the authors if the use of steroid (started by the infectious disease specialist before the accurate diagnosis) played a critical role in the recovery. Finally, we would like put emphasis on another distinctive characteristic of the case. Optic neuropathy, neuroretinitis, vitritis, focal retinitis, choroiditis, retinal gray spots, macular hole, retinal vasculitis, and retinal vascular occlusions are possible posterior segment involvements of neuroretinitis. Interestingly, the authors reported choroidal detachment in the case. To the best of our knowledge, this is the first neuroretinitis case presenting with choroidal detachment. We think that this is another unique feature of the case.