134 e-Letters

published between 2016 and 2019

  • Dilemma of Ultra-low dose vs Low-dose Radiation Therapy for Ocular Adnexal Lymphomas: The prospective trial has been underway

    To the Editor:
    We herein respond to the letter written by Camus et al raising the issue of “ultra-low” dose radiation therapy (4 Gy) vs. the “standard low-dose” radiation therapy (24-30 Gy) for lymphomas of the orbit, eyelid, and conjunctiva, also referred to as “ocular adnexal lymphoma” (OAL). First off, it is important to point out that the goals of the retrospective multicenter general review of marginal zone lymphoma coordinated by Professor Steffen Heegaard in Denmark which also included some of our patients from M. D. Anderson was not to compare the efficacy of various treatment strategies.(1) Indeed it is challenging to draw practice altering conclusions from a retrospective multi-center study given the usual limitations, most notably the variation in staging and treatment approaches across various continents as noted by Camus et al.

    However, we agree with Camus et al that our encouraging preliminary observations in 22 patients with OAL treated with ultra-low dose radiation therapy (4Gy) suggested a very good response rate (100% ORR:86% CR, 14%% PR) for B-cell orbital and ocular adnexal lymphomas;(2) as such we started a prospective trial of ultra-low dose radiation for ocular adnexal lymphoma patients at MD Anderson Cancer Center soon thereafter (Clinicaltrials.gov identifier NCT02494700)The study aims to evaluate the efficacy of response adapted radiation therapy for this patient population, whereby all patients are treated to an initial 4 Gy in...

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  • Confounding effect of anterior chamber depth on assessment of dynamic air-puff applanation results in glaucoma patients

    We read the study by Vinciguerra et al. on cornea biomechanical properties of open angle glaucoma, ocular hypertension, normal tension and normal eyes assessed with dynamic air-puff applanation [1]. The study reported significant correlations between the properties and types of glaucoma. Most of the study patients were also under anti-glaucoma medication. Interestingly, the study did not assess the potential confounding effects of the anterior chamber on assessment of corneal biomechanical properties [1]. However, we wish to bring to the notice of the authors our earlier study on the same subject [2]. In our study, open and closed angle patients under the anti-glaucoma medication were assessed with air-puff applanation to determine if medication altered corneal biomechanical properties. The highlight of the study was that anterior chamber depth (ACD) was also included as a covariate in addition to other tomographic features [2]. Our study clearly showed that the ACD had a significant effect of the level of bIOP among the different types of glaucoma patient [2]. The ACD is a direct indicator of the volume of vault space between the cornea and the lens. This vault space resisted the inward motion of the cornea during the first half of the applanation. If ACD was lower, then bIOP was greater and vice versa. In patients with angle closure glaucoma, we expect the ACD to be less than NTG and normal eyes [1,2]. Hence, the results from the Vinciguerra et al. study could be skewed...

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  • Intraocular pressure change during reading or writing on smartphones in patients with normal-tension glaucoma

    The editor
    We would like to congratulate and highly appreciate Ha et al. for this simple and innovative study on ‘Changes in intraocular pressure during reading or writing on smartphones in patients with normal tension glaucoma’. However, we have few queries and seek your kind attention.
    First, out of 38 trabeculectomised eyes, 12 were not using any anti-glaucoma medications whereas remaining was on some antiglaucoma medications. An overall analysis was done including all trabeculectomised eyes. However, we think, it would have been better analyzed if the authors had compared eyes with or without antiglaucoma medications separately. We are interested to know the pattern of intraocular pressure (IOP) fluctuation in eyes with trabeculectomy not using any antiglaucoma medications.
    Second, in this present study, no control group was included.
    Third, it was established that there is circadian pattern of IOP change in normal tension glaucoma patients. Therefore, we are interested to know whether IOP was measured in all patients at the same time of day or was it measured at different times of the day.

    1. Ha A, Kim Y K, Kim J et al. Changes in intraocular pressure during reading or writing on smartphones in patients with normal-tension glaucoma. Br J Ophthalmol. 2019; Sep314467doi.org/10.1136/bjophthalmol-2019-314467
    2. Lee Y R, Kook M S, Joe S G et al. Circadian (24- hour) pattern of intraocular pressure and visual...

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  • Response to eLetter: The Estimated Number of Ophthalmologists Worldwide (International Council of Ophthalmology Update): Will We Meet the Needs?

    We appreciate the comment provided by Dr. Martins regarding our recent estimates of the global number of ophthalmologists, and we agree wholeheartedly with his points, which are encapsulate in the conclusion of our article.1 We appreciate the opportunity to further elaborate.
    Although the global ophthalmologist workforce appears to be continuously growing, our most important finding is that the numbers alone are not sufficient to ensure universal eye health coverage, with no relationship observed between national prevalence of blindness and ophthalmologist density.1 We believe the appropriate distribution, and deployment of ophthalmologist and eye care teams, combined with outreach services where appropriate are important solutions to increasing access of eye care among remote populations. However, we especially stress that the integration of comprehensive eye care into the health care system is critical to universal eye health coverage.2 We emphasize the need for different models of care and service-delivery and the role of the eye care professional cadres, including optometrists and allied ophthalmic personnel, particularly in task-shifting refraction and basic eye care services.
    Comprehensive eye care begins at the primary care level,2 and we agree that more ophthalmology education is needed as part of medical education. If primary care providers are able to provide basic eye care services at the community level, then it is assumed that task-shifting of the...

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  • Estimated number of ophthalmologists worldwide (International Council of Ophthalmology update): will we meet the needs?

    In the response to the article titled “Estimated number of ophthalmologists worldwide (International Council of Ophthalmology update): will we meet the needs?.” published in your esteemed journal, which is a well thought off and written paper, I would like to raise few points regarding this study.
    The article concluded that the estimated global ophthalmologist workforce appears to be growing, but, the appropriate distribution of the eye care workforce and the development of comprehensive eye care delivery systems are needed to ensure that eye care needs are universally met.1
    However, we can see that better population care requires more complex solutions than just increasing the number of ophthalmologists. Ophthalmologists need complex devices to perform diagnostics and surgery. That way, they end up in places with the necessary infrastructure for it. This problem does not affect the population of countries with good public transport infrastructure that allows people in small towns to access hospitals with ophthalmic care. However, this is not the reality of most of the world's population. In this way, other solutions must be considered.
    The teaching of ophthalmology in medical schools has been gradually reduced. The number of colleges in countries such as the United States, which have a compulsory formal internship in ophthalmology, has dropped from 68% in 2000 to 30% in 2004.2 Consequently, training has been ineffective in building basic knowledge i...

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  • Optometrists do not have to refer

    I read with interest the article by Kern et al: Implementation of a cloud-based referral platform in ophthalmology making telemedicine services a reality in eye care. I agree entirely that this is a way forward in ophthalmology, and increasing cooperation between optometrists and ophthalmologists is vital and in the best interests of the patient as well as the NHS.

    However, there is an important sentence in the introduction which is incorrect:

    'The Opticians Act 1989 obligates UK optometrists to refer any incidental eye abnormality detected during an NHS eye test to a Hospital Eye Services (HES) unless they provide a sufficient disease description including medical advice to the patient.7 '

    The obligation on an optometrist to refer a person who appears to be suffering from an injury or disease of the eye applied to any consultation, whether NHS or private. However, this was removed on 1 January 2000 when the General Optical Council’s Rules relating to Injury or Disease of the Eye (1999) came into force. Optometrists now have discretion as to whether or not to refer patients, and indeed many such patients are successfully managed in primary care as a result.

  • Authors' response: Three-year outcomes of small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for myopia and myopic astigmatism

    We thank Dr. Montserrat for the letter regarding our article “Three-year outcomes of small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for myopia and myopic astigmatism.”1
    Their first concern is that the predictability of the FS-LASIK group was 65% of eyes within ±0.5 diopter (D), which is also different from our experience. Of note, 95% of eyes were within ±1.25 D in the FS-LASIK group. This may be due to the long-term follow-up of 3 years leading to variability in the manifest refraction over time. In fact, our predictability results were similar to that of other long-term studies, as shown in Table 1.1-5 Moreover, it is likely a reflection of selection bias in our retrospective analysis i.e. patients with visual complaints were more willing to participate in the follow-up at 3 years – and we had acknowledged this as a limitation in our discussion. However, the probability of this bias may be the same for both surgical procedures and therefore did not significantly affect the final conclusion in our analysis.

    Table1 Summary of Long-term Predictability Results for LASIK
    Study Eyes (patients) Preoperative MRSE (D) Follow-up ± 0.50 of Emmetropia (%)
    Han T 41(41) −7.15±1.92 3 years 65
    Kobashi H 30(30) −3.81±1.40 2 years 73
    Alio JL 97(70) −7.15±1.92 10 years 49
    Zalentein WN 38(21) spere of -6.55±1.74 2 years 63
    O'Doherty M 94(49) −4.85±2.35 5 years 60

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    We have read with interest the article by Han et al.,1 in which the authors compare the outcomes of myopia correction using small incision lenticule extraction (SMILE) versus laser in situ keratomileusis (LASIK) using the VisuMax® femtosecond laser (FS) to cut the corneal flap, and we have some concerns regarding this study we would like to share with the authors.
    It is noteworthy that the authors found that only 65% of eyes were within ± 0.50 diopters of the attempted spherical equivalent correction after FS-LASIK, these results are clearly worse that those generally obtained with LASIK. It is accepted that the results obtained with excimer laser ablation, either using a surface ablation approach, or LASIK performed with mechanical microkeratome (MK) or using the Intralase® FS platform to correct myopia are quite similar.2,3 Indeed, our group has that 95% of unselected eyes with myopia of -3.9±1.5D3 and 80% of eyes with high myopia (-8.7±1.2D)4 were within ± 0.5D of emmetropia after LASIK. For this reason, we believe that the main conclusion of the article by Han et al.1 that “long-term outcomes of both SMILE and FS-LASIK are safe and equally effective for myopic and astigmatic correction” is clearly biased. In other words, the results of SMILE should have not been compared with a FS laser platform that does not seem to achieve the benchmark results clearly established for LASIK when correcting myopia.
    It should be highlighted that different FS platforms appr...

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  • Potential hazards of silicone oil released by the syringes

    Dear editor, we received with interest the comments by Wambier et al.1 They provided interestingly new insights in possible adverse effects of silicone oil on the human body. If enlarged lymph nodes and skin nodules assumed as sarcoidosis, and lumps in the abdomen of diabetic patients diagnosed as insulin fat hypertrophy are proved to be secondary to the silicone oil released by the syringes, a remarkable paradigm shift will be achieved. Incidentally, the idea of an inflammatory/immunological association to the presence of silicone oil droplets is in agreement with our yet unproven hypothesis that agitation of the syringe, silicone oil and a susceptible drug may cause non-infectious endophthalmitis after intravitreal injections.2
    However, we have to disagree with two other comments by the authors. Firstly, we employed two complementary techniques of assessing the presence of silicone oil from the syringes: light microscopy and Fourier-transform infrared spectroscopy.3-5 While the former allowed us to state that agitation of the syringe leads to a much higher release of silicone oil droplets with consistent and reproducible data, the latter showed that all models analysed have silicone oil in their interior, except for the oil-free one. Additionally, although it seems more reasonable, the use of a staining method might yield false-positivity, as we saw in our preliminary study.4
    Secondly, we believe that flushing the syringes with saline before drawing the drug...

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  • Reliability of Bruch’s membrane opening minimum rim width (BMO-MRW) and retinal nerve fibre layer thickness (RNFLT) with optical coherence tomography (OCT)

    Dear Editor,
    With great interest, we have read the article by Feihui et al.[1]
    This study has investigated the sensitivities and specificities of different diagnostic criteria based on the OCT for glaucoma detection. According to the article abnormal superotemporal and inferotemporal RNFLT attained a higher sensitivity than abnormal superotemporal and inferotemporal BMO-MRW to detect mild glaucoma. However, our query arises when “Integration of RNFLT / BMO-MRW assessment was done”. The author stated, integrating RNFLT and BMO-MRW assessment did not change the sensitivity and specificity of RNFLT but increased the sensitivity of BMO-MRW for detection of glaucoma. To quote the author, the author paradoxically stated “ Our finding underscores the importance of RNFL imaging and measurement in the diagnostic evaluation of glaucoma”. We are interested to know if sensitivity and specificity on combination is increased, why would the diagonostic performance not increased? Reis et al stated, Bruch's membrane opening minimum rim width (BMO‐MRW) reproducibility were comparable and excellent in both healthy subjects and patients with glaucoma to that of RNFLT measurements.[2]
    The article also did not include head tilt in the confounding covariates, as it was previously stated, head tilt significantly affects OCT image orientation as measured by the FoBMO angle.[3]
    The article has also not mentioned dimensions of the optic nerve head (ONH) as stated previo...

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