134 e-Letters

published between 2016 and 2019

  • Inclusion criteria and non-cycloplegyc examinations in study of refractive errors in Colombia

    We thank Dr. Tobon for his comments regarding our recently published article on refractive errors frequency in Colombia.1
    Initially he referred to the exclusion of the participants with less than 20/40 of distance corrected vision. The explanation of the application of this criterium was that, since as it has been shown, reproducibility of manifest refraction is less in patients with bad distance corrected visual acuity, and in this study we needed to have a very reliable manifest refraction examination.2
    However, we believe that Dr. Tobon highlights a very interesting point, which is worth analyzing in more detail. Ours and other studies that have analyzed the prevalence of refractive errors in a population have excluded eyes with other ocular conditions, including amblyopia. For example, in the study conducted in Mexico by Gomez-Salazar et al, which included a very large sample (more than 670,000 patients), they excluded patients with amblyopia.3 This made it impossible to analyze the frequency of amblyopia or anisometropia.
    In our study we excluded those patients with less than 20/40 of distance corrected visual acuity in any eye. Unfortunately, we did not keep the information on those patients excluded, and therefore we cannot determine the exact number or diagnosis of those cases. For future studies we will record such information.
    With regard to the second query of Dr. Tobon, we decided not to use cyclopegic refraction in this study, performed...

    Show More
  • Concerns about the inclusion criteria

    Best regards,

    I have read with great interest the article of Galvis et al about Prevalence of refractive errors in Colombia: MIOPUR study. It is a great effort and it might be the first study of its type in our country. In the discussion section, the inclusion criteria needs to be better explained.

    1: Why did they exclude the participants with less than 20/40 corrected vision?
    2: Is the vision exclusion criteria based on any eye or the better eye?
    3: Why didn’t they use cyclopegic medication for the refraction exam?

    These concerns affect the results because all of the amblyopic patients are excluded from the study and the hyperopic patients and those with an astigmatism that induce amblyopia are underreported, as seen in the table that shows a very low incidence in those refractive errors.

  • Tuning Of The Literature Related To The Airviscobubble (AVB) DALK Technique

    Tuning Of The Literature Related To The Airviscobubble (AVB) DALK Technique
    Corresponding author:
    Vincenzo Sarnicola
    Address: Clinica degli Occhi Sarnicola,
    Via Mazzini no. 62, Grosseto 58100, Italy.
    Fax: +39-0564-413023
    Tel: +39-3201158500
    e-mail address: v.sarnicola@hotmail.it or sarnicolavincenzo@gmail.com

    Vincenzo Sarnicola, MD1

    Enrica Sarnicola, MD1-3

    Caterina Sarnicola, MD 4

    1 Clinica degli Occhi Sarnicola, Grosseto, Italy
    2 Ospedale Oftalmico di Torino, Struttura Complessa Oculistica 2, Turin, Italy
    3 Ospedale San Giovanni Bosco, Struttura Complessa Oculistica 2, Turin, Italy
    4 Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, Italy;

    Competing interests: None.

    Keywords: DALK; airviscobubble; AVB; dDALK; descemetic DALK.

    Word Count: 303

    To the Editor:

    We read with interest the article published by Scorcia et al.[1] It is encouraging to see others, such as Scorcia et al, embracing the use of ophthalmic viscoelastic device (OVD) injection as a second bubble a...

    Show More
  • Collaterals or telangiectasias?

    I read with great interest the paper titled “Collateral vessels on optical coherence tomography (OCT) angiography in eyes with branch retinal vein occlusion (BRVO)” by Suzuki et al.1
    The authors defined collateral vessels as dilated and tortuous capillaries occurring in pre-existing capillary beds and linking the obstructed vessel with the nearest patent vessel, according to previous reports.2-4 The authors demonstrated that collaterals were detected in 23 out of 28 (82%) eyes, all of which already existed at mean 0.95 months after the onset, and that all of the collaterals were observed in both the retinal superficial and the deep layers.
    However, some of the vessels which are pointed out as collaterals in the study1 look like simply dilated/tortuous vessels, because they don’t seem to connect obstructed to non-obstructed adjacent vessels nor by-pass obstructions. In a previous report, the authors found collateral vessels in 18 out of 28 (64%) eyes at mean 25.1 months from the onset, while superficial and deep capillary telangiectasias were detected in 13 and 28 out of 28 eyes, respectively.4 Therefore, I suppose that some of the vessels defined as collaterals in this study1 may be simply telangiectasias.
    Fruend et al.5 defined collateral vessels as the authors did. After excluding collaterals involving the perifoveal vascular ring, they demonstrated that collaterals were found in 23 out of 23 eyes (100%) at median time of 3.79 years from RVO...

    Show More
  • Intraocular pressure change after injection of intravitreal dexamethasone (Ozurdex) implant

    I read with interest and appreciate the article by Choi et al 1 on 'Intraocular pressure change after injection of intravitreal dexamethasone (Ozurdex) implant in Korean patients'.
    As the study looks at the IOP changes after intravitreal dexamethasone implant, how the IOP was recorded for the patients is very important. The authors have reported that the intraocular pressure (IOP) was measured by non-contact tonometer (NCT) or Goldmann applanation tonometry (GAT) in this study. First, it is not mentioned as to which NCT was used for IOP measurement. If NCT was used to measure pre-injection IOP, was it used to measure post-injection IOP measurement also? Or on different visits IOP recording was done with NCT or GAT, is not clear. As GAT is still considered as a gold standard for IOP measurement, if IOP on NCT is found to be high, ideally it should be rechecked with GAT. Second, it is not mentioned whether a single IOP measurement was taken or multiple IOP measurements were obtained, taking the average value as the final IOP. Third, a s the lower range of age was 16 years (Table 1), was there any correlation of IOP change after the injection with the age?


    1. Choi W, Park SE, Kang HG et al. Intraocular pressure change after injection of intravitreal dexamethasone (Ozurdex) implant in Korean patients. Br J Ophthalmol 2018. Epub ahead
    of print. doi:10.1136/ bjophthalmol-2018-312958

  • Reply to: Comments on "Accuracy of trained rural ophthalmologists versus non-medical image graders in the diagnosis of diabetic retinopathy in rural China"

    Dear Editor,

    We thank Drs Sabherwal and Sood for their interest in our article.(1) We would like to respond to the interesting points they raise.

    Table 3 presents our analyses of potential predictors of the correct diagnosis by rural doctors of diabetic retinopathy (DR) requiring treatment. Details on a number of the characteristics assessed in this table are presented in the first paragraph of the Results section, but not, as Drs Sabherwal and Sood point out, the proportion having received didactic training. Among the 28 rural doctors, 13 (46.4%) received such training and 15 (53.6%) did not.

    In the Methods, we describe in detail the training received by ophthalmologists in the CREST (Comprehensive Rural Eye Service and Training) program. As described there, only two doctors per hospital (not all of whom examined patients in the current study) could attend the didactic phase of training at the Zhongshan Ophthalmic Center (ZOC). This is due to the limited number of ophthalmologists at a typical rural Chinese county hospital, and the heavy load of clinical duties. For more doctors to have left their facilities for the two-month didactic training would not have been practical. However, all ophthalmologists participating in the CREST network and in the current study received intensive hands-on training by medical retina experts from ZOC at their own facilities, which included the diagnosis and laser treatment of diabetic retinopathy (DR) as well as the u...

    Show More
  • Addendum

    Dear Editor,

    It has come to our attention that three of the patients (# 2 and #3, half-brothers, and #10) from our paper in BJO (1) have been reported previously with video recordings but without eye movement recordings at age 0 to 3 years in symposium proceedings (1) prior to the eye movement recordings made at age 6-11 presented in this study.

    Yours sincerely

    Irene Gottlob


    1) Pieh C, Simonsz-Toth B, Gottlob I. Nystagmus characteristics in congenital stationary night blindness (CSNB). Br J Ophthalmol 2008;92:236-240.

    2) Simonsz HJ, Gottlob I, Kommerell G, Hergersberg M, Eriksson AW: Transient Infantile Upgaze Holding Insufficiency: Frühsymptom bei inkompl. cong. stat. Nachtblindheit und periventrikulärer Leukomalazie. Der Ophthalmologe 1998;95(suppl 1/1):178.

  • Comments on: "Accuracy of trained rural ophthalmologists versus non-medical image graders in the diagnosis of diabetic retinopathy in rural China"

    Dear Editor,

    We read the article published by McKenna, et al (1) with great interest and laud them on the quality and design of their study. Screening for diabetic retinopathy in rural, low resource settings is the need of the hour, however models which are cost effective, yet provide intensive screening and continuum of care are limited. Keeping this in mind, we feel that there are a few points requiring further clarity in this article.

    The odds-ratio calculated in table 3 displays the significant effect of didactic training on correct diagnosis by rural doctors. However, for the odds-ratio to be calculated, there would have been a comparison group of rural doctors who were not provided didactic training. The numbers of these doctors have not been mentioned, and no details have been provided as to whether they were given any basic level of training related to the program. In the results provided for comparison between rural doctors and the non-medical graders, it has not been made clear whether doctors who had not been provided didactic training were included. In that case, results presented in the study may have been biased towards the non-medical graders.

    In the study, the arbitrator changed the grade for a high percentage of the cases, moreover, 33% of the images were not found to be of adequate quality. Hiring an arbitrator, re-checking the grading and assuring high quality images (2) through standard equipment and trained personnel would drive up...

    Show More
  • Response to Letter to the Editor

    To the editor and auther Kivela et al.:

    We thank the authors of the article “Intravitreal Methotrexate for Retinoblastoma” published in Ophthalmology in 2011 for their letter to the editor and adjustment of our discussion in our paper. As was found in your experience, as well as ours, intravitreal chemotherapy plays an important role in the treatment of retinoblastoma outside of its currently accepted use for intravitreal seeds. We look forward to hearing about your continued successful experience with intravitreal melphalan for use beyond intravitreal seeds.

  • Intravitreal chemotherapy in non-vitreal retinoblastoma

    In their report, entitled “Intravitreal chemotherapy in retinoblastoma: expanded use beyond intravitreal seeds“, Abramson and corkers report on the successful use of intravitreal chemotherapy in 52 patients for subretinal seeds and recurrent retinal tumours [1]. They state that, prior to their experience, intravitreal chemotherapy had been used exclusively to control persistent or recurrent vitreous seeding in retinoblastoma that had been refractory to systemic intravenous or intra-arterial chemotherapy.

    In fact, intravitreal chemotherapy as an adjuvant treatment for both subretinal seeds and recurrent retinal tumours, including its use instead of systemic chemotherapy in the setting of chemothermotherapy for small unresponsive primary retinoblastomas, has been in regular use already for a decade at the Ocular Oncology Service, Helsinki University Eye Hospital. Indeed, three of the first four patients that we reported during the congress of the International Society of Ocular Oncology in 2009 [2], and published in 2011 [3], received intravitreal methotrexate for reasons other than vitreous seeds. Subsequent experience with intravitreal chemotherapy with methotrexate and, later, with melphalan has strengthened our initial findings, as does the comprehensive report of Abramson and coworkers.

    1. Abramson DH, Ji X, Francis JH, et al. Intravitreal chemotherapy in retinoblastoma: expanded use beyond intravitreal seeds. Br J Ophthalmol 2018 Jun 6. pii: bjophthalmol-...

    Show More