Anterior Segment Disease Research Articles

Clinical Results with the Use of a Temporary Keratoprosthesis in Combined Penetrating Keratoplasty and Vitreoretinal Surgery

To evaluate surgical outcomes using a temporary intraoperative keratoprosthesis (KP) in patients undergoing combined pars plana vitrectomy (PPV) and penetrating keratoplasty (PKP). From January 2001 to August 2008, medical records of 23 patients undergoing combined KP/PPV/PKP for traumatic and nontraumatic corneal and retinal pathologies were studied. Only patients with >or=6 months follow-up were included. Patient characteristics, diagnoses, visual acuity, intraocular pressure, and status of the retina and cornea at baseline, and postoperatively on day 1, months 1 and 6, and yearly until the last follow-up, were collected. Functional (best-corrected visual acuity: improved, stable, worsened) and anatomic outcomes (clear corneal graft, retinal reattachment) were defined prior to review. Twenty-four eyes underwent combined KP/PPV/PKP (mean follow-up 36 months). At final follow-up, best-corrected visual acuity improved in 8 (40%) eyes, remained stable in 8 (40%), and worsened in 4 (20%). Corneal graft was clear in 18 (79%) eyes; 5 (21%) had graft failure. Retinal reattachment occurred in 22 (92%) eyes; 2 (8%) developed a localized traction retinal detachment not warranting additional surgery. Derangement in intraocular pressure was common (13 [54%] eyes). Three eyes (13%) showed signs of phthisis preoperatively that resolved with reestablishment of normal intraocular pressure postoperatively. Temporary KP during PPV/PKP surgery allowed surgical intervention in eyes with complex anterior and posterior segment disease. Corneal graft clarity and successful retinal reattachment was possible in the majority of eyes.

Comprehensive review of the effects of diabetes on ocular health

In light of the potentially devastating effects of diabetes on ocular health, it behooves the eyecare professional to pay close attention to ocular changes in their diabetic patients so that they can be treated early and effectively. In this article, anterior and posterior segment changes and disease are reviewed in depth, including extraocular, neurological and optic nerve changes. This article intends to provide a useful resource to clinicians regarding the full range of ocular complications associated with diabetes.

Posterior Segment Optical Coherence Tomography in Glaucoma

Unfortunately, glaucoma is essentially a silent disease that often goes unnoticed by the patient until damage is severe. Visual field testing is not an ideal method to diagnose and detect progression of glaucoma because of lack of sensitivity in the early course of the disease. Since structural changes in the RNFL and ONH may result in irreversible visual field loss,the earliest possible diagnosis of tissue damage is important in preventing further cell death. Of the many new technologies, optical coherence tomography (OCT) has emerged as an able diagnostic tool for analyzing the nerve fiber layer and evaluate optic nerve topography, and has aided in detecting structural change before functional loss. anterior and posterior segment disease processes. This article aims to elucide the role of posterior segment OCT in glaucoma management.

Traditional eye medicine use by newly presenting ophthalmic patients to a teaching hospital in south-eastern Nigeria: socio-demographic and clinical correlates

BackgroundThis study set out to determine the incidence, socio-demographic, and clinical correlates of Traditional Eye Medicine (TEM) use in a population of newly presenting ophthalmic outpatients attending a tertiary eye care centre in south-eastern Nigeria.MethodsIn a comparative cross-sectional survey at the eye clinic of the University of Nigeria Teaching Hospital (UNTH), Enugu, between August 2004 - July 2006, all newly presenting ophthalmic outpatients were recruited. Participants' socio-demographic and clinical data and profile of TEM use were obtained from history and examination of each participant and entered into a pretested questionnaire and proforma. Participants were subsequently categorized into TEM- users and non-users; intra-group analysis yielded proportions, frequencies, and percentages while chi-square test was used for inter-group comparisons at P = 0.01, df = 1.ResultsOf the 2,542 (males, 48.1%; females, 51.9%) participants, 149 (5.9%) (males, 45%; females, 55%) used TEM for their current eye disease. The TEMs used were chemical substances (57.7%), plant products (37.7%), and animal products (4.7%). They were more often prescribed by non-traditional (66.4%) than traditional (36.9%) medicine practitioners. TEMs were used on account of vision loss (58.5%), ocular itching (25.4%) and eye discharge (3.8%). Reported efficacy from previous users (67.1%) and belief in potency (28.2%) were the main reasons for using TEM. Civil servants (20.1%), farmers (17.7%), and traders (14.1%) were the leading users of TEM. TEM use was significantly associated with younger age (p < 0.01), being married (p < 0.01), rural residence (p < 0.01), ocular anterior segment disease (p < 0.01), delayed presentation (p < 0.01), low presenting visual acuity (p < 0.01), and co-morbid chronic medical disease (p < 0.01), but not with gender (p = 0.157), and educational status (p = 0.115).ConclusionThe incidence of TEM use among new ophthalmic outpatients at UNTH is low. The reasons for TEM use are amenable to positive change through enhanced delivery of promotive, preventive, and curative public eye care services. This has implications for eye care planners and implementers. To reverse the trend, we suggest strengthening of eye care programmes, even distribution of eye care resources, active collaboration with orthodox eye care providers and traditional medical practitioners, and intensification of research efforts into the pharmacology of TEMs.

Clinical decision paths in KPro Surgery

Abstract Purpose To analyse the currently available methods for treating very severe anterior segment disease, such as stem cell transplantation with amniotic membrane transplantation, lamellar and penetrating keratoplasty techniques, and the different Kpro´s currently available, in regard to the initial clinical findings, the potential complications encountered and the surgical requirements needed for the different techniques. Factors considered are: uni‐ or bilaterality, limbal stem cell status, dry eye status and availability of healthy teeth. Methods A systematic analysis of surgical options available for different stages of a variety of anterior segment diseases and currently published results of VA and complications Results With a systematic approach it becomes clear that some popular reconstructive surgical techniques should be avoided in cases where a very low chance of success is to be expected (e.g. amniotic membrane and stem cell transplantation and /or PKP in very dry eyes –&gt; these would have to be treated with OOKP). Conclusion Following a simple the clinical decision path the anterior segment surgeon will be presented with standardized guidelines for treating those patients where conventional surgical procedures have to be avoided and replaced by rather rarely performed KPro techniques.

Ocular manifestations in chronic granulomatous disease in Saudi Arabia

Chronic granulomatous disease (CGD) is a primary immunodeficiency disease caused by a genetic defect in the NADPH oxidase complex of phagocytic cells. Recent reports indicate that chorioretinal lesions are more common than previously suspected. In this study, ocular findings of CGD patients are described with particular emphasis on chorioretinal lesions as a potentially serious ocular complication of CGD. Medical records of CGD patients attending an immunodeficiency clinic at a tertiary care center from January 2004 to December 2006 were reviewed. Patients underwent full ophthalmologic examination. Patients with chorioretinal lesions were investigated for various causes of chorioretinitis. Molecular studies for common CGD-causing genes were performed in patients with chorioretinal lesions. This cohort included 32 CGD patients: 14 (44%) had abnormal eye findings, 11 (34%) had anterior segment disease, and 4 (12.5%) had chorioretinal lesions. Posterior segment findings consisted of uniformly similar hypopigmented atrophic punched-out chorioretinal scars around the arcades and mid-equator sparing of the macula. One patient had exudative hemorrhagic total retinal detachment in the right eye. Two siblings with chorioretinal lesions had mutation in CYBB, an X-linked gene. Another patient carried a missense mutation in NCF2, causing autosomal-recessive disease. While ocular manifestation is common in CGD, chorioretinal lesions seem less frequent. However, they present potential risk of visual loss; it is recommended that patients undergo regular ophthalmologic examinations. This report provides further evidence that chorioretinal lesions occur not only in X-linked, but they can also occur in the autosomal-recessive form of CGD.

Advances in anterior segment imaging and analysis.

Efforts to visualize and quantify key aspects of anterior segment ocular anatomy have fostered the development of many new imaging modalities and supportive technological advances in the last decade. This has been accompanied by an increase in the quantity and complexity of data available to the clinician. This article briefly reviews recent imaging advances and new challenges in the effective use of these complex datasets to solve clinical problems. The current revolution in corneal imaging includes two advancing fronts: new or improved imaging modalities and new methods of data representation. Areas of significant activity include increased speed and resolution, enhanced microstructural imaging, and marked increases in the amount of data available on the three-dimensional macrostructure and microstructure of the cornea. Some efforts to represent these data in clinically useful terms and to emphasize critical interpretation of the end-user data are reviewed. Recent advances in anterior segment imaging technology bring new opportunities and novel challenges to the end-user. These developments are capable of producing increasingly sophisticated three-dimensional representations of the anterior segment that will support novel applications for the diagnosis and treatment of anterior segment disease.

Branch Retinal Vein Occlusion: A Case Report and Update on a Newly Available Treatment Option

To evaluate the visual prognosis in eyes with branch retinal artery occlusion (BRAO).Retrospective, observational, consecutive case series.Retrospective medical record review of 52 consecutive eyes of 52 patients with BRAO seen at two vitreoretinal practices in Birmingham, Alabama. Only eyes with decreased central macular perfusion on fluorescein angiography (FA) were included. Eyes with anterior segment or optic nerve disease, lack of retinal whitening or a delay in arterial filling on FA, central retinal artery occlusion, and cilioretinal artery occlusion were excluded. The main outcome measure was presenting best-corrected visual acuity (BCVA) and its relationship to final BCVA.On presentation, 54% of eyes with BRAO had BCVA of 20/40 or better. At the mean 14-month visit, 60% of all eyes had visual acuity (VA) of 20/40 or better. VAs of 20/40 or better were retained by 89% of eyes with baseline BCVA of 20/40 or better. Only 14% of eyes with 20/100 or worse BCVA improved to 20/40 or better. Neither visible emboli (P ≥ .244) nor the region of macular involvement (P = .142) were significant with respect to visual improvement.Visual prognosis after BRAO seems to be correlated to presenting VA. Eyes with initial VA of 20/40 or better usually remained at 20/40 or better. Individuals with poor VA of 20/100 or worse generally did not show the significant improvement reported in previous studies.

Risk Factors, Microbiological Findings, and Clinical Outcomes in Cases of Microbial Keratitis Admitted to a Tertiary Referral Center in Ireland

To identify the risk factors for, and to report the microbiological findings and clinical outcomes of, severe microbial keratitis (MK). This was a retrospective study of all cases of presumed MK admitted to a tertiary referral center over a 2-year period (September 2001 to August 2003). Data recorded included demographic data, details relating to possible risk factors, results of microbiological studies, clinical findings at presentation, and clinical and visual outcomes. Ninety patients were admitted with a diagnosis of presumed MK during the study period. The mean age of patients was 45 +/- 32 years, and the male to female ratio was 47:43 (52.2%:47.7%). Predisposing risk factors for MK included contact lens wear (37; 41.1%), anterior segment disease (19; 21.1%), ocular trauma (13; 14.4%), systemic disease (5; 5.6%), and previous ocular surgery (1; 1.1%). Cultured organisms included gram-negative bacteria (17; 51.5%), gram-positive bacteria (11, 33.3%), acanthamoeba (2; 6.1%), and fungi (1; 3%). Visual acuity improved significantly after treatment [mean best-corrected visual acuity (+/-standard deviation) at presentation: 0.76 (+/-0.11); mean best-corrected visual acuity at last follow-up: 0.24 (+/-0.07); P < 0.001]. Secondary surgical procedures were required in 18 (20%) cases, and these included punctal cautery (1; 1.1%), tissue glue repair of corneal perforation (2; 2.2%), tarsorrhaphy (9; 9.9%), Botulinum toxin-induced ptosis (1; 1.1%), penetrating keratoplasty (3; 3.3%), and evisceration (2; 2.2%). Contact lens wear remains a significant risk factor for severe MK. MK remains a threat to vision and to the eye, but the majority of cases respond to prompt and appropriate antimicrobial therapy.

State of the Art Clinical Efficacy and Safety Evaluation of N-Acetylcarnosine Dipeptide Ophthalmic Prodrug. Principles for the Delivery, Self-Bioactivation, Molecular Targets and Interaction with a Highly Evolved Histidyl-Hydrazide Structure in the Treatment and Therapeutic Management of a Group of Sight-Threatening Eye Diseases

The exact biological functions of the aminoacyl-histidine dipeptides in ophthalmology are still unknown but they are the subject of intensive research activities at Innovative Vision Products, Inc. (IVP). Numerous studies have demonstrated, both at the tissue and organelle levels, that naturally occuring imidazole containing peptidomimetics possess strong and specific antioxidant properties, by preventing and reducing the accumulation of oxidised products derived from the lipid peroxidation (LPO) of biological membranes. Carnosine has been shown to act as a competitive inhibitor of the non-enzymatic glycosylation of proteins.Thus, carnosine may prevent and reverse (de-link) the formation of the advanced glycation end-products (AGEs), whose accumulation in the ocular tissues has been proposed to play a direct role in the etiology and pathogenesis of cataract and diabetic ocular complications (DOC). Besides, histidine-containing dipeptides are believed to act as cytosolic buffering agents. To compare the efficacy of L-carnosine and derivatives in inhibiting/reversing oxidative stress-induced reactions relevant for cataract pathogenesis. To assess the transglycation activity of carnosine versus representatives of a new group of synthetic carnosine histidyl-hydrazide analogs. To test the clinical efficacy of N-acetylcarnosine prodrug eye drops, developed by IVP's scientists, in decreasing the symptoms of age-related cataract. Antioxidant activity of L-carnosine and N-acetylcarnosine was studied in liposomes, a model of lipid membranes. Iron/ascorbate was used for induction of LPO and peroxidation products were measured. Second-generation carnosine analogs were synthesized and tested vs. L-carnosine for their ability to reverse the glycation process, ultimately resulting in the formation of the AGEs. Visual acuity and glare sensitivity was measured before and after 9-month of topical administration of N-acetylcarnosine eye drops in a randomized placebo-controlled cohort of patients presenting age-related uncomplicated cataract and non-cataract subjects of the same age range. L-carnosine operates as aldehyde and reactive oxygen species (ROS) scavenger in aqueous and lipid environments, preventing ROS-induced damage to biomolecules. L-carnosine and histidyl-hydrazide analogs present transglycation properties which could be used to decrease the occurrence of long term complications of AGE formation in DOC and age-related cataracts. In the patented ophthalmic formulations, the designed leucyl-histidylhydrazide (not hydrolizable by carnosinase substrate) is endowed with a highly evolved structure optimized for the bioactivation of a N-acetylcarnosine dipeptide prodrug, targeting therapeutics of the main DOC: cataract, diabetic retinopathy, central retinal vein occlusion, central retinal artery occlusion and neovascular glaucoma. Besides, the data support the clinical application of N-acetylcarnosine lubricant eye drops to compensate corneal acidosis. Nine-month treatment with N-acetylcarnosine resulted in improved visual acuity in subjects with cataract. Glare sensitivity was improved in subjects with cataract and in non-cataract older subjects. The results from the matched studies indicate that the N-acetylcarnosine-laden therapeutic contact lenses increasing the intraocular and systemic absorption of the active dipeptide carnosine ingredient, are an effective and well-tolerated bandage lens for anterior segment disease and for post-operative management of LASEK patients.This allows practitioners to prescribe extended wear of therapeutic contact lenses loaded with N-acetylcarnosine during medical treatment of cataracts, ocular complications of diabetes, primary open-angle glaucoma and potentially creates a healthier eye and body environment during healing. A number of clinically developed with alliance groups famous International brands of patented by IVP N-acetylcarnosine lubricant eye drops (Can-C, IVP C and D-Smile) are described with a quick reference guide for completing a vendor official registration in EC countries, U.A.E., Indonesia, Japan for human and veterinary use. In a separate development series of data Carcinine (beta-alanylhistamine) significantly protected photoreceptors against light-induced apoptosis, suggesting that this compound is sufficiently resistant to degradation with enzymatic hydrolysis and can be used in vivo representing new strategies in the anti-apoptotic ophthalmic therapy. Cataract is a major disease both in terms of number of people involved and economic impact. The research into causative factors and mechanisms to prevent the development of cataract is essential, particularly in developing countries where cataract surgery is often inaccessible. The results of this study provide a substantial basis for further evaluation of N-acetylcarnosine eye drops patented by IVP in the treatment and prevention of visual impairment in the temporal cross-sections of an older population several years apart. In the number of promotion studies this ophthalmic drug showed experimental and clinical potential for the non-surgical treatment of age-related cataracts. Comprehensive studies that investigate clinical, economic, and humanistic outcomes for the patient and society are conducted and will be described with different types of identified pharmacoeconomic evaluations to adequately assess the comparative value of current N-acetylcarnosine eye drops therapeutics for medical care and its place in future ophthalmic practices. Patients and the public expect that safe and cost-effective cataract medical care with N-acetylcarnosine therapeutic platform should be commissioned for them.

Branch Retinal Artery Occlusion: Visual Prognosis

To evaluate the visual prognosis in eyes with branch retinal artery occlusion (BRAO). Retrospective, observational, consecutive case series. Retrospective medical record review of 52 consecutive eyes of 52 patients with BRAO seen at two vitreoretinal practices in Birmingham, Alabama. Only eyes with decreased central macular perfusion on fluorescein angiography (FA) were included. Eyes with anterior segment or optic nerve disease, lack of retinal whitening or a delay in arterial filling on FA, central retinal artery occlusion, and cilioretinal artery occlusion were excluded. The main outcome measure was presenting best-corrected visual acuity (BCVA) and its relationship to final BCVA. On presentation, 54% of eyes with BRAO had BCVA of 20/40 or better. At the mean 14-month visit, 60% of all eyes had visual acuity (VA) of 20/40 or better. VAs of 20/40 or better were retained by 89% of eyes with baseline BCVA of 20/40 or better. Only 14% of eyes with 20/100 or worse BCVA improved to 20/40 or better. Neither visible emboli (P > or = .244) nor the region of macular involvement (P = .142) were significant with respect to visual improvement. Visual prognosis after BRAO seems to be correlated to presenting VA. Eyes with initial VA of 20/40 or better usually remained at 20/40 or better. Individuals with poor VA of 20/100 or worse generally did not show the significant improvement reported in previous studies.

In vivo confocal microscopy of the cornea

AbstractConfocal in‐vivo microscopy so far has not found its place in routine diagnostic of anterior segment disease. But progress has been made with recent developments mainly based on Laser scanning technology. This allows an optical sectioning of less than 5 μm thickness of high contrast and in well defined distances from the corneal surface as well as the examination of conjunctiva, sclera and the lid region.Information is given how to differentiate subpopulations of the epithelium (superficial, intermedial, basal cells) as well as overall epithelial thickness measurements. This is exemplified in normal individuals, contact lens wearers and patients with various kinds of ocular surface disease.Stromal keratocytes are displayed and quantified in different corneal layers. Information on keratocyte activation by higher densities of scatterers in the cytoplasm is possible, indicating increased metabolic activity.A more wide spread use of in‐vivo confocal microscopy will allow to judge on woundhealing in all kind of corneal disease and repair mechanisms such as corneal re‐innovation following refractive corneal surgery.Cell populations such as Langerhans cells are displayed and quantified allowing information on immunological corneal activity in‐vivo. Woundhealing modulation in Glaucoma filtering surgery can be displayed on a cellular level and microcyst formation depending on the influence of Mitomicin C and 5 FU are demonstrated at various stages after surgery. This information may influence the postoperative management considerably.In‐vivo confocal microscopy recently has become easy to handle with improved imaging quality and possibilities of quantitative evaluation of ocular surface structures.

Impact of long-term treatment of onchocerciasis with ivermectin in Ecuador: potential for elimination of infection

BackgroundOnchocerciasis is a leading cause of blindness worldwide, hence elimination of the infection is an important health priority. Community-based treatment programs with ivermectin form the basis of control programs for the disease in Latin America. The long-term administration of ivermectin could eliminate Onchocerca volvulus infection from endemic areas in Latin America.MethodsA strategy of annual to twice-annual treatments with ivermectin has been used for onchocerciasis in endemic communities in Ecuador for up to 14 years. The impact of ivermectin treatment on ocular morbidity, and O. volvulus infection and transmission was monitored in seven sentinel communities.ResultsOver the period 1990–2003, high rates of treatment coverage of the eligible population were maintained in endemic communities (mean 85.2% per treatment round). Ivermectin reduced the prevalence of anterior segment disease of the eye to 0% in sentinel communities and had a major impact on the prevalence and transmission of infection, with possible elimination of infection in some foci.ConclusionThe distribution of ivermectin in endemic communities in Ecuador might have eliminated ocular morbidity and significant progress has been made towards elimination of the infection. A strategy of more frequent treatments with ivermectin may be required in communities where the infection persists to achieve the objective of elimination of the infection from Ecuador. The elimination of the infection from an endemic country in Latin America would be a major public health achievement and could stimulate the implementation of elimination strategies in other endemic countries.

The long-term effect of experimental beta-radiation therapy on the human cornea

Background Radiation treatment of the human eye has been utilized in the United States since the early 1900s. Beta-radiation therapy was generally accepted by the medical community as a treatment option for a wide variety of anterior and posterior segment conditions from 1930 to the early 1950s. By the 1960s, beta-radiation therapy had fallen out of favor due to dangerous side effects; however an updated radiation procedure is now in use in ophthalmology to treat anterior and posterior segment disease. Case report A 64-year-old Caucasian female presented for a routine eye examination with a history of experimental beta-radiation treatments to the eyes as a teenager. A high astigmatic refractive error was present and best corrected visual acuity was 20/40 OD, 20/30 OS. Slit lamp examination showed severe disruption throughout the lower third of both corneas, appearing densely calcified with inferior vascularization. The left eye had a central descemetocele. The patient's ocular and visual conditions were relatively stable and required no special treatment as of the writing of this report, decades after her original treatments. Conclusion This patient is one example of the long-term effect of beta-radiation treatment on the eye. Ongoing care is needed to monitor the ocular health and vision of these individuals as radiation effects may necessitate observation and/or care throughout the patient's lifetime. Follow-up on more patients who underwent beta-radiation treatment decades ago, should it be possible to do so, would provide further insight into the long-term anterior segment changes that can occur as a result of such treatment.

Role of Swarming Migration in the Pathogenesis ofBacillusEndophthalmitis

Bacillus cereus causes one of the most rapidly blinding forms of bacterial endophthalmitis. Migration of B. cereus throughout the eye during endophthalmitis is a unique aspect of this disease that may contribute to intraocular virulence. This study was conducted to analyze the contribution of swarming and intraocular migration to the pathogenesis of experimental endophthalmitis. Eyes were injected intravitreally with 100 colony-forming units (CFU) of either wild-type, nonswarming, or swarming-complemented strains of B. cereus. Pathogenicity was compared throughout the course of infection by biomicroscopy, histology, electroretinography, and bacterial and inflammatory cell quantitation. Wild-type, nonswarming, and swarming-complemented B. cereus strains grew to a similar number in the vitreous throughout the course of infection. Unlike the wild-type and swarming-complemented strains, the nonswarming mutant did not migrate to the anterior segment during infection. The rate of decrease in retinal responses of eyes infected with the all strains was similar, resulting in near complete elimination of retinal function by 12 hours. All Bacillus strains caused similar degrees of posterior segment inflammation and retinal destruction. However, the accumulation of inflammatory cells in the anterior chamber, hyphemae, and corneal ring abscesses did not occur in eyes infected with the nonswarming mutant. The deficiency in swarming had little effect on retinal function loss or the overall course or severity of experimental B. cereus endophthalmitis. However, a deficiency in swarming prevented Bacillus from migrating to the anterior segment, leading to less severe anterior segment disease.

Pupil measurement using the Colvard pupillometer and a standard pupil card with a cobalt blue filter penlight

To compare scotopic pupil measurements obtained with a Colvard pupillometer with measurements taken with a printed pupil gauge and penlight with a cobalt blue filter attachment in mesopic and scotopic luminance. The Illinois Eye Institute, Chicago, Illinois, USA. Pupil measurements were taken of both eyes of 38 patients (76 eyes). Any subject presenting with anterior segment disease, fixed or dilated pupils, iris abnormalities, or a history of eye disease or eye trauma was excluded. At a mesopic luminance of 2.11 foot-candles, pupil measurements were taken with a Bernell pupil card and penlight with a cobalt blue filter attachment. At a scotopic luminance of less than 2.00 foot-candles, pupil measurements were taken with the Bernell card system and the Colvard pupillometer. In mesopic luminance, the mean pupil diameter was 5.17 mm (range 3.0 to 7.5 mm) with the Bernell card method. The mean difference between the Colvard in scotopic luminance and the Bernell card system in mesopic luminance was -0.04 mm (P = .0831). In scotopic luminance, the mean pupil diameter was 6.32 mm (range 4.0 to 8.0 mm) with the Bernell card method and 5.13 mm (range 3.0 to 7.5 mm) with the Colvard pupillometer, with a mean difference of -1.18 mm (P<.0001). The limits of agreement between the mesopic Bernell card system and the Colvard pupillometer were small (-0.32 to 0.24), whereas the limits of agreement between the scotopic measurements of both techniques were large (-2.18 to -0.18). Under both illuminance conditions, the Bernell card system with the cobalt filter measured a larger pupil size than the Colvard pupillometer. The measurement differences between the techniques were most pronounced at the lower illumination. The limits of agreement were larger under the lower illumination, indicating more variation between techniques. This study suggests that the Bernell card system with cobalt illumination provides a generous measurement of the pupil size compared with the Colvard pupillometer, which makes it an appropriate and cost-effective screening tool for refractive surgery evaluation.

Smith-method assessment of anterior chamber depth for screening for narrow anterior chamber angles

To compare the axial anterior chamber depth (ACD) using the Smith method, in patients under treatment for primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG), with an age-matched control group. Triplicate just-touching-slit-length (JTSL) measurements of the axial anterior chamber depth were determined in 198 eyes of 99 patients (39 control; 36 POAG; and 24 PACG) recruited from King Saud University clinics, Riyadh, Saudi Arabia. Goldmann tonometry and gonioscopy were carried out as a part of the patient's routine examination. Subjects with a history of intraocular surgery for glaucoma or any other anterior segment disease were excluded form the study. The average ACD estimate by the JTSL method were compared among the various groups. The average JTSL estimates were: Control group 2.33+/-0.68 mm (axial ACD estimate = JTSL estimate x 1.4); POAG group 1.98+/-0.97 mm; PACG group 0.65+/-0.41 mm. There was no significant reduction (P = 0.068) of the JTSL estimate in the POAG group, compared to the control group. There was a statistically significant (P < 0.001) reduction of the JTSL estimate in the PACG group, compared to both the control and POAG groups. The Smith-method JTSL technique may be used for non-invasive rapid screening, to help identify patients at risk of developing angle-closure, during routine examination of patients in the ophthalmology clinic.

Atypical presentation and review of the ICE syndrome

The different variants of the iridocorneal endothelial (ICE) syndrome were separately described in the early to mid-1900's and were eventually linked to a common etiology of an abnormal corneal endothelium. The ICE syndrome typically manifests in early to middle adulthood, usually occurs in women, and is almost always unilateral. Management of patients with any variant of the ICE syndrome challenges even the best clinicians. We present a 52-year-old patient with Chandler's syndrome. Our patient shared many of the classic characteristics of Chandler's syndrome, including peripheral anterior synechiae and corneal edema, with one unusual aspect--the patient was male. Details regarding the subsets of the ICE syndrome, differential diagnosis, and current understanding of the pathophysiology are also reviewed. The ICE syndrome is a progressive anterior segment disease that is quite difficult to manage. Corneal edema, increased IOP, and glaucoma are all sequelae of these conditions and, even in the best hands, are extremely challenging to manage. Today, nearly 100 years after Harms described the first patient with an ICE syndrome, we still do not know the exact mechanism for the corneal endothelial changes. Many investigations have been made into the causative agent or stimulus for abnormal endothelial growth in the ICE syndrome. No definitive proof has been established, but a relationship may exist with the Herpes Simplex and Epstein-Barr viruses. Further investigation is needed to determine the most-appropriate treatment and management of the ICE syndrome.

Ophthalmic genetics: diagnosis and therapy

With the virtual completion of the Human Genome Project and the mapping of approximately 30,000 human genes, we have reached a historical point in ophthalmic genetics research. A genomic map now exists that will help guide the effort to determine the genetic basis of retinal disease, myopia, anterior segment disease, and glaucoma. In this issue of the Ophthalmology Clinics of North America ,r ecent developments in ophthalmic genetics are highlighted with some special emphasis given to glaucoma, which has only relatively become an area of active genetics research. Conceptually, our understanding of glaucoma and other ophthalmic disease is likely to be on a genetic basis in the next decade. For instance, although glaucoma is a distinct form of optic neuropathy, several separate genes and a number of loci have now been identified that lead to this optic neuropathy, and patients with each of these genes have separate, definable characteristics in terms of the appearance of their optic nerves and response to medications. In the future,we should be ableto determine whether ornot a patient will respond well to treatment with medication, lasers, or surgery on the basis of which of the several glaucoma mutations they harbor. Understanding the specific mutations in each of these genes may be important for both prognosis and treatment. I have asked each of the authors in this issue to comment on the prospects for gene therapy as they pertain to the disease discussed in their respective articles. Genetic therapies are likely to be commonplace in the next century, though much remains to be worked through regarding them. New information on gene therapies is appearing daily, and articles such as these will likely be much more useful now than in 5 years. The articles in this issue have been carefully chosen and cultivated; as Guest Editor, I hope you will find them useful. I thank my long-time collaborators at the Casey Eye Institute, Mary Wirtz, PhD, Ted Acott, PhD, Preseton Alexander, Kris Weymann, and my mentors, including Richard F. Brubaker, MD,

Resting CD8 T cells recognize beta-galactosidase expressed in the immune-privileged retina and mediate autoimmune disease when activated.

Although the expression of class II major histocompatibility complex (MHC) in retina is extremely low, it is an established fact that activated CD4 T cells, specific for retinal antigens (Ags), mediate experimental autoimmune uveoretinitis (EAU). Conversely, CD8 T cells have not been shown to recognize Ag in the retina. This study investigated whether retinal-specific Ags are detected by class I MHC-restricted CD8 T cells. Using a CD8 T-cell clone (beta3) specific for an immunodominant epitope of beta-galactosidase (beta-gal), local Ag recognition was shown by transfer of activated beta3 cells into beta-gal transgenic (Tg) mice expressing beta-gal in the retina (hi-arr-beta-gal mice), or in the brain and eye (GFAP-beta-gal mice). Beta-gal-positive photoreceptor cells were damaged in the retina of hi-arr-beta-gal mice, and anterior segment disease was found in the eyes of GFAP-beta-gal mice. Ag recognition by resting CD8 T cells was also evaluated. Recovery of 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (CFSE)-labelled beta3 cells from hi-arr-beta-gal mice was slightly decreased compared to recovery from B10.A mice, while recovery from GFAP-beta-gal mice was transiently increased. Conversely, recovery of CFSE- cells increased in hi-arr-beta-gal mice, consistent with an Ag-dependent response. The CFSE content of the CFSE+ population was unchanged relative to beta3 cells recovered from controls. Intracellular cytokine responses of beta3 cells recovered from hi-arr-beta-gal and GFAP-beta-gal mice correlated with the number of cells recovered, regardless of CFSE content. Even though their production of interferon-gamma and tumour necrosis factor-alpha was affected little by transfer into hi-arr-beta-gal recipients, the ability of beta3 cells to mediate delayed-type hypersensitivity was inhibited in hi-arr-beta-gal mice. These results show that resting CD8 T cells are affected by the presence of Ag that originates in retina and, when activated prior to transfer, mediate pathogenic autoimmunity against retinal and other ocular targets.