Philosophical direction of ‘ophthalmic epidemiology'

Published in this second issue of Ophthalmic Epidemiology is a review article by Dr. David H. Sliney entitled ‘Epidemiological studies of sunlight and cataract: the critical factor of ultraviolet exposure geometry'. Ultraviolet radiation as a risk factor for cataract development is a hot and hotly debated controversy with conflicting results presented in a number of superb research studies by experienced ophthalmic epidemiologists. This review article by Dr. Sliney offers some insight as to why the results of these epidemiologic studies are not uniformly consistent; he points out some of the pitfalls associated with instruments we use to measure ultraviolet radiation in population-based studies, and the importance of considering the circumstances under which ultraviolet exposure to the human eye is measured, whether it be by direct measurement of ultraviolet light impinging upon the eye, questionnaire of ultraviolet light exposure history, tables of resident area of sunlight or ultraviolet A, B, or C exposure or by other modalities of ultraviolet determinations. Using the information provided by Dr. Sliney in this review article may help future investigators improve the precision of instruments used in epidemiologic studies to quantify ultraviolet light impinging upon the human eye. Improvement of the precision of collected data can only reduce the variance of findings among studies on the association of ultraviolet radiation as a cause of age-related cataract. A similar issue is raised by Christen and associates in the article published in this same issue of Ophthalmic Epidemiology, ‘Confirmation of self-reported cataract in the Physicians’ Health Study', a well-conducted and well-respected study, that points out the need for independent confirmation of self-reported cataracts as recorded by questionnaire, to improve the accuracy of diagnosis of a disease whose risk factors are under investigation. A dictum taught me by my mentors at Johns Hopkins University, Drs. Philip Sartwell and George Comstock, that because of the imprecision and variance of epidemiologic measurement instruments, it takes many studies ‘like swallows to make a spring’ to confirm risk-factor relationships to a given disease. The often cited, numerous controversial studies on the association of cigarette smoking and lung cancer which were published long before it became clear that cigarette smoking was the major risk factor in that disease, emphasize the role of multiple studies in confirming an association between risk factor and disease, even when it is readily obvious in hind sight. I personally feel that review articles, published in ophthalmic journals, serve an essential function in the advancement of ophthalmic research. Periodic review articles on a particular ocular disease, by summarizing the known infomation about that particular disease up to that point in time, help current investigators plan future research based upon the balanced review of past knowledge. No current ophthalmic or epidemiologic journal is committed to consistently publishing those review articles necessary to provide a readily available repository of critical information, presented in a balanced perspective by experts in the field, for citation by researchers to further future research advances in particular fields of ophthalmic epidemiologic investigation.

The stimulus for Dr. Sliney's article came from the recent World Health Organization Report of an Informal Consultation on ‘The Effects of Solar UV Radiation on the Eye', convened by the WHO Prevention of Blindness Programme and the w HO Division of Environmental Health. This consultative study was stimulated in part by substantiated observations of ozone depletion at both polar regions of the earth and the logical question of what the potential effect of increased ultraviolet radiation on the eye in these areas may be, based upon the known ultraviolet exposure data currently available. Dr. Thylefors, Head of the WHO Prevention of Blindness Programme, has allowed Ophthalmic Epidemiology to publish portions of this consultative report in order to disseminate, to the general ophthalmic community, this ‘state-of-the-art’ information on the relationship of ultraviolet radiation and potential ocular damage. The article by Dr. Sliney, who contributed to the WHO report, is just the first of several review articles to be published on this subject by Ophthalmic Epidemiology; the putative relationship of ultraviolet exposure to cataract development has importent environmental, social, economic and health-related importance. Dr. Paul Dolin, a member of the w HO consultative team, has written an article, accepted in the next issue of Ophthalmic Epidemiology, which provides suggested epidemiologic studies that might help us in further investigation of the relationship of ultraviolet radiation and cataract development. Professor Gordon Johnson, also a contributor to the WHO consultation, has submitted a review paper on ultraviolet light exposure and its overall effect on the eye and adnexa, except for cataract and macular degeneration, which will be published in a future issue of Ophthalmic Epidemiolgy.

One of the reasons I accepted the major undertaking necessary to bring ‘Yet another Journal’ into the field of ophthalmic information overload, comes from my exasperation from attending many meetings over my 25 years as an ophthalmic epidemiologist where I felt that important papers and posters were presented and I wished that I were able to review in detail the methodology, results and discussion of the research presented; papers that were stimulating, provocative, controversial, methodologic, with negative results, positive results, or otherwise, which I thought worthy of publication to advance the field of ophthalmic epidemiologic research. I have seen research on specific areas repeated by subsequent investigators because no such repository of knowledge, where past research, be it positive or negative, could be found, had been published. Most ophthalmic and epidemiologic journals cannot, with their wide obligations to broad areas of readership, publish all the ‘nuts-and-bolts’ articles essential to provide the repository of information necessary to ophthalmic epidemiologists. These are the articles that need to be published, review and original articles, that form the basic building blocks which current researchers in ophthalmic epidemiology can use as foundations for future investigations. Ophthalmic Epidemiology is committed to providing the repository of information upon which new ideas can evolve based upon the building blocks of the past. Part of this foundation is the depository provided by review articles, special topics, methodologic studies, and negative results which I will encourage, so that others in our footsteps do not repeat our repetitious failures and successes out of ignorance, but can use our past footsteps to lead the march to future advances in the conquest of world blindness.     

Cataract extraction in a major ophthalmic hospital: Day‐case or overnight stay?

Purpose : Cataract surgery is increasing in Australia and represents a significant burden on limited health resources. This study examines the frequency and outcomes of cataract surgery for patients who were hospitalized overnight compared with those treated as day surgery cases. Methods : Medical records of 671 consecutive admissions for cataract surgery at the Royal Victorian Eye and Ear Hospital were reviewed. Data analysed included demographic features, insurance status, length of hospitalization, ophthalmic conditions, medical conditions, social problems and planned surgical technique. Ophthalmic and anaesthetic complications, active ophthalmic and medical interventions were also studied. Results : Of the 671 patient admissions for cataract during the study period, 226 (33.4%) were hospitalized overnight. Factors significantly associated with overnight hospitalization in univariate analyses include older age, female sex, country residence, Veterans’ Affairs insurance, monocular vision status, pre‐existing ischaemic heart disease, pre‐existing asthma/chronic obstructive lung disease, absence of carer, transportation problems, planned extra‐capsular cataract extraction technique, ophthalmic complications and active ophthalmic and/or medical interventions. After adjusting for possible confounding factors using backwards stepwise multivariate logistic regression models all except pre‐existing ischaemic heart disease and opthalmic complications were significantly associated with overnight admission for cataract surgery. In total, 14 cases (2.1%) needed active ophthalmic and/or medical interventions, 13 overnight cases and one day case. Conclusions : These data suggest that many patients who are hospitalized overnight for cataract surgery could be safely treated as day cases. Such a shift in the pattern of care for cataract surgery could provide a significant potential for health care savings.     

Recent advances in ophthalmic anterior segment imaging: a new era for ophthalmic diagnosis?

Anterior segment imaging is a rapidly advancing field of ophthalmology. New imaging modalities, such as rotating Scheimpflug imaging (Pentacam-Scheimpflug) and anterior segment optical coherence tomography (Visante OCT and Slit-Lamp OCT), have recently become commercially available. These new modalities supplement the more established imaging devices of Orbscan scanning slit topography and ultrasound biomicroscopy (UBM). All devices promise quantitative information and qualitative imaging of the cornea and anterior chamber. They provide a quantitative angle estimation by calculating the angle between the iris surface and the posterior corneal surface. Direct angle visualisation is possible with the OCT devices and UBM; they provide images of the scleral spur, ciliary body, ciliary sulcus and even canal of Schlemm in some eyes. Pentacam-Scheimpflug can measure net corneal power, a feature particularly useful for cataract patients having undergone previous corneal surgery. Anterior segment OCT can measure corneal flap depth following LASIK and anterior chamber width prior to phakic intraocular lens implantation. The arrival of the new imaging devices may herald the dawn of a new era for ophthalmic diagnosis, particularly in view of the ease and non-contact nature of examination.     

An immunohistochemical study of the ‘snowbank’ in a case of pars planitis

Purpose: To characterize the extracellular matrix and cellular components of a ‘snowbank’ removed during vitreous surgery for treatment of retinal detachment complicating pars planitis. Methods: The ‘snowbank’ was examined using immunohistochemical techniques and a panel of monoclonal and polyclonal antibodies directed against glial fibrillary acidic protein (GFAP), cytokeratin, alpha smooth muscle actin, tenascin, laminin, fibronectin, and collagen types I, II, and III. Results: The ‘snowbank’ was acellular except on the uveal side where there were cytokeratin-positive retinal pigment epithelial cells. There were no cells positive for the glial cell marker GFAP and the myofi- broblast cell marker alpha smooth muscle actin. The extracellular matrix of the ‘snowbank’ contained tenascin and collagen types I, II, and III. There was no immunoreactivity for laminin and fibronectin. Conclusion: These results on the immunohistochemical components of the ‘snowbank’ may be useful in clarifying the nature of the chronic inflammatory process in pars planitis. They indicate extensive tissue repair and remodeling, leading to major loss of function.     

Baerveldt glaucoma implant with Supramid© ripcord stent in neovascular glaucoma: a case series

AIM: To report the outcome of Baerveldt glaucoma implant (BGI) with Supramid© ripcord use in neovascular glaucoma (NVG). METHODS: We retrospectively evaluated the surgical outcome of the BGI with Supramid© 3/0 ripcord stent in patients with NVG. No tube ligation or venting slits were performed. Supramid was removed after 3mo if the target intraocular pressure (IOP) was not achieved. Surgical success was defined as IOP≤21 mm Hg with (qualified success) or without IOP-lowering medications (complete success). RESULTS: Twenty-six eyes from 24 patients were included in the study. The median duration of follow-up was 4 [interquartile range (IQR)=1-5]y, ranging from 0.5 to 5y. IOP decreased by a mean of 24.2 mm Hg (59.7%); from a mean of 40.5±12.6 mm Hg at baseline to 16.3±11.9 mm Hg, P≤0.001. The number of glaucoma medications reduced from a median of 5 (IQR=5-6) to 1 (IQR=0-2, P≤0.001) at the final follow-up. Overall success rates were 88.0% at 1y, 34.8% at 3y, 66.7% at 4y, and 50% at 5y. Hypertensive phase (HP) in the first 3mo occurred in 15/26 eyes (57.7%) with a mean IOP of 31.1 mm Hg. CONCLUSION: BGI with Supramid© ripcord stent gives close to 90% of the overall survival rate at the final follow-up without significant early hypotony. However, early HP is still a challenge.     

Occurrence of motility disorders in patients undergoing tube surgery—consecutive,retrospective follow-up case series analysis

Graefe's Archive for Clinical and Experimental Ophthalmology - The two glaucoma drainage devices (GDD) Ahmed and Baerveldt tubes are most commonly used for the treatment of refractory glaucoma....     

Solitary fibrous tumor of the orbit: is it rare? Report of a case series and review of the literature

PURPOSE: The real incidence of solitary fibrous tumor (SFT) of the orbit is unknown, but it seems that since it was first described in 1994, orbital SFT has been increasingly recognized. We believe that the orbital SFT is a relatively common tumor and that it should be considered in the differential diagnosis of any orbital tumor. DESIGN: Interventional case series. PARTICIPANTS: Four new cases of orbital SFT. METHODS: Four patients affected by solitary fibrous tumor of the orbit are described. One patient experienced a recurrent SFT shortly after initial surgical excision performed elsewhere. Thirty-eight cases have been reported in the literature in 7 years. RESULTS: The number of orbital SFTs reported has been increasing, reaching an average of more than five tumors reported per year. Since the first orbital SFT was described in 1994, 37 cases have been reported in the literature. We add four new cases in our series, including a recurrent tumor. A total of 42 cases have now been described, eight with recurrences. Malignant transformation occurred in one case. CONCLUSIONS: We believe that before 1994, the diagnosis orbital SFT was confused with other benign orbital tumors, such as fibrous histiocytoma and hemangiopericytoma because of a lack of use of immunohistochemical techniques. This entity should now be considered relatively common and should be included in the differential diagnosis of orbital tumors in any age group. Local recurrences of SFT are possible and usually follow an incomplete initial excision. Recurrent tumors in the orbit have shown the tendency to infiltrate the surrounding tissues and the bone, rendering complete secondary excision more difficult. Recurrent orbital SFT also has the potential for malignant transformation. The treatment of choice of orbital SFT is complete surgical excision and careful follow-up. Considering the more aggressive course followed by recurrent tumor, correct diagnosis and management is essential.     

Superior ophthalmic vein thrombosis: A rare complication of Graves’ orbitopathy

Superior ophthalmic vein thrombosis is a rare, life- and sight-threatening complication of both infectious and inflammatory orbital disease as well as hypercoagulable state. Only one case of superior ophthalmic vein thrombosis due to thyroid eye disease has been reported in the literature. This article describes the diagnosis and management of a case of superior ophthalmic vein thrombosis due to Graves’ orbitopathy. Early diagnosis is critical to facilitate timely therapeutic intervention. Superior ophthalmic vein thrombosis should be considered in the differential diagnosis of acute on chronic proptosis in the setting of Graves’ orbitopathy, and may represent and under-recognized and under-diagnosed clinical entity.     

Use of Bowman’s membrane electrocautery in blind eyes with painful bullous keratopathy not amenable to corneal transplantation: a retrospective case series

Graefe's Archive for Clinical and Experimental Ophthalmology - This study evaluated the safety and efficacy of Bowman’s membrane electrocautery in blind painful eyes with bullous...     

Corneal changes in ectrodactyly–ectodermal dysplasia–cleft lip and palate syndrome: case series and literature review

The aim of this study is to describe the corneal changes in three unrelated patients with ectrodactyly-ectodermal dysplasia-cleft lip and palate (EEC) syndrome and review the literature on the possible etiology and clinical presentation of similar cases. Case 1 is an 18-year-old female with cleft lip and palate, syndactyly, and bilateral corneal pannus superiorly and inferiorly. She was initially diagnosed and treated as herpes simplex virus keratitis. Case 2 is a 3-year-old female born with cleft lip and palate, absent radial digits in both hands, and bilateral lacrimal stenosis. She developed progressive stromal scarring and neovascularization in both eyes. Her cornea perforated after developing infectious ulceration. Case 3 is a 49-year-old male with cleft palate, claw-hand deformities, absent meibomian glands and lacrimal duct, right ankyloblepharon, and a superior wedge-shaped opacity in the left cornea. The clinical findings demonstrated the different spectrum of keratopathy seen in patients with EEC. All patients were treated medically and without any surgical intervention. Limbal stem cell deficiency (LSCD) is presumed to be the cause in all three cases. Corneal changes in EEC can have variable presentation. LSCD seems to be the etiology of such keratopathy. Recurrent infection from lacrimal drainage obstruction and tear film instability are other risk factors for disease severity and progression.     

Ranibizumab as adjuvant in the treatment of rubeosis iridis and neovascular glaucoma—results from a prospective interventional case series

Background

To evaluate the capability of adjuvant intraocular ranibizumab (Lucentis®) injections in the treatment of rubeosis and intraocular pressure in patients with rubeosis and neovascular glaucoma.

Methods

Ten eyes with rubeosis (R) and ten eyes with neovascular glaucoma (NVG) received Lucentis® injections (ranibizumab 0.5 mg/0.05 ml) in this prospective, monocenter, 12-months, interventional case series. The primary efficacy outcome measure was the change of degree of iris rubeosis as documented by iris fluorescein angiography measured after 12 months. Secondary outcomes were intraocular pressure (IOP), best-corrected visual acuity (BCVA, logMAR), numbers of additional interventions or antiglaucoma medications administered after injection, the gonioscopic status of the anterior chamber angle, and central retinal thickness.

Results

In the R group, 3.6 injections and in the NVG group 2.3 injections of Lucentis® were administered. Additional treatments were photocoagulation (n?=?19), cyclodestructive procedures (n?=?9), cryopexy (n?=?3), and vitrectomy (n?=?1). The mean stage of rubeosis was 3.4?±?0.7 in the R group and 3.6?±?0.8 in the NVG group at baseline. At month 12, the rubeosis was almost resolved in the R group (0.1?±?0.3, p?<?0.001), and decreased significantly in the NVG group (0.7?±?1.1, p?<?0.001). In the NVG subgroup, mean IOP was 41.4?±?13.4 mmHg at baseline, which decreased rapidly (18.2?±?12.3, day-14, p?=?0.005) and stabilized during the follow-up (15.6?±?2.0 mmHg, p?<?0.05). BCVA improved significantly in both groups (p?<?0.05, at month 12).

Conclusions

Injection of 0.5 mg ranibizumab appears to be beneficial as an adjuvant treatment in neovascular glaucoma and rubeosis due to its anti-angiogenic properties and its ability to prevent establishment or progression of anterior chamber angle obstruction. Conventional therapeutic procedures addressing the retinal ischemia are still required in a stage-wise treatment approach.