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Recent eLetters

Displaying 1-10 letters out of 532 published

  1. Re:Comment on: Choroidal structure in eyes with drusen and reticular pseudodrusen determined by binarisation of optical coherence tomographic images

    Dear Editor We thank Drs Uzun and Pehlivan for their interest in our article,1 and we welcome this opportunity to address their concerns. As pointed out, there are several factors that may induce fluctuation of choroidal thickness such as the diurnal effect, systemic diseases (endocrine, cardiovascular, rheumatologic, and inflammatory), intraocular pressure, refractive status, systemic blood pressure, body mass index, alcohol, smoking, and caffeinated beverage consuming.2-8 A limitation of our study is the retrospective design, therefore all of these parameters cannot be tested. In our series, the refractive error should not be considered as a potential confounding factor because we included patients with an axial length between 23.5 and 26.5 mm. Regarding intraocular pressure, a recent study 5 showed a significant diurnal fluctuation, but no correlation with choroidal thickness was detected in other reports.3,7 All of the studies 2-8 determining the diurnal variation of choroidal thickness were conducted in healthy subjects with healthy choroid while in our series we evaluated patients with drusen and reticular pseudodrusen in which remodeling of the choroid has been demonstated.1,9 In particular in patients with reticular pseudodrusen the choroid is significantly thinner compared to control subjects.1,9 As a result, thinner choroid with less blood supply may be less influenced by diurnal variation or systemic, local and environmental factors. Of note, a recent publication evaluated the diurnal variations in luminal and stromal areas of choroid in normal eyes by binarisation technique and demonstrated significant variations in the central choroidal thickness and luminal area but not in the stromal area.9 In our study we found that the stromal area was more represented in eyes with reticular pseudodrusen, suggesting less influence by diurnal variation or systemic, local and environmental factors and a possible role of choroidal vascular depletion and fibrotic replacement in the pathogenesis and disease progression.1 The insightful comments of Drs Uzun and Pehlivan are worth of considerable for further prospective studies with larger sample size, especially in patients with early age related macular degeneration and reticular pseudodrusen, and longer follow-up periods are needed to confirm if systemic, local and environmental factors should be considered as potential confunding effects on the choroid examination. ? References 1. Corvi F, Souied EH, Capuano V, et al. Choroidal structure in eyes with drusen and reticular pseudodrusen determined by binarisation of optical coherence tomographic images. Br J Ophthalmol. 2016. pii: bjophthalmol- 2016-308548. 2. Tan KA, Gupta P, Agarwal A, Chhablani J, Cheng CY, Keane PA, et al. State of science: Choroidal thickness and systemic health. Surv Ophthalmol 2016; doi: 10.1016/j.survophthal.2016.02.007. 3. Toyokawa N, Kimura H, Fukomoto A, Kuroda S. Difference in morning and evening choroidal thickness in Japanese subjects with no chorioretinal disease. Ophthalmic Surg Lasers Imaging. 2012;43:109e14 4. Usui S, Ikuno Y, Akiba M, Maruko I, Sekiryu T, Nishida K, et al. Circadian changes in subfoveal choroidal thickness and the relationship with circulatory factors in healthy subjects. Invest Ophthalmol Vis Sci 2012;53:2300-7. 5. Lee SW, Yu SY, Seo KH, Kim ES, Kwak HW. Diurnal variation in choroidal thickness in relation to sex, axial length, and baseline choroidal thickness in healthy Korean subjects. Retina 2014;34:385-93. 6. Chakraborty R, Read SA, Collins MJ. Diurnal variations in axial length, choroidal thickness, intraocular pressure, and ocular biometrics. Invest Ophthalmol Vis Sci. 2011;52:5121e9. 7. Tan CS, Ouyang Y, Ruiz H, Sadda SR. Diurnal variation of choroidal thickness in normal, healthy subjects measured by spectral domain optical coherence tomography. Invest Ophthalmol Vis Sci. 2012;53:261e6 8. Kinoshita T, Mitamura Y, Shinomiya K, et al. Diurnal variations in luminal and stromal areas of choroid in normal eyes. Br J Ophthalmol. 2016 Jun 13. pii: bjophthalmol-2016-308594.6 9. Querques G, Querques L, Forte R, et al. Choroidal changes associated with reticular pseudodrusen. Invest Ophthalmol Vis Sci 2012;53:1258-63.

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  2. Comment on: Predicting outcomes to anti-vascular endothelial growth factor (VEGF) therapy in diabetic macular oedema: a review of the literature

    Dear Editor, We read and reviewed the article entitled as "Predicting outcomes to anti- vascular endothelial growth factor (VEGF) therapy in diabetic macular oedema: a review of the literature'' by Ashraf et al. with great interest [1]. In that comprehensive study, the authors reviewed the studies that investigated demographic, clinical, optical coherence tomography (OCT), and fluorescein angiography results that could predict the outcomes of the anti-VEGF agents in patients with diabetic macular edema.

    Ashraf et al. suggested that choroidal thickness (CT) might also be utilized as a novel marker to predict outcomes of the treatment with anti- VEGF agents in patients with diabetic macular edema. However, we disagree with the authors at some important points.

    As Ashraf et al. have already indicated in their paper, CT is significantly variable in the patients with diabetic retinopathy. Although some studies stated that CT increased significantly, some others demonstrated that CT decreased significantly in patients with diabetic retinopathy. Even in some studies, CT has been found to be the same in the diabetic patients and the normal control group. Then what may be the causes of such conflicting results in CT measurements?

    First, choroid has a unique vascular anatomy and physiology [2]. It is one of the tissues that has the most excessive per-gram blood supply in the body. Therefore, various local, systemic, and environmental factors significantly affect CT [2,3].

    Second, various anatomic and pathological factors associated with eye significantly affect CT. In the literature, it has been indicated that local factors such as intraocular pressure, axial length, and refractive errors may affect CT [2,3]. Moreover, glaucoma, amblyopia, strabismus, and many other eye diseases and their treatments may affect CT.

    Third, many neurologic, rheumatologic, inflammatory, hematologic, endocrine, and vascular disease and their medications may significantly affect CT [3]. Additionally, physiologic conditions such as pregnancy and menstrual cycle also affect CT.

    Fourth, smoking, alcohol and caffeinated/decaffeinated beverages, diurnal variations as well as lightening conditions of the room where the CT measurement is performed may significantly affect CT [2,3].

    In contrast to Ashraf et al., we do not suggest CT as a suitable marker for patient follow-up, or a predictor for treatment outcomes. If the CT would be considered as a criterion, all local, systemic, and environmental factors should be standardized and optimized.

    References 1 Ashraf M, Souka A, Adelman R. Predicting outcomes to anti-vascular endothelial growth factor (VEGF) therapy in diabetic macular oedema: a review of the literature. Br J Ophthalmol. 2016; doi: 10.1136/bjophthalmol-2016-308388. 2 Nickla DL, Wallman J. The multifunctional choroid. Prog Retin Eye Res 2010;29:144-68. 3 Tan KA, Gupta P, Agarwal A, Chhablani J, Cheng CY, Keane PA, et al. State of science: Choroidal thickness and systemic health. Surv Ophthalmol 2016; doi: 10.1016/j.survophthal.2016.02.007.

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  3. Comment on: Choroidal structure in eyes with drusen and reticular pseudodrusen determined by binarisation of optical coherence tomographic images

    Dear Editor, We have read and reviewed the article entitled as "Choroidal structure in eyes with drusen and reticular pseudodrusen determined by binarisation of optical coherence tomographic images" by Corvi et al. with great interest [1]. The authors compared luminal and stromal areas of the choroid in eyes with drusen and reticular pseudodrusen (RPD), and investigated their changes over 24 months using optical coherence tomography (OCT). They found that the mean total choroidal, luminal, and stromal areas decreased similarly in eyes with drusen and RPD over the period of 24 months. The mean total choroidal, luminal, and stromal areas were reduced more in eyes with RPD when compared to the eyes with drusen, and the controls. We express our gratitude to the authors for this valuable study, and we would like to ask the authors some important points that may affect the study results.

    Owing to its unique anatomic structure, choroid is one of the most excessively vascularized tissues in the body. Accordingly, various local, systemic or environmental factors that affect vascular system influence choroid [2,3]. Although Corvi et al. referred a number of factors affecting choroid, we suggest that some important points should also be addressed in the paper.

    First, choroidal thickness (CT) has a significant diurnal variation. Animal studies have demonstrated that CT might increase up to 50% in an hour, and might decrease 100 ?m within 3-4 hours [3]. In a study, Usui et al. analyzed subfoveal CT of healthy individuals at three hours intervals, and discovered that CT demonstrated significant differences at all measurement points [4]. In that study, Usui et al. indicated that diurnal variation in CT might be up to 65 ?m (ranging between 8 and 65 ?m). Another study by Lee et al. that included 100 adults reported the mean amplitude of the diurnal variation in CT as 20.32 ? 10.40 ?m (ranging between 4 and 60 ?m) [5]. Therefore we would like to ask the authors whether they have considered diurnal variation of CT at baseline, and 24- month choroid measurements.

    Second, various systemic diseases (endocrine, cardiovascular, rheumatologic, and inflammatory), and their medications may significantly affect CT [2]. Since the participants of the study are old, those points should be indicated in the paper.

    Third, intraocular pressure and refractive status, which have well known effects on CT, should be indicated in the paper, and compared between the groups.

    Fourth, we suggest that some important parameters that affect CT like systemic blood pressure, and body mass index of the participants should also be addressed in the paper. Moreover, alcohol, smoking, and caffeinated beverage consuming of the participants should be asked for before OCT measurements.

    In summary, we suggest that the aforementioned factors affecting CT may also affect stromal and luminal areas of the choroid as well, and change the results of the study. We want to get the opinions of the authors in this regard.

    References 1 Corvi F, Souied EH, Capuano V, Costanzo E, Benatti L, Querques L, et al. Choroidal structure in eyes with drusen and reticular pseudodrusen determined by binarisation of optical coherence tomographic images. Br J Ophthalmol. 2016; doi: 10.1136/bjophthalmol-2016-308548. 2 Tan KA, Gupta P, Agarwal A, Chhablani J, Cheng CY, Keane PA, et al. State of science: Choroidal thickness and systemic health. Surv Ophthalmol 2016; doi: 10.1016/j.survophthal.2016.02.007. 3 Nickla DL, Wallman J. The multifunctional choroid. Prog Retin Eye Res 2010;29:144-68. 4 Usui S, Ikuno Y, Akiba M, Maruko I, Sekiryu T, Nishida K, et al. Circadian changes in subfoveal choroidal thickness and the relationship with circulatory factors in healthy subjects. Invest Ophthalmol Vis Sci 2012;53:2300-7. 5 Lee SW, Yu SY, Seo KH, Kim ES, Kwak HW. Diurnal variation in choroidal thickness in relation to sex, axial length, and baseline choroidal thickness in healthy Korean subjects. Retina 2014;34:385-93.

    Conflict of Interest:

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  4. Comment on: Anatomical effects of dexamethasone intravitreal implant in diabetic macular oedema: a pooled analysis of 3-year phase III trials

    eLetter Comment on: Anatomical effects of dexamethasone intravitreal implant in diabetic macular oedema: a pooled analysis of 3-year phase III trials Parul Chawla Gupta, MS; Jagat Ram, MS, FAMS Department of Ophthalmology Post Graduate Institute of Medical Education and Research, Chandigarh, India, 160012 Corresponding author Dr. Jagat Ram, MS, FAMS Professor and Head Department of Ophthalmology Post Graduate Institute of Medical Education and Research, Chandigarh, India, 160012 Email id: drjagatram@gmail.com Conflict of interest and source of funding- None declared

    Dear Editor, We read with interest the recent paper by Danis [1] and associates assessing the long-term effects of dexamethasone intravitreal implant (DEX implant) monotherapy on retinal morphology in diabetic macular edema (DME). While the study is indeed interesting, there are certain points we wish to highlight. Firstly, among the previously treated eyes what was the mean interval between DEX injection and any previous treatment since it may confound the results. A recent study by Chhablani [2] et al, showed significant difference (P= 0.016) between the longest treatment-free interval between the groups that is, 10.5? 7.8 and 7.0? 4.4 months among treatment naive and previously treated eyes, respectively. What was the longest treatment-free interval in previously treated and na?ve eyes post DEX implant in the present study? Secondly, how many patients had vitreomacular traction syndrome or epiretinal membrane? Thirdly, in a meta-analysis of observational studies carried out by Zhang and colleagues [3] evaluating the effect of insulin use on the risk of developing macular edema, it was seen that insulin use increased the risk of macular edema. In few studies [3, 4], the risk for macular edema was greater in patients receiving pioglitazone/rosiglitazone than in those who did not. In addition, combining pioglitazone with insulin was associated with an even greater risk for macular edema, with patients having a more than 11-fold increased risk compared with diabetic patients who did not receive the 2 drugs. Hence, the authors need to take into account the number of patients on oral hypoglycemic like pioglitazone/rosiglitazone and those who shifted to insulin therapy during follow up. History of aspirin use and ACE inhibitor use should be enquired as they are shown to be associated with a reduced risk of DME. Fourthly, "at the final study visit, the decline in the proportion of study eyes in this category was greater with DEX implant 0.7 mg (from 94.5% at baseline to 60.2%) and DEX implant 0.35 mg (from 94.8% to 58.7%) than with sham (from 95.9% to 71.6%)" and "the 10th percentile of time to two-step improvement in diabetic retinopathy severity was ?24 and ?13 months for the DEX implant 0.7 and 0.35 mg treatment groups versus ?24 months for sham". Do the authors imply that the 0.35 mg DEX implant is as efficacious as the 0.7 mg implant or does it suggest better sustained metabolic control in the patients receiving the 0.35 mg implant? Moreover, since systemic hypertension is a risk factor for the development and progression of both diabetic retinopathy and DME, and hyperlipidemia increases the risk of leakage and exudative deposits in the macula [5], blood pressure and lipid profile should have been recorded at baseline and at subsequent visits to assess whether improvement in macular edema was as a result of strict systemic control or as a result of the implant itself. Lastly, since steroids exacerbate cataractous changes, it would be interesting to know the lens status in the three groups at final follow up. References 1. Danis RP, Sadda S, Li XY, et al. Anatomical effects of dexamethasone intravitreal implant in diabetic macular oedema: a pooled analysis of 3- year phase III trials. Br J Ophthalmol 2016;100:796-801. 2. Chhablani J, Bansal P, Veritti D, et al. Dexamethasone implant in diabetic macular edema in real-life situations. Eye 2016;30:426-430. 3. Zhang J, Ma J, Zhou N, Zhang B, An J. Insulin Use and Risk of Diabetic Macular Edema in Diabetes Mellitus: A Systemic Review and Meta-Analysis of Observational Studies. Medical Science Monitor?: International Medical Journal of Experimental and Clinical Research. 2015;21:929-936. 4. Idris I, Warren G, Donnelly R. Association between thiazolidinedione treatment and risk of macular edema among patients with type 2 diabetes. Arch Intern Med 2012;172:1005-1011. 5. Gardner TW, Antonetti DA, Barber AJ, LaNoue KF, Levison SW. Diabetic retinopathy: more than meets the eye. Surv Ophthalmol. 2002; 47(suppl 2): S253-S262.

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  5. Comment on: Clinical outcomes of amniotic membrane transplantation in the management of acute ocular chemical injury

    eLetter Comment on: Clinical outcomes of amniotic membrane transplantation in the management of acute ocular chemical injury Parul Chawla Gupta, MS; Jagat Ram, MS, FAMS Department of Ophthalmology Post Graduate Institute of Medical Education and Research, Chandigarh, India, 160012 Corresponding author Dr. Jagat Ram, MS, FAMS Professor and Head Department of Ophthalmology Post Graduate Institute of Medical Education and Research, Chandigarh, India, 160012 Email id: drjagatram@gmail.com Conflict of interest and source of funding- None declared

    Dear Editor, We read with interest the recent paper by Westekemper and associates [1] analysing the morphological and functional outcomes of patients receiving AMT after ocular chemical burns. While the study is indeed interesting, we herein address important issues, some of which warrant further discussion. Firstly, as the authors stated in the abstract "In 37 eyes (51.4%), AMT was applied within the first 6 days after injury". However, in the manuscript it is mentioned that," thirty-seven eyes (50.0%) received the AMT within 6 days after trauma". Secondly, in the present study, the patients treated at University of Duisburg-Essen, Germany and the Newcastle University, UK were not matched as far as the treatment protocol was concerned. In Essen, oral ascorbic acid 1g twice daily, oral prednisolone starting at 150mg/day orally and artificial tear substitutes (hyaluronic acid 0.15%) up to every hour were given in addition to the what the patients received at Newcastle; which might have influenced the final outcomes after AMT. Hence, the beneficial outcomes reported in the study may not be completely attributed by the use of AMT alone. However, we strongly believe that the once a day dose of dexamethasone 0.1% or prednisolone 1% given to patients in Essen was grossly inadequate since frequent topical steroids [2] remain the mainstay of treatment in ocular chemical burns primarily in the early stages since they reduce inflammatory cell infiltration and stabilize neutrophilic cytoplasmic and lysosomal membranes. Thirdly, repeated AMTs were necessary in 27 eyes (37.5%) due to Persistent Epithelial Defect (PEDs) and 12 eyes (16.6%) required more than 2 AMTs. Interestingly, an alternative non-surgical approach to the management of acute ocular chemical burn can be fingerprick autologous blood which can be used for early healing of persistent epithelial defects as shown in a recent study by Wawrzynski et al [3].

    References 1. Westekemper H, Figueiredo FC, Siah WF, et al. Clinical outcomes of amniotic membrane transplantation in the management of acute ocular chemical injury. Br J Ophthalmol 2016;0:1-5. 2. Davis AR, Ali QH, Aclimandos WA, Hunter PA. Topical steroid use in the treatment of ocular alkali burns. Br J Ophthalmol 1997;81(9):732-734. 3. Wawrzynski J, H Mukherjee H, J Moore J, et al. Fingerprick autologous blood for dry eyes and persistent epithelial defects. Eye 2016;30:635-636.

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  6. Comment on: Eye hazards of laser 'pointers' in perspective

    Dear Editor I would like to thank the authors for their recent editorial "Eye hazards of laser 'pointers' in perspective" and that I agree and support the majority of points raised within the article. However I would like to correct one assertion made regarding the pilot injury reported by my team, that was published as a case report in January 2016. I would like to clarify some facts; the laser illumination incident was witnessed by both the pilot (victim) and captain, in addition to being subject to a police investigation. The pilot recalls how a blue laser beam illuminated from the right side of the cockpit, the pilot was sat on the right side of the flight deck at an altitude of 1300 feet. He recalls looking towards the laser beam by tilting his head slightly towards the right side; with the beam directly entering his right eye. Obviously concerned about the risk of blindness and injury, the pilot self presented to his local eye casualty department. He suffered temporary flash blindness immediately after the 'laser illumination' event, which once resolved left a blind spot within the superonasal field of the right eye. This corresponded to a mild focal laser retinal injury that was just visible on ophthalmoscopy, but clearly evident on fundus autofluorescence and ocular coherence tomography. The pilot was no longer subjectively aware of any blindspot in his vision a few weeks later, with a 24-2 Humphrey visual field found to be within normal limits. The lesion was uniocular, with no evidence of any retinal lesion in the fellow eye, either clinically or on retinal imaging. The retinal lesion has been monitored longitudinally over the last 18 months with evidence of healing commensurate with a retinal laser injury. Recently, the sensitivity of retinal lesion has been tested more accurately using fundus controlled microperimetry, with stimuli presented on the affected area; with focal reduction in retinal sensitivity over the retinal burn, with preserved retinal sensitivity within surrounding retina. Suggesting had the angle been different, and the fovea had been involved it would have resulted in visual loss; and potentially the end of this pilot's career. I as a retinal specialist, given the history provided to me by the patient and clinical findings identified on examination, alongside retinal imaging and my personal experience of treating eyes with retinal laser: I can only come to a single conclusion that the retinal lesion on this pilot's right eye was the result of the laser injury. Possibly due to the use of ocular coherence tomography and fundus autofluorescence I have detected a laser injury at much lower levels compared to injuries used to demonstrate Maximum Permissible Exposure and the Nominal Ocular Hazard distance. I would ask the authors to provide an alternative explanation of what induced this focal retinal lesion in a healthy fundus of a young gentleman, with an entirely healthy fundus in the fellow left eye? References 1. Gosling DB, O'Hagan JB, Quhill FM. Blue Laser Induced Retinal Injury in a Commercial Pilot at 1300 ft. Aerosp Med Hum Perform. 2016 Jan;87(1):69-70. doi: 10.3357/AMHP.4411.2016.

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  7. Re:Comment on: Population-based assessment of vision-related quality of life in corneal disease: results from the CORE study

    Dear Editor, We appreciate the interest shown by Jagat Ram et al and their well advised comments on our paper titled, 'Population-based assessment of vision- related quality of life in corneal disease: results from the CORE study.'1 As per their observation on the number of controls studied under marital status (n=435) in Table 1, the typographical error has been corrected and the change has been highlighted and the edited section of Table 1 is shown below. Now, the number of controls adds up to 435.

    Table 1: Vision Function scores by socio-demographic factors in cases and controls*

    Marital Status

    Cases (n=435)

    Controls (n=435)

    General functioning scale

    Psycho-social impact scale

    Visual symptom scale

    n (%)

    n (%)

    Case

    Control

    Case

    Control

    Case

    Control

    Married

    303 (69.7)

    403 (92.6)

    26 (22-32)

    P = 0.001#

    22 (21-25)

    P = 0.5

    6 (5-10)

    P = 0.001#

    5 (5-6)

    P = 0.7

    13 (9-21)

    P = 0.001#

    9 (7-13)

    P = 0.7

    Unmarried/

    132 (30.3)

    32 (7.4)

    34 (26-58)

    23 (21-25)

    8 (6-15.5)

    5 (5-6)

    17 (11-28)

    9 (8-13.5)

    Widow/ Widower

    Total

    -

    -

    28 (23-39)

    22 (21-25)

    6 (5-12)

    5 (5-6)

    14 (9-23)

    9 (7-13)

    *Data presented as Median (p25 p75) of VFQ scores

    #Statistically significant difference between groups

    We agree with the second comment raised by the authors that bilateral corneal conditions affect VR-QoL to a greater level than unilateral corneal conditions, but the authors miss a mark here by not taking visual impairment into account. The results presented in our paper are a part of a well planned population-based epidemiological study and we cannot question the results on clinical beliefs. As shown in our paper, visual impairment (based on visual acuity in both eyes) due to corneal disease affects VR-QoL significantly. Moreover, a point to note, is that VR-QoL is dependent on visual acuity and not on ocular involvement. Bilateral corneal conditions like pterygium and paracentral opacities with mild or no visual impairment, do not affect VR-QoL to a greater degree than a unilateral, total corneal opacity due to bullous keratopathy or trauma. Hence, bilateral corneal involvement may have more effect on the quality of life as compared to unilateral cases, considering visual impairment is similar in both sub-groups. Activities of daily living, as well as the ability to drive vehicles would be affected more in bilateral cases with significant visual impairment.

    The third point the authors raise is the variance of quality of life with the grade of corneal opacity. The grade of corneal opacity in the present study was graded as per the type (nebular, macular, leucoma), location, size and depth of involvement. A total of 571 eyes of 435 patients were detected with corneal opacity. For the purpose of analysis, the corneal opacity was divided into three grades ranging from mild to severe. As the VFQ scores were recorded per person and the corneal opacity was recorded eyewise, some cases had to be excluded from analysis. All unilateral cases and bilateral cases with same grade of corneal opacity in both eyes were used to compute VFQ scores in different grades of corneal opacity. Forty cases with dissimilar grade of corneal opacity in two eyes were excluded. The table below shows the variance of VR-QoL with grade of corneal opacity and demonstrates that VR-QoL varies significantly in the first two domains of vision function.? Table 2: Vision Function scores by grade of corneal opacity in the study population (n=395)*

    Type of Corneal Opacity

    General functioning scale

    Psycho-social impact scale

    Visual symptom scale

    Mild (80)

    26(22-44)

    6(5-12)

    14(9-21)

    Moderate (185)

    27(23-34)

    6(5-9)

    13(9-21)

    Severe (130)

    29(23-40)

    7(6-13)

    14(11-25)

    P value

    0.003*

    0.042*

    0.143

    *Data presented as Median (p25 p75) of VFQ scores

    #statistically significant difference between groups

    Again, we would like to reiterate that the results presented in our paper are a part of a well planned population-based epidemiological study and demonstrate the findings in this rural population. It is possible that married population in our study had better quality of life as compared to unmarried or widows/widowers in contrast to other populations described in earlier reports. We further explored reasons for this observation and we found that the married population was younger (Mean age=57.5 vs 69.9 of unmarried/divorced population). Hence, age could play as a confounding factor in this association.

    References: 1. Vashist P, Gupta N, Tandon R, Gupta SK, Dwivedi S, Mani K. Population- based assessment of vision-related quality of life in corneal disease: results from the CORE study. Br J Ophthalmol. 2016 May;100(5):588-93.

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  8. Re:The role of enhanced depth imaging optical coherence tomography in chronic Vogt-Koyanagi-Harada disease

    Dear Editor,

    We thank Uzun and Pehlivan for their interest in our article1 and their comments. They raise various factors that are potential confounders of subfoveal choroidal thickness measurements. As our study was a retrospective review of paired samples of enhanced depth imaging optical coherence tomography (EDI-OCT) and indocyanine green angiography (ICGA) in the right eye of patients with chronic Vogt-Koyanagi-Harada disease (VKH), we were unable to control for these factors. We recognize the limitations of a retrospective study and thus we advocated longitudinal studies to derive a more precise correlation between EDI-OCT and ICGA grade and hence its utility in monitoring chronic VKH.

    Soon-Phaik Chee and Aliza Jap

    References 1 Jap A. Chee S-P. The role of enhanced depth imaging optical coherence tomography in chronic Vogt-Koyanagi-Harada disease. Br J Ophthalmol 2016;0:1-4

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  9. Re:Comment on: Short-term choroidal thickness changes in patients treated with either ranibizumab or aflibercept: a comparative study

    Dear Editor,

    We would like to thank Dr. Uzun and Dr. Pehlivan for showing interest in our study.[1] It is well-known that various factors may influence choroidal thickness. In our study,[1] there was no significant difference in the age, sex, spherical equivalents, and incidence of diabetes mellitus and hypertension between the ranibizumab and aflibercept groups. As mentioned, the limitation of our retrospective study was that all potential influencing factors could not be perfectly controlled. Therefore, we agree with the opinion of Dr. Uzun and Dr. Pehlivan that these uncontrolled factors could influence the data obtained from our study. Dr. Uzun and Dr. Pehlivan particularly focused on the intraocular pressure (IOP) and diurnal variation on choroidal thickness. Unfortunately, the exact time of optical coherence tomography (OCT) scanning is normally not recorded in our institution. Thus, it is not possible to show whether the diurnal variation influenced our study result. In our institution, IOP is routinely measured during every visit using a pneumo-tonometer.

    To evaluate whether IOP significantly influences the study result, we reviewed the IOP values before and after the treatment. Since the primary outcome of our study was to compare the difference in changes in choroidal thickness between eyes treated with ranibizumab and aflibercept, the IOP values were compared between the ranibizumab and aflibercept group. In all the included eyes, the IOP at diagnosis and one month after the third intravitreal anti-vascular endothelial growth factor (VEGF) injection was 13.6 +/- 3.2 and 13.6 +/- 3.0, respectively. In typical neovascular AMD, the IOP at diagnosis and that after treatment in the ranibizumab group was 13.7 +/- 3.4 and 12.8 +/ - 2.8, respectively. The values in the aflibercept group were 14.0 +/- 3.0 and 13.9 +/- 3.1, respectively. There was no significant difference in the IOP at diagnosis (P = 0.571) and after treatment (P = 0.406) between the two groups. In polypoidal choroidal vasculopathy, the IOP at diagnosis and after treatment in the ranibizumab group was 13.8 +/- 3.3 and 14.1 +/- 3.1, respectively, while the values in the aflibercept group were 13.2 +/- 3.3 and 13.2 +/- 2.9, respectively. There was no significant difference in the IOP at diagnosis (P = 0.297) and after treatment (P = 0.374) between the two groups. In retinal angiomatous proliferation, the IOP values at diagnosis and after treatment in the ranibizumab group were 13.5 +/- 2.5 and 14.5 +/- 3.1, respectively, while those in the aflibercept group were 13.5 +/- 3.8 and 13.1 +/- 3.1, respectively. There was no significant difference in the IOP at diagnosis (P = 0.983) and after treatment (P = 0.194) between the two groups. Although the matter is controversial,[2,3] several studies have shown that there is an association between IOP and subfoveal choroidal thickness.[4,5] The result of the additional analysis on IOP shows that IOP may not significantly influence the result of our study. We hope further studies with a more controlled design may better elucidate the difference in the changes in choroidal thickness after injection of different anti-VEGF agents.

    REFERENCES

    1.Kim JH, Lee TG, Chang YS, et al. Short-term choroidal thickness changes in patients treated with either ranibizumab or aflibercept: a comparative study. Br J Ophthalmol 2016. doi: 10.1136/bjophthalmol-2015- 308074. [Epub ahead of print] 2.Pekel G, Acer S, Yagci R, et al. Relationship Between Subfoveal Choroidal Thickness, Ocular Pulse Amplitude, and Intraocular Pressure in Healthy Subjects. J Glaucoma 2016. doi: 10.1097/IJG.0000000000000401. [Epub ahead of print] 3.Wei WB, Xu L, Jonas JB, et al. Subfoveal choroidal thickness: the Beijing Eye Study. Ophthalmology 2013;120:175-80. 4.Wang YX, Jiang R, Ren XL, et al. Intraocular pressure elevation and choroidal thinning. Br J Ophthalmol 2016. doi: 10.1136/bjophthalmol-2015-308062. [Epub ahead of print] 5.Saeedi O, Pillar A, Jefferys J, et al. Change in choroidal thickness and axial length with change in intraocular pressure after trabeculectomy. Br J Ophthalmol 2014;98:976-9.

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  10. Comment on: Population-based assessment of vision-related quality of life in corneal disease: results from the CORE study

    eLetter Comment on: Population-based assessment of vision-related quality of life in corneal disease: results from the CORE study Parul Chawla Gupta, MS; Jagat Ram, MS, FAMS Department of Ophthalmology Post Graduate Institute of Medical Education and Research, Chandigarh, India, 160012 Corresponding author Dr. Jagat Ram, MS, FAMS Professor and Head Department of Ophthalmology Post Graduate Institute of Medical Education and Research, Chandigarh, India, 160012 Email id: drjagatram@gmail.com Conflict of interest and source of funding- None declared

    Dear Editor, We read with interest the recent paper by Vashist and associates [1] assessing the impact of corneal disease on vision-related quality of life (VR-QoL) in a rural North Indian population. We herein address important issues, some of which warrant further discussion. Firstly, as the authors stated "The Vision Related Quality of Life (VR-QoL) was assessed in 435 cases with corneal disease and 435 controls without any ophthalmic disease". However, in Table 1, under the subheading of 'marital status'; the total number of controls add upto 436. Secondly, in the present study, there was no statistically significant difference in VR-QoL scores between unilateral and bilateral corneal conditions. We strongly believe that patients with bilateral corneal involvement may have significantly more effect on the quality of life as compared to the unilateral [2] cases. Activities of daily living, as well as the ability to drive vehicles would be affected more in bilateral cases. Thirdly, no mention has been made of the variance of quality of life with the grade of corneal opacity. Lastly, an interesting observation in the present study was that in the cases with corneal disease, married patients had better scores on the IND-VFQ-33 questionnaire as compared to unmarried or widows/widowers in contrast to the study by Onakoya et al [3] carried out in glaucoma patients, in whom marital status had no significant effect on QoL scores. No competing interests References 1. Vashist P, Gupta N, Tandon R. Population-based assessment of vision- related quality of life in corneal disease: results from the CORE study. Br J Ophthalmol 2016;100:588-593. 2. Vu HTV, Keeffe JE, McCarty CA, Taylor HR. Impact of unilateral and bilateral vision loss on quality of life. Br J Ophthalmol 2005;89:360-363 3. Onakoya AO, Mbadugha CA, Aribaba OT, Ibidapo OO. Quality of life of primary open angle glaucoma patients in lagos, Nigeria: clinical and sociodemographic correlates. J Glaucoma. 2012;21(5):287-95.

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