eLetters

137 e-Letters

published between 2017 and 2020

  • Honey eye drops, the effect of sugars

    I read the interesting manuscript entitled “Effect of a formulated eye drop with Leptospermum spp honey on tear film properties”. Authors have compared a formulated eye drop made of honey and regular lubricant drops finding some advantages of the honey eye drop. While the natural honey mainly composed of sugars, the beneficial effect might merely related to these simple carbohydrates. If authors have decided to find any effect, peculiarly attributed to the honey, they might design a control group with similar composition of simple carbohydrates to disclose the unclouded actual effect of the honey. On the other side, there might be some possible complications of promoting such agents as proved treatments, that have been already in use as alternative home made remedies; we have reported a case of Acanthamoeba keratitis using non-sterile honey eye drop (1).

    1. Peyman A, Pourazizi M, Peyman M, Kianersi F. Natural Honey-Induced Acanthamoeba keratitis. Middle East Afr J Ophthalmol. 2020 Jan 29;26(4):243-245. doi: 10.4103/meajo.MEAJO_56_18. PMID: 32153338; PMCID: PMC7034153.

  • Orbital MRI versus fundus photography and OPTOS in the diagnosis of optic nerve hypoplasia and prediction of vision

    Kruglyakova, et al recently published an excellent paper about visually pertinent correlation of optic nerve hypoplasia (ONH) with intra-operative photographic measurements1. We recently reported similar findings without subjecting children to general anesthesia if ultra-widefield imaging (OPTOS; Dunfermline, UK) is available2. We agree that a MD/DD ratio greater than 3.22 (≥3.51) is consistent with clinical optic nerve hypoplasia but our direct measure of horizontal optic nerve size was even more predictive utilizing our definition of logMAR for pediatric and low vision patients3. Instead of starting from the temporal edge of the optic nerve to determine MD (macula-disk) distance, we found the center of the optic nerve more uniform. In addition, we have also noted a worrisome relationship between ONH and threshold retinopathy of prematurity4 and wonder if the authors also found any association between the two common pediatric blinding conditions ONH and ROP?

    References:
    1. Kruglyakova J, Garcia-Filion P, Nelson M, Borchert M. Orbital MRI versus fundus photography in the diagnosis of optic nerve hypoplasia and prediction of vision. Br J Ophthalmol. 2020;104(10):1458-1461.
    2. Arnold AW, Eller AM, Smith KA, Grendahl RL, Winkle RK, Arnold RW. Direct nerve size determination and prevalent optic nerve hypoplasia in Alaska. Clin Ophthalmol. 2020;14:491—499.
    3. Arnold RW. Digital values for alpha acuities. JPOS. 2020:In Press.
    4. Arnold RW. Opti...

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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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  • 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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  • Response to the e-letter to editor by Bonnet 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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  • 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 discuss...

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  • RE : Chi et al : Selective Laser Trabeculoplasty Versus Medication for Open-Angle Glaucoma: Systematic Review and Meta-Analysis of Randomised Clinical Trials

    We read with great interest this comparison between selective laser trabeculoplasty (SLT) and medication for Open-Angle Glaucoma (OAG). (1)
    The recent LiGHT trial (2), an important landmark in the management of glaucoma, suggests that SLT represents an ideal first-line treatment option of ocular hypertension (OHT) and open angle glaucoma (OAG) in terms of decreased costs, with similar efficacy and quality of life when comparing to medication. The strength of the trial resides in its methodology, limiting most of the bias seen in the previous retrospective studies on the subject. Despite the fact that their conclusions seemed to be echoing various other authors (3,4) there is still debate as to whether SLT should become a first-line treatment.
    The current powerful meta-analysis by Chi et al on 1229 patients (14 articles, 8 randomized clinical trials), may become the final argument on the debate demonstrating that not only is SLT not inferior to medical therapy in terms of IOP-lowering effect or safety, but it allows for significantly lesser use of medication. (1)
    The longer duration of effect, minimized cost, and safety of SLT are especially important in settings with difficult access to care, such as in developing countries, or in patients with decreased mobility. A recent study on incarcerated patients showed that even when measures are taken to administer and control patients’ adherence to treatment, substantial nonadherence persists. (5)
    It is ri...

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  • Authors Response to Dr. Dhananjay Shukla's Correspondence

    We thank Dr. Shukla for his interest in our article and his comments 1, 2.
    In our study all consecutive cases of rhegmatogenous retinal detachment (RD) that underwent pars plana vitrectomy (PPV) were included in the study regardless of complexity, type of tear, lens or refractive status, or use of supplemental buckle in order to reduce selection bias and to allow study of various subgroups of patients. For the same reason the 13 cases with silicone oil present at the time of last follow-up were not excluded. The paper referenced by Dr. Shukla reports a retinal re-detachment rate of 13.2% after removal of silicone oil (ROSO), with many of the cases performed prior to the era of small gauge vitrectomy and wide-angle viewing systems (WAVS) 3. Encircling endolaser photocoagulation further reduces the re-detachment rate to 8.6% 4. More recent surgical techniques are likely associated with a lower retinal re-detachment rate. Nevertheless, a presumed retinal re-detachment of 13.2% following ROSO corresponds to an estimated 1.7 eyes with recurrent RD out of the 13 eyes with residual silicone oil in our series 3. This in turn corresponds to a 0.5% difference in the overall single surgery success rate (SSSR) in 312 eyes. It could therefore be safely assumed that inclusion of the small group with silicone oil at the last follow-up visit did not affect the overall success rate significantly, but reduced chances of introducing a selection bias.

    In our series a supplemental...

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  • Preoperative guttae screening of the donor corneas

    We read with great interest the article entitled ‘Prevalence of guttae in the graft following corneal transplantation’ by Nahum et al, published in the May 2015 issue of the British Journal of Ophthalmology [1] . The authors reported the prevalence of cornea guttata postkeratoplasty in a large population of 1116 patients to be 4%. They also found that guttae postkeratoplasty do not negatively affect the visual acuity, endothelial cell density, or graft survival during the initial two postoperative years. The content of this article is important and well put, since this is the first study to reveal the prevalence and sequelae of postkeratoplasty guttae on the corneal graft.

    Based on our clinical experience and on multiple published studies, the prevalence of cornea guttata in the normal population is estimated to be higher than 4% [2]. However, the low prevalence reached by Nahum et al, is explained mainly by the preoperative screening of the donor corneas for guttae, as stated in the article. Therefore, it would be very interesting if the authors can provide an estimation of the percentage of donor corneas that are usually discarded by the guttae screening in their eye bank.

    Up to our knowledge, guttae are very often not detectable using inverted light microscopy, thus guttae screening as a part of the routine examination of the donor corneas is a challenging task. There is only one study performed by Borderie et al in 2001 [3], that aimed to detect the pres...

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