[Amblyopia-Basic principles and current diagnostic and therapeutic standards]

Amblyopia is a visual deficit that occurs during childhood and results in an abnormal development of the normal cortical visual pathway. It is defined as the reduction of best corrected visual acuity of one or rarely both eyes, which is not explained by structural abnormalities of the eye alone. During the sensitive period amblyopia is completely or partially reversible. The main causes of amblyopia are strabismus and refractive errors. Congenital cataracts are less common but if present may cause pronounced amblyopia. In Germany the prevalence of Amblyopia is approximately 5%, which is relatively high in relation to other countries, even though data are not completely comparable. As amblyopia can only be successfully treated during the first years of life, early detection of amblyogenic factors is important. Screening tests help in identifying children at risk of amblyopia, while only a thorough ophthalmological examination including cycloplegic refraction reliably detects all risk factors of amblyopia. Treatment consists of removal of the amblyogenic factors and stimulation of the amblyopic eye.

[Emigration-an option for African resident physicians? : Opinions from Tanzania and Ethiopia]

BACKGROUND

Globally, the majority of visually impaired persons live in low- and middle-income countries. One of the reasons is a lack of ophthalmologists in the respective countries. Migration of qualified personnel would be an additional strain on ophthalmological patient care.

OBJECTIVE

This analysis aimed at evaluating the attitude of African residents in ophthalmology towards working in their home country or migrating abroad and comparing these findings with existing data also with respect to possible interventions.

MATERIAL AND METHODS

In 2016 and 2017, participants of ophthalmological training courses for residents in Dar es Salaam (Tanzania) and Addis Ababa (Ethiopia) as well as residents from Moshi (Tanzania) were interviewed on possible migration with the help of a questionnaire.

RESULTS

In total 60 questionnaires were analyzed. The main reasons for staying in the home country were: "want to support/serve community", "family" as well as "high demand of specialists". Prime motives for possible migration were: "better income", "better working structure/equipment" and "better education".

CONCLUSION

Links between German and African eye hospitals as they are supported, for example by the working group International Ophthalmology of the German Ophthalmological Society (DOG) and the German Committee for the Prevention of Blindness (DKVB), can contribute to improve some of the main reasons of migration, such as insufficient education, working structures and equipment and thus help to prevent a brain drain.

[German ophthalmology in developing countries : Partnerships with eye clinics in developing countries - an initiative of the German Ophthalmological Society]

In 1999 the global initiative "Vision 2020 - The Right to Sight" was established by the World Health Organization (WHO), the International Agency for the Prevention of Blindness (IAPB) and several non-governmental organizations (NGOs) with the goal of reducing avoidable blindness. Based on this initiative, the working group "International Ophthalmology" of the German Ophthalmological Society (DOG), which was established in 1994, was converted into a DOG section with the same name in 2004 and represents one of the core components of the DOG; however, even before there were a number of established partnerships of German and African eye hospitals. The first cooperation of this kind was the partnership between the Department of Ophthalmology, Ludwig-Maximilians University Munich and the University of Nairobi, Kenya, which was founded in 1978. As a result of this cooperation, the Department of Ophthalmology in Nairobi has evolved into one of the major centers of ophthalmological training and ophthalmic care in East Africa. Since then a number of similar cooperation projects between several hospitals and numerous further projects (e. g. in Myanmar) have been implemented and some of these are presented in this manuscript.

[Tropical ophthalmology : Intraocular inflammation caused by "new" infectious pathogens and travel-related infections]

A number of "new" (emerging) infections that can also cause inflammatory eye changes are appearing and becoming increasingly important. In the past, diseases such as chikungunya, dengue fever or West Nile virus infections were endemic in tropical regions, but are now expanding worldwide and causing significant morbidity and even mortality. "Globalization" and human migration are important factors leading to the import of these infections. Climate changes are probably even more important. Increasing temperatures provide suitable conditions for new vectors, and may lead to autochthonous transmission of infectious pathogens. Diagnosis of these diseases requires not only careful assessment of medical and travel history, but also the application of specific laboratory diagnostic tests. A broad spectrum of ocular involvement has been reported, with frequent posterior segment involvement. Emerging infections should therefore be considered in the differential diagnosis of retinitis, chorioretinitis, retinal vasculitis and optic neuropathy in a patient living in or traveling back from an endemic area. Since these infections are often vector (insect) borne and effective treatments are almost uniformly lacking, prevention is at least as important as prompt diagnosis and initiation of supportive care. Here, we focus on Chikungunya, Dengue fever, Ebola fever, the West Nile virus and Rickettsioses, which frequently demonstrate ocular involvement.

[International ophthalmology and travel medicine]

Medical eye care in developing countries is very different from the situation in industrialized nations. In order to prevent rising numbers of blind people worldwide due to increased life expectancy and population growth, the global initiative Vision 2020 "The Right to Sight" was established in 1999. Coordinated initiatives are important as most causes of blindness are either preventable or curable (e.g. cataract surgery); however, due to a lack of resources eye care in developing countries cannot implement all necessary preventive and therapeutic measures at present. The epidemiology of causes of blindness and the situation of ophthalmic care are discussed. Because of increased mobility of people and goods (e.g. air travel and trucking), imported eye diseases are of increasing importance. The difference between travel medicine, which deals with the medical situation of travelers and international ophthalmology (i.e. diseases in tropical countries) is discussed and illustrated on the basis of several important disease patterns.

[Optic Disk Drusen: Historical and Up-To-Date Aspects]

Optic disc drusen are an important differential diagnosis in the diagnostic evaluation of a prominent optic nerve head. Drusen of the optic disc occur in 0.34 to 2.4 % of human individuals and manifest themselves bilaterally in three of four cases. Drusen are found six times more often within histological sections than on funduscopic examination. It is known that optic disc drusen can occur in familial clusters without any other pathological ophthalmic findings. They can also be associated with retinitis pigmentosa, or with the Joubert or Alagille syndromes. Non-invasive diagnostic tools include fundus-autofluorescence (AF), optical coherence tomography (OCT) and ultrasound. Drusen of the optic nerve head are asymptomatic in most cases, though transient ischemia can lead to transient visual impairment. In particular, superficial drusen can lead to profound visual field defects in adulthood. Regular ophthalmological follow-up examinations with tonometry and perimetry are recommended for the early detection of visual field defects. Radial optic neurotomy (RON) seems to be a therapeutic option in patients with acute deterioration of the visual field.

[Retinoblastoma in Kenya: survival and prognostic factors]

BACKGROUND

In industrialized nations a curative therapy of retinoblastoma can be achieved in a large number of patients due to timely diagnosis and therapy. In developing countries the survival rates are much lower and very little data have been published especially from Africa.

OBJECTIVES

This study was performed to investigate the survival and prognostic factors of retinoblastoma patients admitted to Kenyatta National Hospital, the national referral hospital in Kenya.

MATERIAL AND METHODS

In this study all records of patients admitted with retinoblastoma from January 2000 to December 2004 were reviewed. Demographic data, clinical presentation, intraoperative findings and histology reports were recorded and the patients or their relatives were contacted during follow-up to investigate the outcome and survival.

RESULTS

Files of 160 patients (86 males and 74 females) were retrieved for this study. Data on 3-year survival could be acquired from 105 patients and the cumulative 3-year survival rate was 26.6 %. Factors significantly influencing survival were age at presentation less than 12 months, early disease at presentation (leukocoria only), no extraocular growth and total delay of management ≤ 5 months. Proptosis and tumor recurrence were associated with a 3-year mortality of 100 %.

CONCLUSION

The main reasons for poor outcome were late presentation and recurrent disease after initial treatment elsewhere, extraocular growth and delay between initial presentation and treatment. Awareness of the public and of healthcare workers should be increased in order to reduce the time delay until diagnosis and treatment.

[Genotype-phenotype correlation in patients with PRPH2-mutations]

BACKGROUND

The peripherin-2 (PRPH2) gene encodes a photoreceptor-specific transmembrane-protein called peripherin-2 which is critical for the formation and maintenance of rod and cone outer segments. Over 90 different disease-causing mutations in PRPH2 have been identified which cause a variety of forms of macular degeneration and also retinopathia pigmentosa.

PATIENTS/MATERIAL AND METHODS

This study is a retrospective observational study of 3 patients ascertained over a 5 month period in the ophthalmogenetic consultation of the university ophthalmic clinic. So far, the patients were followed for 8 months at least. Data examined included clinical history, pedigree analysis, ophthalmological examination, fundus photography, autofluorescence imaging, optical coherence tomography, Arden colour test, Goldmann perimetry and detailed electrophysiological assessment. Blood samples were taken for DNA extraction and mutation analysis of PRPH2 and ABCA4, BEST1, C1QTNF5, CDH3, CNGB3, ELOVL4, FSCN2, PROM1, RDH12, RP1L1, RPGR, TIMP3 was performed.

RESULTS

All patients had presented with clinically evident maculopathy and visual acuities in the range of 1/50 Metervisus to 0.8 p [dec.]. All had specific electroretinogrammes. All PRPH2 mutations were autosomal dominant. One family was heterozygous for a previously reported missense mutation in the PRPH2 gene c.514C>T, p.R172W. The other patient was heterozygous for a so far non-described PRPH2 deletion and frameshift mutation c.74_77delGGTT, p.W25SfsX12 leading most likely to a truncated, dysfunctional protein. All patients showed a significant, inter-individual phenotypical variability.

CONCLUSION

The data add to the documented phenotypical variability of PRPH2 mutations and describe the c.74_77delGGTT, p.W25SfsX12 mutation within PRPH2 for the first time. FAF, OCT and electrophysiological exams are helpful tools for diagnosis and evaluation of macular disease due to PRPH2 mutations.

[Staying and working at home or considering migrating: Survey-based study of African ophthalmologists]

BACKGROUND

The shortage of ophthalmologists is a major obstacle in the struggle of fighting preventable blindness in sub-Saharan Africa. However, to date reasons affecting migration of ophthalmologists have not been completely understood.

OBJECTIVES

Evaluation of reasons reported by ophthalmologists for staying in their current work setting/country, of potential reasons for migration as well as of effects of German-African partnerships.

MATERIAL AND METHODS

In the years 2009-2011 and 2013 participants of continuous medical education courses in Ethiopia, Cameroon and Kenya were interviewed using a standardized questionnaire.

RESULTS

A total of 106 ophthalmologists participated in this survey. In the years 2009/2010 participants were mainly board certified ophthalmologists, while the 2011/2013 surveys were answered mainly by residents. The main reasons for staying in their current region/country were good working conditions, commitment to help/patriotism, possibility of further training, good income and familial ties. Professional development elsewhere and better income abroad were named as the main reasons for considering migration followed by better technical equipment elsewhere and insecurity in the home country.

CONCLUSION

Good working conditions and the possibility of further training were named as the top reasons for staying in the current region/country apart from commitment to help and familial ties. Therefore, international cooperation programs aiming at improving training of ophthalmologists and establishing an ophthalmic infrastructure may have a role in promoting ophthalmic care in Africa.

[Hepatic metastases in CUP (cancer of unknown primary) and painful amaurosis]

A 63-year-old woman presented with a 9-month history of painful amaurosis of the left eye caused by hemophthalmos. She was already undergoing chemotherapy for histopathologically proven liver metastases caused by an assumed melanoma. The location of the primary tumor was unknown. Whole-body FDG-PET/CT staging identified a lesion with characteristically malignant uptake in the region of the left eye as the primary tumor. After enucleation, a primary uveal melanoma was verified that expressed the serological marker melanoma inhibitory activity (MIA). FDG-PET/CT was able to successfully align hepatic metastases due to CUP with local ophthalmologic diagnostic findings and led to a correct diagnosis.

[Chronic endogenous endophthalmitis]

An endogenous endophthalmitis is a severe, potentially blinding intraocular infection due to haematogenous spread of germs. In Europe, gram-positive bacteria and Candida albicans are common causative organisms. Compared to post-operative cases of endophthalmitis, endogenous endophthalmitis is relatively rare, accounting for 2-8% of all endophthalmitis cases. Most patients suffer from an underlying disease causing some kind of immunodeficiency. Other predisposing factors are long-term therapy in intensive-care units (ICU), intravenous catheters, iatrogenic immunosuppression or intravenous drug abuse. Final visual acuity strongly depends on the time needed for the correct diagnosis, the infectious agent and the selection of adequate treatment. Identification of the infectious agent by vitreous biopsy and blood cultures enables the ophthalmologist to choose a specific antibiotic treatment. Therapy consists of topical, intravitreal and systemic antibiotics or antimycotics often in combination with steroids and pars plana vitrectomy. As many of the patients with endogenous endophthalmitis are initially misdiagnosed (e. g. uveitis), it is important to consider this disease in the presence of suspicious symptoms.

An in vivo evaluation of Brilliant Blue G in animals and humans

BACKGROUND/AIMS

To evaluate the retinal toxicity of Brilliant Blue G (BBG) following intravitreal injection in rat eyes and examine the biocompatibility and the staining properties in humans.

METHODS

BBG was injected into the 11 rat eyes to evaluate toxic effects with balanced salt solution (BSS) serving as control. Retinal toxicity was assessed by retinal ganglion cell (RGC) counts and by light microscopy 7 days later. In addition, BBG was applied during vitrectomy for macular hole (MH) (n = 15) or epiretinal membranes (ERM) (n = 3) in a prospective, non-comparative consecutive series of patients. Before and after surgery, all patients underwent a complete clinical examination including measurement of best corrected visual acuity (VA) and intraocular pressure, perimetry, fundus photography and optical coherence tomography. Patients were seen 1 day before surgery and then in approximately four weeks intervals.

RESULTS

No significant reduction in RGC numbers and no morphological alterations were noted. A sufficient staining of the internal limiting membrane (ILM) was seen in patients with MH, while the staining pattern in ERM cases was patchy, indicating that parts of the ILM were peeled off along with the ERM in a variable extent. All MHs could be closed successfully. VA improved in 10 eyes (56%; 8/15 MH patients, 2/3 ERM patients), was unchanged in four eyes (22%; all MH patients) and was reduced in four eyes (22%; 3/15 MH, 1/3 ERM). No toxic effects attributable to the dye were noted during patient follow-up. The ultrastructure of tissue harvested during surgery was unremarkable.

CONCLUSION

Brilliant Blue provides a sufficient and selective staining of the ILM. No retinal toxicity or adverse effects related to the dye were observed in animal and human studies. The long-term safety of this novel dye will have to be evaluated in larger patient series and a longer follow-up.

Microbial contamination of multi-use ophthalmic solutions in Kenya

BACKGROUND/AIMS

Contaminated ophthalmic solutions represent a potential cause of avoidable ocular infection. This study aimed to determine the magnitude and pattern of microbial contamination of multi-dose ocular solutions at the Department of Ophthalmology, University of Nairobi, at the Kenyatta National Hospital, Kenya.

METHODS

101 vials were obtained for microbial examination after an average use of 2 weeks. The dropper tip and the residual eye drop were examined for contamination. The specimens were cultured, the number of colonies counted, the organisms identified and susceptibility testing to selected antimicrobial agents was done.

RESULTS

Six (6%) of the 101 analysed vials were contaminated: 4/77 vials (5%) from a multi-user setting and 2/24 vials (8%) from a single user setting. Three contaminations (3/38, 8%) occurred in vials from the eye ward, another three (3/59, 5%) in vials from the outpatient clinic. Most bacteria identified belonged to the normal commensal flora of the eye. Isolated contaminants were micrococci (n = 2), Staphylococcus epidermidis, Haemophilus sp, Bacillus sp and a Gram negative rod. The dropper tip was more often contaminated (n = 6) than the residual solution (n = 1), and only one vial showed a contamination of both the drop and the tip.

CONCLUSION

Our data show a contamination rate of 6%, which is in the lower range of data published on the contamination of eye drops elsewhere (0.07% to 35.8%).