Vernal keratoconjunctivitis and keratoconus

Pediatric keratoconus

Keratoconus is a common pediatric corneal disease, leading to vision impairment and amblyopia. Compared to its adult counterpart, pediatric keratoconus has an advanced presentation, rapid progression, higher incidence of complications such as corneal hydrops, and greater potential impact on the quality of life. It typically manifests during puberty and can evolve rapidly to more severe stages if left untreated. This rapid progression underscores the importance of early diagnosis through regular screening in pediatric populations and vigilant monitoring of pediatric keratoconus suspects. Concomitant ocular allergies, ocular anomalies, systemic diseases (e.g. syndromes), and poor compliance with contact lenses might impede prompt intervention and frequently postpone rehabilitation. Corneal collagen crosslinking is a crucial intervention in the management of pediatric keratoconus because it strengthens the corneal microstructure and halts the disease progression. When conservative measures fail, keratoplasty remains a viable option with generally favorable outcomes, though with unique challenges in post-operative care, including concerns related to sutures, long-term graft survival and need for repeated examinations under anesthesia. A multidisciplinary approach involving ophthalmologists, optometrists, pediatricians, and other healthcare professionals, focusing on early diagnosis and timely intervention, is essential for the comprehensive management of pediatric keratoconus and to mitigate its impact on children's lives.

Screening Preadolescents for Keratoconus Risk Factors in a Low-Resource Setting

BACKGROUND

Diagnosis of keratoconus (KC) involves the identification of corneal signs, refraction, and corneal imaging. The prevalence of KC ranges between 0.4 per 100,000 and 4,790, depending on geographical location and ethnicity. Diagnosis of KC should occur early for appropriate management with relatively affordable, accessible options to prevent visual impairment in low-income settings.

METHOD

Written consent and assent were obtained from subjects before a questionnaire was administered to collate demographics, general and ocular history of subjects, and keratoconus risk factors. A novel scoring system was applied to identify subjects at a higher risk of developing KC and document KC risk factors prevalent in Harare using an informed risk score calculation.

RESULTS

Thousand one hundred fifty-three subjects aged between 6 and 12 years were seen. The prevalence of KC was found to be 626/100,000 in primary school children resident in Harare. Reduced visual acuity, vernal keratoconjunctivitis, itchy eyes, eye rubbing, and atopy are the most prevalent KC risk factors identified in this community. Informed risk score calculation proved valuable in the screening for KC.

CONCLUSION

The prevalence of KC in primary school children in Harare is 626/100,000, which is relatively high. School-aged children stand to benefit from the early screening for KC based on evidence-based practices in the absence of advanced clinical instrumentation.

Keratoconus and inflammatory bowel disease: mendelian randomization

Background

Keratoconus is a diseased corneal dilation of unknown etiology. Studies have shown that inflammation may play a role in keratoconus. Inflammatory enteritis (IBD), including ulcerative colitis (UC), is a chronic, systemic inflammatory disease. We used Mendelian randomization to assess the causal relationship among IBD, UC and keratoconus.

Methods

The instrumental variable of IBD and UC was selected, the information of the instrumental variable in keratoconus outcome was extracted, and the causal relationship was assessed by the inverse variance weighted method by primary analysis, and its relevant sensitivity analysis.

Results

A causal relationship between IBD and keratoconus was observed significantly (P = 0.017, OR = 1.21, 95% CI = 1.03-1.41), and same as to UC and keratoconus (P = 0.038, OR = 1.25, 95% CI = 1.01-1.54).

Conclusion

IBD may play a causal role in the development of keratoconus, but the mechanism needs to be further elucidated.

Systemic and Ocular Associations of Keratoconus

Introduction

Keratoconus (KC) is the most prevalent corneal ectasia in the world and its pathogenesis is influenced by both ocular and systemic factors. This review explores the multifaceted associations between keratoconus and systemic health conditions, ocular characteristics, and various other environmental/exogenous factors, aiming to illuminate how these relationships influence the pathophysiology of the disease.

Areas Covered

This review will summarize the fundamental attributes of KC, review and discuss the systemic and ocular association of KC including molecular biomarkers, and provide an organized overview of the parallel alterations occurring within various biological pathways in KC.

Expert Opinion

Despite the substantial volume of research on keratoconus, the precise etiology of the disease remains elusive. Further studies are necessary to deepen our understanding of this intricate disorder and improve its management.

Tear Tacrolimus Levels and Clinical Response After Adjunct Therapy With Cutaneous Application of Tacrolimus 0.1% Over Upper Eyelid Skin in Chronic Vernal Keratoconjunctivitis

PURPOSE

The aim of this study was to evaluate the role of cutaneous application of 0.1% tacrolimus eye ointment over the skin of the upper eyelid in chronic vernal keratoconjunctivitis (VKC).

METHODS

A prospective, longitudinal, noncomparative, open-label clinical study of moderate-to-severe grade steroid-dependent VKC was performed. Study participants were initiated on adjunct therapy of cutaneous application of 0.1% tacrolimus ointment twice daily on the upper eyelid skin. Ocular surface evaluation parameters, meibomian gland imaging, intraocular pressure, visual acuity, and clinical disease severity scoring were performed to assess clinical response at baseline and month 3 of therapy. Tear levels of tacrolimus were measured at month 3 using high-performance liquid chromatography tandem mass spectrometry and correlated with the clinical score.

RESULTS

Palpebral form of VKC was observed in 85% of the cases, with positive family history in 5%, atopy in 7.5%, and keratoconus in 11.25%. Clinical assessment revealed improvement in 97.5% patients with discontinuation of concomitant topical steroids in 64% of patients. There were no changes in visual acuity, intraocular pressure, or ocular surface evaluation after therapy. Tacrolimus was detected in the tears of all our study patients after cutaneous application over the upper eyelid skin, proving its bioavailability with mean tear tacrolimus levels of 6.55 ± 21.43 ng/mL. Correlation analysis revealed a moderate negative correlation between the clinical score and tacrolimus concentration (Spearman correlation coefficient: -0.34, P = 0.002).

CONCLUSIONS

Cutaneous tacrolimus 0.1% ointment over the upper eyelid skin is an efficacious alternative method of application in treatment of VKC, with no resultant ocular irritation.

Estimated prevalence of keratoconus in the largest metropolitan area of Italy

PURPOSE

To estimate the prevalence of keratoconus in a population of subjects undergoing first eye examination in an eye clinic in Italy.

METHODS

A single-center, cross-sectional, study was conducted involving patients who underwent first eye examination at an eye clinic in Rome between September 2021 and June 2022. The prevalence of keratoconus was determined by Placido-disk corneal topography using the maximum keratometry (Kmax) value and the Cone Magnitude and Location Index (CLMI) for keratoconus screening. Subjective analysis was performed by two experienced corneal specialists, who classified the outcome into two groups: normal and keratoconus. Risk factors, including family history of keratoconus, allergy or atopy, thyroid disease, eye rubbing habit and gender were also examined.

RESULTS

A total of 512 subjects between 7 and 81 years old were evaluated. The inter-observer agreement to classify subjects in normal or keratoconus group was excellent (k = 1.0); the estimated prevalence in the specific population was 2.1%. Presence of positive family history (9% of keratoconus vs 5% normal), concomitant allergy or atopy (27% vs 9%) and eye rubbing habit (18% vs 4%) were associated with a higher risk of disease.

CONCLUSION

This study reported a high estimated prevalence of keratoconus in a metropolitan area of Italy, as found in recent studies in the Mediterranean and Middle East countries. Screening for keratoconus is highly recommendable and easily feasible with corneal topography under expert supervision and may be indicated primarily in young population to improve early detection and prompt therapeutic management for halting disease progression.

Current concepts in the management of cataract with keratoconus

This review analyzed all pertinent articles on keratoconus (KCN) and cataract surgery. It covers preoperative planning, intraoperative considerations, and postoperative management, with the aim of providing a simplified overview of treating such patients. Preoperatively, the use of corneal cross-linking, intrastromal corneal ring segments, and topo-guided corneal treatments can help stabilize the cornea and improve the accuracy of biometric measurements. It is important to consider the advantages and disadvantages of traditional techniques such as penetrating keratoplasty and deep anterior lamellar keratoplasty, as well as newer stromal augmentation techniques, to choose the most appropriate surgical approach. Obtaining reliable measurements can be difficult, especially in the advanced stages of the disease. The choice between toric and monofocal intraocular lenses (IOLs) should be carefully evaluated. Monofocal IOLs are a better choice in patients with advanced disease, and toric lenses can be used in mild and stable KCN. Intraoperatively, the use of a rigid gas permeable (RGP) lens can overcome the challenge of image distortion and loss of visual perspective. Postoperatively, patients may need updated RGP or scleral lenses to correct the corneal irregular astigmatism. A thorough preoperative planning is crucial for good surgical outcomes, and patients need to be informed regarding potential postoperative surprises. In conclusion, managing cataracts in KCN patients presents a range of challenges, and a comprehensive approach is essential to achieve favorable surgical outcomes.

[Current aspects of vernal and atopic keratoconjunctivitis]

BACKGROUND

Vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) are complex and rare diseases. Thus, their diagnosis and treatment are often a challenge.

OBJECTIVE

Discussion on the epidemiology, new pathogenetic concepts, interesting clinical findings, diagnostic possibilities and new treatment options and their side effects in severe ocular allergies. Analysis of the presentation of VKC in the internet.

MATERIAL AND METHODS

Evaluation of recent review articles, original publications, and case reports on the topics of VKC and AKC over the past 5 years.

RESULTS

Ocular allergies have significantly increased over the last decades. Recent concepts discussed in the pathogenesis of VKC and AKC are the role of the local and gut microbiome as well as the influence of neuroinflammation. Keratoconus is significantly more common in patients with VKC and AKC compared to the normal population. It is associated with faster progression and a more severe course of disease. A conjunctival provocation test is only rarely necessary in the diagnosis of allergic conjunctivitis. Treatment of atopic dermatitis with dupilumab, an interleukin 4 receptor alpha (IL-4Ra) antagonist, can cause ocular side effects. Unfortunately, information available on the internet for patients and parents on the topic of VKC is sometimes dangerously incorrect.

CONCLUSION

From the abovementioned new pathogenetic concepts, preventive and personalized treatment options could be developed in the future. Keratoconus in AKC/VKC must be recognized and treated early. Official guidelines are now available for a standardized conjunctival provocation test in the diagnosis of allergic conjunctivitis. The unwanted ocular side effects of dupilumab are often difficult to discriminate from the actual underlying AKC and respond well to anti-inflammatory treatment. Patients with VKC must be informed about the incorrect information on the internet regarding their disease.

Distribution and causes of blindness and severe visual impairment in children at a tertiary referral centre in Rwanda

AIM

To determine the prevalence and the causes of severe visual impairment and blindness (SVI/BL) in children at a tertiary referral centre in Rwanda.

METHODS

In this retrospective study, files of all patients <18 years presenting during the year 2019 at the Kabgayi Eye Unit in Rwanda with SVI/BL (presenting visual acuity of <6/60 Snellen or lack of preferential looking behaviour) in at least one eye were analysed for age, sex, laterality, province of origin and cause of SVI/BL. Causes were categorised according to WHO standard classification.

RESULTS

Out of 3939 children presenting to the clinic, 428 (10.9%) had SVI/BL in at least one eye. 165 (4.2%) patients had bilateral and 263 (6.7%) had unilateral condition. Of patients with BL/SVI, 36.7% were below the age of 6 years. In bilateral BL/SVI, the main causes were cataract (18%), refractive error (18%), keratoconus (13%), congenital eye anomaly (9%), glaucoma (8%), cortical blindness (8%) and retinoblastoma (6%). In unilateral BL/SVI it was trauma (46%), cataract (8%), keratoconus (8%), infectious corneal disease (7%) and retinoblastoma (7%). In preschool children, retinopathy of prematurity accounted for 7% of bilateral BL/SVI. Avoidable BL/SVI accounted for 87% of all cases.

CONCLUSION

The high number of avoidable causes for SVI/BL may be reduced through several cost-effective ways.

Long-Term Clinical Outcome of Tacrolimus Skin Ointment (0.03%) for the Treatment of Vernal Keratoconjunctivitis: A Quasi-Experimental Study

Background Vernal keratoconjunctivitis (VKC) is an allergic conjunctival inflammation with severe ocular complications if left untreated. The current management regimen is plagued with adverse effects, long-term problems, and clinical relapses. Tacrolimus offers an alternative treatment option, and long-term studies are needed to determine its efficacy. Methods A two-year follow-up based study was conducted on moderate to severe VKC patients, who were prescribed tacrolimus skin ointment. The 5-5-5 exacerbation scale was used for the monitoring and grading severity of the disease. Analysis of variance (ANOVA) and intergroup comparisons were conducted on exacerbation scale scores among follow-ups. Results A significant reduction was observed in the total score of severity from baseline (203.17±102.05) to three months' follow-up (69.94±70.54), and it kept reducing for 18 months post therapy. Similar results with statistically significant reduction were observed for all grades of the scale. The relapse rate was 5.71% within a month after therapy cessation, and none of the other patients showed relapse afterward. No significant ocular and systemic complications were observed during the study. Conclusion Tacrolimus is effective in the long-term management of VKC without the complications of conventional steroid-based therapy.

Subconjunctival injection of human umbilical cord mesenchymal stem cells alleviates experimental allergic conjunctivitis via regulating T cell response

BACKGROUND

T helper 2 (Th2) cells are thought to play critical roles in allergic conjunctivitis (AC). They release inflammatory cytokines to promote an allergic response in AC. Due to individual heterogeneity and long-term chronic management, current therapies do not always effectively control AC. Mesenchymal stem cells (MSCs) have been shown to be effective in treating allergy-related disorders, but it is unclear how exactly the Th2-mediated allergic response is attenuated. This study aims to elucidate the therapeutic effect and mechanism of the human umbilical cord MSCs (hUCMSCs) in a mouse model of experimental AC (EAC).

METHODS

A mouse EAC model was established by inoculating short ragweed (SRW) pollen. After the SRW pollen challenge, the mice received a single subconjunctival or tail vein injection of 2 × 106 hUCMSCs, or subconjunctival injection of hUCMSCs conditioned medium (hUCMSC-CM), and dexamethasone eye drops was used as positive control; subsequent scratching behavior and clinical symptoms were assessed. Immunostaining and flow cytometry were carried out to show allergic reactions and the activation of CD4 + T cell subsets in the conjunctiva and cervical lymph nodes (CLNs). Gene expression was determined by RNA-seq and further verified by qRT-PCR and Western blot. Co-culture assays were performed to explore the regulatory role of hUCMSCs in the differentiation of CD4 + naive T cells (Th0) into Th2 cells.

RESULTS

Subconjunctival administration of hUCMSCs resulted in fewer instances of scratching and lower inflammation scores in EAC mice compared to the tail vein delivery, hUCMSC-CM and control groups. Subconjunctival administration of hUCMSCs reduced the number of activated mast cells and infiltrated eosinophils in the conjunctiva, as well as decreased the number of Th2 cells in CLNs. After pretreatment with EAC mouse serum in vitro to mimic the in vivo milieu, hUCMSCs were able to inhibit the differentiation of Th0 into Th2 cells. Further evidence demonstrated that repression of Th2 cell differentiation by hUCMSCs is mediated by CRISPLD2 through downregulation of STAT6 phosphorylation. Additionally, hUMCSCs were able to promote the differentiation of Th0 cells into regulatory T cells in CLNs of EAC mice.

CONCLUSIONS

Subconjunctival injection of hUCMSCs suppressed the Th2-allergic response and alleviated clinical symptoms. This study provides not only a potential therapeutic target for the treatment of AC but also other T cell-mediated diseases.

Prevalence and clinical characteristics of vernal keratoconjunctivitis in sub-Saharan Africa

PURPOSE OF REVIEW

Vernal keratoconjunctivitis (VKC) is a chronic bilateral allergic inflammatory disease of the conjunctiva and cornea that affects children and young adults, especially in sub-Saharan Africa. A limbal form (tropical endemic limbo conjunctivitis) is thought to be more common in the tropics where research on this vision-impairing condition is scanty. We sought to review current literature from sub-Saharan Africa, with a focus on the prevalence of VKC and its clinical presentation.

RECENT FINDINGS

There is a variable prevalence of VKC in SSA, up to 32.9% of children, especially in male individuals less than 5 years old, and has been diagnosed in a 4-month-old baby. Associated factors include exposure to dust, personal and family history of atopy, Vitamin D3 deficiency and HIV. The mixed form of VKC is the most frequent form seen and conjunctival pigmentation might be an early diagnostic sign.

SUMMARY

Childhood screening programs for VKC should be established to reduce the morbidity, decreased quality of life and school absenteeism that is seen in these patients. VKC-related research should be encouraged in this milieu to bring to light the particularities of VKC in SSA.

Vernal Keratoconjunctivitis: A Systematic Review

Vernal keratoconjunctivitis (VKC) is a chronic, bilateral corneal and conjunctival problem which typically presents in young individuals. VKC is characterized by itching, photophobia, white mucous discharge, lacrimation, foreign body sensation, and pain due to corneal involvement of shield ulcers. Vernal keratoconjunctivitis is categorized within ocular diseases. The diagnosis is clinical, as no sure biomarkers pathognomonic of the disease have yet been identified. The VKC therapy relies on different types of drugs, from antihistamines and topical steroids to cyclosporine or tacrolimus eye drops. In extremely rare cases, there is also the need for surgical treatment for the debridement of ulcers, as well as for advanced glaucoma and cataracts, caused by excessive prolonged use of steroid eye drops. We performed a systematic review of the literature, according to PRISMA guideline recommendations. We searched the PubMed database from January 2016 to June 2023. Search terms were Vernal, Vernal keratoconjunctivitis, and VKC. We initially identified 211 articles. After the screening process, 168 studies were eligible according to our criteria and were included in the review. In this study, we performed a systematic literature review to provide a comprehensive overview of currently available diagnostic methods, management of VKC, and its treatments.

Outcome indicators for cross linking in pediatric keratoconus

Purpose

To evaluate the predictive factors for successful corneal collagen cross-linking (CXL) in pediatric patients with Keratoconus (KC).

Methods

This retrospective study was conducted using a prospectively built database. Patients (18 years old or younger) underwent CXL for KC between 2007 and 2017, with a 1-year follow-up period or longer. The outcomes included changes in Kmax (delta [Δ] Kmax = Kmax_last - Kmax_pre) and LogMAR visual acuity (ΔLogMAR = LogMAR_last - LogMAR_pre).The effects of CXL type (accelerated or non-accelerated), demographics (age, sex, background of ocular allergy, ethnicity), preoperative LogMAR visual acuity, maximal corneal power (Kmax), pachymetry (CCT_pre), refractive cylinder, and follow-up (FU) time on the outcomes were analyzed.

Results

One hundred thirty-one eyes of 110 children were included (mean age, 16 ± 2 years; range, 10-18 years). Kmax and LogMAR improved from baseline to last visit: from 53.81 D ± 6.39 D to 52.31 D ± 6.06 D (p < 0.001) and from 0.27 ± 0.23 LogMAR units to 0.23 ± 0.19 LogMAR units (p = 0.005), respectively. A negative ΔKmax (meaning corneal flattening) was associated with a long FU, low CCT_pre, high Kmax_pre, high LogMAR_pre, and non-accelerated CXL on univariate analysis. High Kmax_pre and non-accelerated CXL were associated with negative ΔKmax in the multivariate analysis.A negative ΔLogMAR (meaning vision improvement) was associated with a high LogMAR_pre in univariate analysis.

Conclusion

CXL is an effective treatment option in pediatric patients with KC. Our results showed that the non-accelerated treatment was more effective than the accelerated treatment. Corneas with advanced disease had a greater effect on CXL.

Novel Insights in the Management of Vernal Keratoconjunctivitis (VKC): European Expert Consensus Using a Modified Nominal Group Technique

INTRODUCTION

Vernal keratoconjunctivitis (VKC) is a rare, severe allergic ocular disease, typically occurring in children and adolescents, that can have a significant impact on quality of life and lead to visual impairment. Long-term treatment may be necessary to tackle chronic inflammation and topical corticosteroid dependency must be minimised due to the risk of complications. There is a need for unified clinical guidance to aid the assessment, diagnosis and management of VKC across Europe. The aim of this expert panel (the EUR-VKC Group) was to provide clear guidance for primary care physicians and general ophthalmologists involved in the diagnosis and management of VKC.

METHODS

An expert group of seven European ophthalmologists was convened and a modified nominal group technique used to develop key recommendations on VKC management. The recommendations were subject to up to two rounds of voting using a 5-point Likert scale to ascertain consensus and the strength of each recommendation. Consensus was set at a predetermined threshold of ≥ 75.0% of experts selecting 'Strongly agree' or 'Agree'.

RESULTS

A total of 47 recommendations were developed relating to the assessment of key of VKC, guidance on who and when to refer, as well as treatment-escalation pathways, long-term follow-up, and supportive care and education. All recommendations reached consensus after two rounds. The group emphasise how timely diagnosis and treatment initiation that is appropriate to disease severity are crucial to benefit patients with VKC. Patients with signs ('red flags') indicating severe VKC, or persistent mild-to-moderate VKC that is non-responsive following 2-4 weeks of treatment, should be referred to a sub-specialist.

CONCLUSION

The EUR-VKC Group provides recommendations on the assessment, diagnosis, management, referral and follow-up of patients with VKC. It also provides a framework to facilitate collaboration between primary care physicians, general ophthalmologists and sub-specialists to improve the outcomes for patients with VKC.

Vernal keratoconjunctivitis in Down syndrome: a case report

BACKGROUND

Down syndrome (DS) or Trisomy 21 is the most common chromosomal disease and is characterized by possible heart defects, cognitive impairment and visual disorders.

CASE PRESENTATION

We describe for the first time a 17-year-old Caucasian girl suffering from Down syndrome associated with vernal keratoconjunctivitis (VKC), a rare disorder of the anterior segment of the eye, characterized by intense photophobia, redness, watering eyes and itching due to an inflammatory-allergic reaction of the cornea and conjunctiva. On slit-lamp examination, the girl showed conjunctival hyperemia, papillary hypertrophy, giant papillae and corneal leukoma in right eye as a result of a previous corneal ulcer. A successful topical immunosuppressant therapy with cyclosporin 1% was started.

CONCLUSION

So far, to our knowledge, this is the first description of VKC in a patient with DS. Finding an inflammatory-allergic disease such as VKC in DS is unusual but it must be taken into account because keratoconus, one of the most frequent eye pathologies in DS, can be secondary to an unrecognized VKC.

Keratoconus in two siblings with congenital distichiasis

PURPOSE

To describe a previously unreported association of keratoconus in congenital distichiasis.

METHODS

Observational case series of ocular findings in 2 siblings with congenital distichiasis.

RESULTS

A 17-year-old male presented with tearing and photophobia in both eyes. His parents revealed that he was photophobic since birth. He had a lid surgery previously in both eyes. Clinical examination revealed a central scar with Descemet membrane tear suggestive of healed hydrops in the right eye. The left eye showed topographic features of keratoconus. His younger sibling, a 14-year-old female, also had similar symptoms of photophobia and tearing since birth. She had undergone electrolysis in both eyes. At the present visit, she had an epithelial defect with congestion in the right eye. Electrolysis of the distichiatic eyelashes was performed along with bandage contact lens application, which relieved her symptoms. Her topography revealed subclinical keratoconus in both eyes. The siblings' father also had complaints of photophobia since birth and had lid surgery and electrolysis in the second decade of his life.

CONCLUSIONS

Patients with congenital distichiasis may have associated keratoconus. Chronic ocular irritation and subsequent eye rubbing in distichiasis could be the risk factor for keratoconus.

Diagnosis and management of keratoconus by eye care practitioners in Kenya

BACKGROUND

To explore current eye care practice in keratoconus diagnosis and management in Kenya.

METHODS

An online questionnaire was distributed to ophthalmic clinical officers (OCO) and optometrists.

RESULTS

A total of 203 responses were received from 52 OCOs and 151 optometrists with a response rate of 24.4% and 53.5% respectively. The majority reported having access to retinoscopes (88.5%; p = 0.48) and slit lamps (76.7; p = 0.14). Few practitioners had access to a corneal topographer (13.5%; p = 0.08) and rigid contact lens (CL) fitting sets (OCOs 5.8%, optometrists 33.8%; p < 0.01). One-third did not feel that retinoscopy (38.7%; p = 0.21), slit lamp findings (30.3%; p = 0.10) and corneal topography (36.6%; p = 0.39) are important investigations in keratoconus diagnosis. Corneal topography was not recommended in two-thirds of patients (59.0%; p = 0.33) with vernal keratoconjunctivitis (VKC). The majority counselled against eye rubbing in mild (73.6%; p = 0.90) VKC, 52.9% in moderate (p = 0.40) and 43.6% in severe (p = 0.24) cases. The majority prescribed spectacles in mild (90.2%; p = 0.95), 29% (p = 0.97) in moderate and 1.9% (p = 0.05) in severe cases. When the binocular best corrected visual acuity (BCVA) with spectacles was ≤ 6/18, 76.9% of OCOs and 58.9% of optometrists referred for CLs (p = 0.02). When binocular BCVA with CLs dropped to ≤ 6/18, 83.7% (p = 0.18) referred to the ophthalmologist for surgical intervention. Few OCOs fitted rigid CLs (15.4% OCOs, 51.0% optometrists; p = 0.01), majority referred to optometrists (82.7% OCOs, 43.7% optometrists; p < 0.01). Progression was monitored in 70.1% (p = 0.11) of mild, 50.9% (p = 0.54) moderate and 25.3% (p = 0.31) advanced cases. Few OCOs (15.4%) performed corneal cross-linking (CXL). A few respondents (5.4%; p = 0.13) did not know when to refer keratoconus patients for CXL. Co-management with ophthalmologists was reported by 58.0% (p = 0.06) of respondents.

CONCLUSION

The results of this study highlight the need to map services for keratoconus patients, review current curricula and continuous education priorities for mid-level ophthalmic workers, develop guidelines for the diagnosis and management of keratoconus and improve interdisciplinary collaboration.

Penetrating Keratoplasty: Indications and Graft Survival by Geographic Region

Corneal transplantation, or penetrating keratoplasty (PK), is the most common form of solid-organ transplantation performed worldwide. Here, we evaluated the indications for PK and rates of transplant survival around the world by geographic region. We conducted a literature search of PubMed, MEDLINE, and Google Scholar databases and identified 155 relevant studies from 41 countries published between 1987 and 2021. The most common indications for PK were keratoconus in Europe, Africa, the Middle East, Australia, New Zealand, and Central and South America, bullous keratopathy in North America, and corneal scarring in Asia. The overall global mean graft survival rates at 1-, 2-, 3-, 5-, and 10-years were 88.6%, 81.2%, 78.9%, 72.8%, and 61.2%, respectively. Through this systematic analysis of PK by region, we hope to bring a new perspective to the corneal transplantation literature and to potentially highlight global differences and unmet needs in patient care.

Use of Corneal Topography in Pediatric Ophthalmology

AIM

To introduce the topic of pediatric keratoconus, highlighting the importance of routine corneal topography and tomography in children and adolescents from predisposed groups. To attempt to ensure the early detection of keratoconus and its subclinical form, enabling early treatment, which brings better expected postoperative results.  Material and methods: Using the corneal tomograph Pentacam AXL we examined children and adolescents with astigmatism equal or greater than  2 diopters (in at least one eye) and patients with at least one risk factor such as eye rubbing in the case of allergic pathologies, positive family history of keratoconus or certain forms of retinal dystrophy. In total, we included 231 eyes (116 patients), of which 54 were girls and 62 were boys.

RESULTS

The Belin-Ambrósio deviation index parameter was evaluated, in which we classified a total of 41 eyes as subclinical keratoconus and 12 eyes as clinical keratoconus. Next, the corneal maps were evaluated individually, in which we included a total of 15 eyes as subclinical keratoconus and 6 eyes as clinical keratoconus. In our group, compared to the control group, subclinical and clinical keratoconus occurred most often in the group of patients with astigmatism and in the group of so-called "eye rubbers". After individual evaluation, keratoconus occurred more frequently in boys than in girls in our cohort.

CONCLUSION

Most patients with keratoconus are diagnosed when there is a deterioration of visual acuity and changes on the anterior surface of  the cornea. Corneal topography and tomography allows us to monitor the initial changes on the posterior surface of the cornea, and helps us to detect the subclinical form of keratoconus and the possibility of its early treatment. Therefore, it is important to determine which groups are at risk and groups in which corneal topography and tomography should be performed routinely.

Combination Therapy of 0.1% Fluorometholone and 0.05% Azelastine in Eyes with Severe Allergic Conjunctival Diseases: A Randomized Controlled Trial

This study sought to evaluate the efficacy of the isolated use of fluorometholone compared with the combined use of azelastine and fluorometholone for the treatment of severe allergic conjunctival disease (ACD). One hundred and eleven patients with severe ACD were randomized into two groups: one treated with topical 0.1% fluorometholone combined with 0.05% azelastine and the other with 0.1% fluorometholone alone. The Ocular Surface Disease Index (OSDI) and the signs of keratopathy, palpebral conjunctiva papillae and conjunctival congestion were scored before and at one, two and six weeks after treatment and compared between the groups. The intra-ocular pressure (IOP) was also monitored. There were no significant differences between the groups in the baseline mean scores of signs and OSDI scores, which gradually improved at all visits after therapy in both groups. Although the time effect was significant for all the parameters (all p < 0.001), the reduction in corneal involvement scores from week 2 to week 6 was insignificant in both groups (p = 0.460 for the steroids group and p = 0.074 for the combination group). All signs and symptoms were significantly more improved in the combination group than in the isolated group at each control visit. IOP remained stable at all visits (all p < 0.001), except one patient in each group had elevated IOP over 21 mmHg. While both the isolated use of fluorometholone and combined use of azelastine and fluorometholone are effective in alleviating the signs and symptoms of severe ACD, optimal response can be achieved with adjunctive treatment including azelastine.

Altered retinal nerve fiber layer thickness in children with allergic conjunctivitis: the Nanjing eye study

Background

So far, few data are available on the relationship between allergic conjunctivitis (AC) and ocular fundus. Whether retinal parameters change in patients with AC remains unknown. In this study, we investigated the influence of AC on retinal thickness and vessel density among 7-years-old school-age children.

Methods

This large population-based study is part of the Nanjing Eye Study (NES). Comprehensive examinations including anthropometric parameters, refraction, ocular biometric parameters, intraocular pressure and retinal parameters were conducted on each child. Retinal thickness and vessel density were assessed using the optical coherence tomography angiography. Information on AC was obtained from a comprehensive questionnaire.

Results

A total of 739 children (mean age ± SD: 7.40 ± 0.29 years) had complete eye examination and questionnaire data we needed. Ninety-four children (12.7%) had AC, among which, 5 children had the history of corticosteroid use and were excluded from the final analysis. Spherical equivalent, axial length, body mass index and birth weight were correlated with retinal parameters. After adjusting for sex, age, spherical equivalent, axial length, body mass index, birth weight and premature history, children with AC had thinner retinal nerve fiber layer thickness for average (117.39 versus 120.97 μm, p = 0.007), temporal (80.73 versus 84.34 μm, p = 0.001), nasal (98.82 versus 102.18 μm, p = 0.049) and inferior (152.68 versus 157.06 μm, p = 0.034) quadrants than the control group.

Conclusions

Children with AC tended to have thinner retinal nerve fiber layer thickness. More attention is needed to fundus condition of children with AC.

Supplementary information

The online version contains supplementary material available at 10.1186/s12886-022-02399-7.