eLetters

663 e-Letters

  • Cat scratch disease retintis on spectral domain optical coherence tomography

    Dear Editor,

    We have read the review article entitled “Ocular complications of cat scratch disease” Johnson A. Br J Ophthalmol 2020;0:1-7. We want to congratulate the author for this important review article, and make some contributions.

    In the review article, it has been indicated that optical coherence tomography (OCT) imaging is of value to monitoring cat scratch disease (CSD), particularly for neuroretinitis and multifocal retinitis.

    We would like to highlight a feature of focal retinitis with spectral domain optical coherence tomography (SD-OCT). Small areas of retinitis, less than 500 microns in diameter, can be seen on OCT imaging. These appear as areas of focal hyper-reflectivity of the inner retinal layers and decreased reflectivity causing a shadow on the outer retinal layers and choroid. This was seen in two patients presenting to our service recently with Bartonella henselae CSD diagnosed clinically and confirmed by positive serology.

    The first case was a 49-year-old Caucasian male who presented with bilateral inflammatory papillitis and multifocal retinitis without a macular star, confirmed with serology as Bartonella henselae (IgG >2048). He had good presenting Snellen visual acuities of 6/5 right, 6/6 left. OCT imaging at acute presentation showed multifocal retinitis seen as small areas retinal hyper-reflectivity of the inner retina with outer retinal disruption. The disease resolved without treatment in 8 months, with...

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  • Neoadjuvant Vismodegib plus Mohs Surgery for Locally Advanced Periocular Basal Cell Carcinoma

    Dear Editor,
    We read with great interest the excellent paper by Sagiv and collegues Ocular preservation with neoadjuvant Vismodegib in patients with locally advanced periocular basal cell carcinoma.1
    The article is a great contribution for a topic with a growing, but still limited worldwide experience. Our interest is to discuss the surgical approach after neoadjuvant Vismodegib.
    The authors present a patient with a 5x4cm locally advanced periocular basal cell carcinoma (LAP-BCC) with small nerve perineural invasion (>0.1mm) involving lower eyelid, inner canthus and cheek. The patient showed a significant response after 10 months of Vismodegib. Anyhow, it was clearly a partial response with 3 suspicious areas of BCC after treatment. The authors decided to treat separately each area with surgery, and histology (en face sections) confirmed the presence of tumor in two. The reconstructive outcome was excellent, and at the time of publication the patient was free of disease, 11 months after surgery.
    We agree with the authors, when they consider as a limitation the fact that “surgery did not always include the entire area of the original tumor”.
    Most studies involving smoothened inhibitors thus far have measured clinical tumor shrinkage but not true histologic margin control. Even after a complete clinical response (CCR), there is no way to assure that it will result in a complete histological clearance (CHR).
    Several authors discussed thi...

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  • Response to the e-letter to editor by Clemence et al on “The Central corneal basal cell density and nerve parameters in ocular surface disease and limbal stem cell deficiency: a review and meta-analysis”.

    To the Editor,

    We appreciate the authors' interest in our study. In their letter to the editor regarding our meta-analysis[1], the authors raise an issue regarding the inclusion of the diseases in the two groups i.e. limbal stem cell deficiency (LSCD) and ocular surface disease (OSD). We adhered to the categorization of the diseases as indicated or mentioned in the publications which were included in the meta-analysis. Our literature search based on combinations of various “key-words” or “key-terms” returned results as depicted in the categorization of the diseases in the study.[2,3] LSCD being a sub-set of OSD, has signs and symptoms in common with many other conditions, hence it was important that the term “limbal stem cell deficiency” appeared in the publications for the study participants to be categorized into the LSCD group.[2,3,4]

    The lack of consideration of the severity of LSCD and OSD was unavoidable due to the limited data within the source publications. It is apparent that the severity of the disease may affect the corneal epithelial basal cell density (BCD) and nerve fibre parameters.[5,6] The lack of data is likely explained by the difficulty in imaging in the more severe disease when corneal transparency is reduced; the corneal basal cells and nerves are difficult to image using confocal microscopy when the cornea is not clear. This is an important factor which is highlighted in our study.[1] Furthermore, our analysis did not attempt to c...

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  • Comments on “Long-term functional outcomes of different subtypes of primary congenital glaucoma”

    Dear Editor,

    We read the article published by Chaudhary, et al (1) with great interest and laud them on the quality and design of their study. Primary congenital blindness (PCG) poses a challenge to clinicians, both in terms of diagnosis, and treatment. (2)

    We would like to bring to the authors’ notice a similar study conducted in 2017 (3) of 230 eyes of 121 PCG patients having undergone a primary CTT. This study differed from the present study in the fact that it had a longer average follow-up period of 28.87 years with a more concentrated follow-up range of 21.5-38 years. There were also two main differences in the findings of the two studies.

    Contrary to the results in the present study where the infants with PCG fared better than the neonates (48.9% >6/60), the previous study found that 76.3% newborns with PCG had a vision better than 6/60. Additionally, the previous study, found visual acuity to be better than 6/60 in a greater proportion of patients (76.1%) at the last follow-up, as compared to the proportion in the study by Chaudhary et al (55.3%). Applying the WHO recommendation of measuring vision in the better eye, (4) the results improved to 89.3% in the study by Sood et al. (3)

    A possible reason for these disparities between the studies could be the difference in presentation times of the patients and the study inclusion criteria. While the present study reports late presentation, over half of the patients (53%) in the earlier pub...

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  • Keratoconus in Down syndrome: A diagnostic dilemma

    The recent study by Vega-Estrada et al highlights some of the challenges in diagnosing keratoconus in Down syndrome (DS).[1] Previous studies have shown that the cornea of individuals with DS without evidence of keratoconus appear to be steeper and thinner than the general population, both being features characteristic of keratoconus.[2] Vega-Estrada et al further identified that posterior keratometry was similar in DS to mild keratoconus, however, a lesser degree of posterior elevation was observed in the DS group.[1] This may be related to the younger mean age of the cohort with DS, small sample size or diagnostic criteria. The authors concluded that the corneal features analysed in the DS cohort were in the range of normal to mild keratoconus.[1]

    We would like to further highlight some of the challenges associated with image acquisition when performing corneal topo/tomography in patients with DS. Some of the ophthalmic manifestations such as slanted and small palpebral apertures, nystagmus and strabismus can affect fixation. We have also observed additional common behavioural responses that affect fixation and alignment; patients squeezing the eyes shut in response to the examiner touching the eyelids or involuntarily opening the mouth when asked to keep the eyes wide open.

    Misaligned fixation while acquiring corneal tomography images is known to result in false keratoconus features.[3] In addition to the reported overlap in corneal features in DS and ke...

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  • Repeatability of automated leakage quantification and microaneurysm identification ‎utilising an analysis platform for ultra-widefield fluorescein angiography. Avoid ‎misinterpretation

    Synopsis:‎
    Applying Pearson r to assesses the repeatability of a test is a methodologic mistake which leads to ‎misinterpretation.‎

    Repeatability of automated leakage quantification and microaneurysm identification ‎utilising an analysis platform for ultra-widefield fluorescein angiography. Avoid ‎misinterpretation
    Dear editor, We were interested to read the paper by Jiang A et al. published in Apr 2020 edition of the ‎Br J Ophthalmol.1 Ultra-wide field fluorescein angiography (UWFA) provides unique opportunities for ‎panretinal assessment of retinal diseases. The objective quantification of UWFA features is a labour-intensive ‎manual process, limiting its utility. The authors aimed to assesses the consistency/repeatability of an automated ‎assessment platform for the characterization of retinal vascular features, quantification of microaneurysms (MA) ‎and leakage foci in UWFA images. For each eye, two arteriovenous-phase images and two late-phase images ‎were selected. Automated assessment was performed for retinal vascular features, MA identification and ‎leakage segmentation. Panretinal and zonal assessment of metrics was performed. The authors mentioned a ‎significant correlation between paired time points for retinal vessel area and vessel length on early images ‎‎(Pearson r=0.92, p<0.0001; Pearson r=0.94, p<0.0001) and late images (Pearson r=0.92, p<0.0001; Pearson ‎r=0.92, p<0.0001, respectively). Panretinal and zonal MA counts demonst...

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  • Comment on Ocular manifestations of a hospitalised patient with confirmed 2019 novel coronavirus disease

    At the outset, we would like to congratulate the authors for determining the presence of the viral RNA over time in conjunctival specimens of a patient with COVID-19, which was much needed.
    The clinical course of viral conjunctivitis is self-limiting. Usually only supportive treatments like cold compress, artificial tears and topical steroids are given. The time duration taken for symptoms to subside without treatment ranges from 4-6 days to 2-3 weeks, depending upon the type of disease.[1] Clinical studies regarding the usage of antivirals for conjunctivitis reveal that they were effective only for DNA viruses and was not free of toxicity.[2]
    In the case report regarding ocular manifestation of patient with 2019 novel corona virus disease,[3] the ocular symptoms of patient resolved after 5 days of its onset and the author claims it to be possibly due to treatment with ribavirin eye drops. As Corona virus is a RNA virus, we believe that antiviral therapy would have been limited use. Adequate corneal tissue levels of antiviral agents are achieved by both topical and systemic administration.[4] If antiviral therapy was the reason for improvement of ocular symptoms, the patient was on three oral antiviral drugs (Umifenovir, lopinavir and ritonavir) in addition to topical ribavirin. Therefore, attributing only topical ribavirin for curing ocular symptoms may not be appropriate with the limited evidence.
    The authors also had mentioned that sterile synthetic f...

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  • Letter to the Editor

    To the Editor,
    We read with great interest the article entitled “Central corneal basal cell density and nerve parameters in ocular surface disease and limbal stem cell deficiency: a review and meta-analysis”. In the analysis, the authors found a similar reduction of basal cell density (BCD) and corneal nerve parameters between the limbal stem cell deficiency (LSCD) group and the ocular surface disorders (OSD) group. However, several missteps in the study methods occurred.
    First, the analysis included ocular diseases that could lead to LSCD in the OSD group (eg, severe and chronic vernal and atopic keratoconjunctivitis, bullous keratopathy, and ocular graft-versus-host disease).[1] Second, acute microbial infectious keratitis, which is generally not considered as an OSD because of its distinct pathology, was included in the OSD group. Third, the severity of LSCD and OSD was not considered in the analysis. As previously demonstrated, the decrease in BCD and basal nerve density is positively correlated with LSCD severity.[2 3] Fourth, the overall sample size was very small. Lastly, no sensitivity/meta-regression analysis was done despite the significant heterogeneity in the OSD group.
    We repeated the analysis after removing 7 studies wrongly included into the OSD group (Al-Aqaba &al, Leonardi &al, Muller &al -2 reports-, Moein &al, Cavalcanti &al, Tepelus &al) and not including them in the LSCD group because of heterogeneity of the st...

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  • Optic nerve hypoplasia is associated with neurodevelopmental abnormalities requiring neuroimaging and paediatric review for improved diagnosis

    This is an informative article highlighting the difficulties in diagnosing optic nerve hypoplasia (ONH) in infants. Comparisons were made of the reliability of MRI orbit to that of fundal photography, with the authors concluding that the latter was superior to neuroimaging for diagnostic purposes. Whilst valid, this may imply that MRI brain scans are not indicated when a diagnosis of ONH is under consideration.

    ONH has an incidence of between 2-10.9 per 100,000 births, systemic associations include developmental delay and neurologic deficits in over 50% and endocrine dysfunction in just over one-quarter of patients.(1) Children may display midline structural defects (abnormalities of the septum pellucidum, corpus callosum and pituitary axis), in addition to other cortical abnormalities, thus requiring neuroimaging.(1,2) A diagnosis of septo-optic dysplasia becomes appropriate when two out of three features are present: ONH, midline abnormalities and pituitary insufficiency. As babies and infants with ONH present primarily with abnormal visual behaviour, nystagmus, strabismus or amblyopia, from as early as 3 months of age, the Ophthalmologist may be the first specialist to evaluate the patient, and so the importance of investigating the wider clinical and radiological features cannot be overstated. This was not mentioned in this paper by Kruglyakova et al.

    Whilst one can argue that a normal MRI brain scan in a child with ONH is not predictive of future end...

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  • Comment on: Detecting optic nerve head swelling on ultrasound and optical coherence tomography in children and young people.

    Optic disc drusen pose a diagnostic challenge when trying to differentiate between papilloedema and pseudopapilloedema.1 Dahlman-Noor et al highlight the importance of a structured history when evaluating children with optic nerve head (ONH) swelling. The authors recommend a future study to explore the diagnostic accuracy of an algorithm published by the Royal College of Paediatrics and Child Health (RCPCH) which details key features of the history (e.g. headache, vomiting, visual symptoms) that should trigger neuroimaging.2

    As part of a prospective study of children referred to our regional paediatric ophthalmology service for assessment for ONH swelling, we implemented this algorithm. 122 children under 16 years of age were assessed from 1st January to 31st December 2018. 93% (113/122) had optic disc drusen, 4% (5/122) had normal optic discs, and 3% (4/122) had papilloedema. Two cases of papilloedema were caused by idiopathic intracranial hypertension (IIH) and two by venous sinus thrombosis.

    Of the 118 patients with drusen or normal discs, only one fulfilled the RCPCH criteria for neuroimaging: a 14-year-old girl with persistent headaches and vomiting. Neuroimaging and lumbar puncture were unremarkable, and her symptoms were ultimately attributed to migraine.

    For the four patients with papilloedema, the algorithm-derived questions would have triggered neuroimaging in three cases. This yields a specificity of 99% but a sensitivity of only...

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