Recent eLetters

We thank Dr Shoaib for his comments. In the results we clearly state 'The indication for insertion was based on the presence of ocular surface changes and poor tear film meniscus, with a previous unsuc- cessful management by lubrication and topical medication alone. Overall, 18 of the 25 patients had a concurrent systemic disorder (table 1).' Schirmer's test is , we believe , a poor test for dry eye in children. It often results in reflex tearing and is of little clinical value in children. Tear break up time is only of value if we know what the normal value is in CHILDREN. This is in fact the subject of our next manuscript which is in review as I write this. In children under 12 years of age and over 4 years of age , the non-invasive tear break up time using the Tearscope ( Keeler , Windsor ,UK) is over 25 seconds ( unpublished data as yet). So in children we looked at tear meniscus and ocular surface changes such as PEE. We not only relied on subjective improvement but also objective signs of improvement of ocular surface changes. As for the comparison of cases of BKC, we can only comment on our own paper which Dr Shoaib cites(1) . Please note that the majority of the children in the 'Punctal Plug' manuscript had a systemic disorder which led to secondary lid and corneal changes. In the article cited regarding BKC (1) many of the children had neovascularisation of the cornea and lubrication is clearly mentioned but not punctual plugs. We clearly state here in the 'Punctal Plug' article that children who failed lubrication were offered plugs. None of the cohort from the 2007 manuscript were in this manuscript. Finally, it is precisely because children can be so difficult to assess that there has been no previous manuscript, to the best of our knowledge, discussing punctual plugs exclusively in children.

1 Jones SM, Weinstein JM, Cumberland P, Klein N, Nischal KK. Visual Outcome and Corneal Changes in Children with Chronic Blepharokeratoconjunctivitis. Ophthalmology 2007;114:2271-2280

Conflict of Interest:

None declared

We welcome the latest estimates of global visual impairment (VI). (1) Posterior segment eye diseases (PSED): Glaucoma; Age-Related Macular Degeneration (ARMD); and Diabetic Retinopathy (DR) are now recognised as a major cause of VI worldwide and are more prevalent than infectious causes of VI such as trachoma and corneal ulcers. The majority of data collated in the last ten years from which these figures are estimated likely underestimate the true prevalence of PSED for three reasons: (a) The majority of surveys used the WHO coding instructions, which use the "principal disorder responsible for visual loss in the individual after considering disorders in either eye which are most amenable to treatment or prevention"(2), i.e. if a patient has co-existent PSED with cataract it will be deemed that cataract is the primary cause of VI. Therefore most VI prevalence data available in which cataract is the primary cause will underestimate the actual prevalence of PSED; (b) The Rapid Assessment of Avoidable Blindness (RAAB) methodology, which forms one of the most employed methods of gathering VI data in the last ten years (20 published from Africa, Latin America and Asia) does not allow for accurate diagnosis of PSED or differentiation between PSED; and (c) VI surveys have been designed to diagnose the cause of disease in those with varying degrees of visual impairment (?6/18 Snellen acuity) and thus pre-visually impairing disease is not detected. This is particularly important in the detection of PSED where cessation rather than cure is currently our only realistic management option. If VISION 2020: The Right to Sight's aims of alleviating suffering from avoidable blindness is to be met, the growing impact of PSED needs to be a focus of policy makers.

Conflict of Interest:

None declared

Article "Endothelial keratoplasty without Descemet's stripping in eyes with previous penetrating corneal transplants" by Nottage JM and Nirankari VS1, is very informative and the authors deserve appreciation for their wonderful work. However one point requires discussion. Authors mentioned that endothelial keratoplasty (EK) was done either for graft rejection (n = 9) or endothelial failure (n = 24). It seems logical to replace endothelium in endothelium failure. The question is how new endothelium can correct graft rejection? Authors mention "An allograft rejection was defined as corneal clouding in association with an epithelial or endothelial rejection line, keratic precipitates and/or anterior chamber cells." Endothelial line reflecting endothelial rejection can qualify as an indication for EK but the rest of the signs can be due to rejection of the other parts of the graft. A further breakdown of the frequency of above mentioned signs of allograft rejection would have been useful. Other authors have been careful not to include the generalized graft rejection cases for EK e.g. Chen ES et al2 mentioned in their Protocal under the heading of Methods, the inclusion criteria "after penetrating keratoplasty (PK) and without significant stromal haze". Similarly Straiko et al3 described inclusion criteria "for failed PK grafts from endothelial failure with minimal stromal Opacities" and "all eyes with a prior standard PK graft that had failed because of immunologic or nonimmunologic endothelial failure". Graft rejection results from host immunologic response against foreign antigen from donor tissue. Li JY et al 4 observed that it can lead to decreased endothelial cell survival and graft failure. They reported a graft rejection rate of 7.3 % and that the greatest number of rejections occurred between postoperative months 12 and 18. An initial improvement due to healthy endothelial can be expected in all cases of EK but antigenic stimulation will continue even after removal of the rejected graft's endothelium. Especially for the one patient regarding whom authors1 of the under discussion article wrote "had multiple previous graft failure, requiring placement of an investigational ciclosporine implant to prevent further rejection." Should we do EK or PK in PK rejection cases? Perhaps a longer follow up will answer this question. References: 1. Nottage JM, Nirankari VS. Endothelial keratoplasty without Descemet's stripping in eyes with previous penetrating corneal transplants. Br J Ophthalmol. 2012 Jan;96(1):24-7 2. Chen ES, Terry MA, Shamie N, Hoar KL, Phillips PM, Friend DJ. Endothelial keratoplasty: vision, endothelial survival, and complications in a comparative case series of fellows vs attending surgeons. Am J Ophthalmol. 2009 Jul;148(1):26-31.e2. Epub 2009 Apr 17. 3. Straiko MD, Terry MA, Shamie N. Descemet stripping automated endothelial keratoplasty under failed penetrating keratoplasty: a surgical strategy to minimize complications. Am J Ophthalmol. 2011 Feb;151(2):233- 7.e2. Epub 2010 Dec 3. 4. Li JY, Terry MA, Goshe J, Shamie N, Davis-Boozer D. Graft rejection after descemet's stripping automated endothelial keratoplasty graft survival and endothelial cell loss. Ophthalmology. 2012 Jan;119(1):90-4. Epub 2011 Nov 23.

Conflict of Interest:

None declared

A Mataftsi et al1 published an interesting article regarding punctal plugs in children. One of their aim was to establish the efficacy however they have not mentioned any test (Schirmer, Tear film break-up time, Rose Bengal staining, osmolarity) to confirm the diagnosis of dry eye and to calibrate the tear deficiency. It was only the clinical impression (flouresein staining is not specific for dry eyes and therefore cannot be used as diagnostic). In the follow up also, there was no yardstick to measure and compare the post procedure improvement with the pre procedure status. Only subjective feelings (patients or parents) are difficult to gauge and therefore a scientific test at this stage would have established the exact positive role of the plugs which could have been counterchecked and verified by other workers. These tests could have been done in the same sitting/ anesthesia and would not have required any additional visit or anaesthesia. A few points of this article differed markedly from previous articles. In "Blepharokeratoconjunctivitis in children: diagnosis and treatment"2 by M Viswalingam et al in which patients in Moorfields Eye Hospital, London, UK, were analyzed, there is no mention of dry eye in either the text or Table 1- Classification of the severity of blepharokeratoconjunctivitis (BKC) in children and Table - 3 Clinical symptoms and signs. Punctate erosions were present in only 9 % (all Asian) of their patients. Their patients improved without any dry eye treatment. Similarly in "Visual Outcome and Corneal Changes in Children with Chronic Blepharokeratoconjunctivitis"3 by Jones SM et al, in patients analyzed in Great Ormond Street Hospital for Children, London, UK, from1999 to 2005 (same hospital and almost same time period as is of the present article), there was no mention of dry eye and punctate epithelial erosions (PEE) were found in 31% of eyes. "In the authors' experience, effective treatment for BKC should include a combination of both systemic and topical antimicrobial therapy, along with topical steroids" was the authors' recommendation in the above mentioned article and no punctal plugs were mentioned. Now in the present article, authors have found a lot of dry eyes (out of which 14 required punctual plugs) in BKC (and PEE in 100%) among the almost same record which was used for the above mentioned article and now they claim "plugs were successful in treating a variety of causes of dry eye in our cohort, with more than half of the children presenting with lipid deficiency secondary to meibomian gland dysfunction".

Despite these observations, authors deserve appreciation for introducing the new concept of punctal plug use in children.

References: 1. Mataftsi A, Subbu RG, Jones S, Nischal KK. The use of punctal plugs in children. Br J Ophthalmol 2012;96:90-92. 2. Viswalingam M, Rauz S, Morlet N, Dart JK. Blepharokeratoconjunctivitis in children: diagnosis and treatment. Br J Ophthalmol. 2005 Apr;89(4):400- 3. 3. Jones SM, Weinstein JM, Cumberland P, Klein N, Nischal KK. Visual Outcome and Corneal Changes in Children with Chronic Blepharokeratoconjunctivitis. Ophthalmology 2007;114:2271-2280

Conflict of Interest:

None declared

We read with great interest the article by Mataftsi A et al.1 We congratulate the authors for providing insights into the use of punctal plugs in children. We would like to articulate a few of our observations. In seven cases where a secondary procedure was undertaken like a subconjunctival steroid injection or placement of contact lens, we believe these would be confounding factors in the final analysis even if we presume that this was a combination effect and not replacing one another? 30/64 (46.8%) of the plugs had spontaneous extrusion and these figures should have been highlighted in a clearer way. It would be of interest to know the additive effects of bipunctal versus monopunctal occlusion as well as the results of those who underwent a repeat punctal occlusion. We once again congratulate the authors for highlighting the beneficial effects of this therapeutic modality and for their commendable work.

Conflict of Interest:

None declared