Modified Surgical Techniques for Managing Intraoperative Floppy Iris Syndrome.

Purpose. To report a modified surgical strategy in the management of intraoperative floppy iris syndrome-associated iris prolapse. Methods. Prolapsed iris is left as is and a new corneal incision near the original wound but at a different site is created. Depending on the location of the original incision and the surgeon's preference, this additional incision can be used as a new port for phacoemulsification tip or can be the new site for the iris to securely prolapse, allowing for the surgery to proceed safely. Results. We present 2 cases of iris prolapse and inadequate pupil dilation in patients with IFIS. Along with our modified technique, additional iris retractors were placed to increase the workspace for the phacoemulsification tip. The cataract surgery was performed successfully without further complications in both cases. Conclusion. This surgical technique could be an adjunct to allow the surgeons to expand the armamentarium for the management of IFIS-associated iris prolapse.

Prevalence of Preoperative Corneal Astigmatism in Patients Undergoing Cataract Surgery at Mettapracharak Hospital, Thailand.

OBJECTIVE: To describe and analyze the demography and distribution of preoperative corneal astigmatism in patients undergoing cataract surgery at Mettapracharak Hospital. MATERIAL AND METHOD: The medical records of consecutive patients who had cataract surgery between October 1, 2010 and September 30, 2011 at Mettapracharak Hospital were retrospectively reviewed and analyzed. Patient demographic and keratometric data were collected and analyzed. RESULTS: The present study evaluated the keratometric data in 2,688 eyes of 2,671 patients who had cataract surgery with the mean age of 66.23±10.79 years. The mean corneal astigmatism was 1.09 D (range 0.00-8.50 D). Corneal astigmatism was higher than 1.00 D in 36.6%, between 0.51 D and 1.00 D in 37.9% and 0.50 D or less in 25.5% of eyes. The mean steep keratometry and flat keratometry values were 44.89±1.52 D and 43.81±1.57 D respectively. The magnitude of corneal astigmatism was positively correlated with age (p<0. 001) and there was a tendency for corneal astigmatism to increase with age above 50 years. Female had significantly steeper corneas than male. Corneal astigmatism was mainly against-the-rule (the steepest meridian at 180±30 degrees). The type of corneal astigmatism was strongly correlated with age. Against-the-rule astigmatism increased with older age. While aging decreased with-the-rule astigmatism. CONCLUSION: The present report showed the pattern of corneal astigmatism before cataract surgery in Thai governmental hospital, approximately one third of cataract patients had more than 1.00 D of astigmatism. This finding provide the important normative reference and help ophthalmologists to plan and manage the cost-effective correction of preexisting corneal astigmatism in cataract patients to achieve the best visual outcome.

The first rapid assessment of avoidable blindness (RAAB) in Thailand.

BACKGROUND: The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB) study in Thailand. METHODS: A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. RESULTS: The age and sex adjusted prevalence of blindness (presenting visual acuity (VA) <20/400), severe visual impairment (VA <20/200 but ≥20/400), and moderate visual impairment (VA <20/70 but ≥20/200) were 0.6% (95% CI: 0.5-0.8), 1.3% (95% CI: 1.0-1.6), 12.6% (95% CI: 10.8-14.5). There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. CONCLUSION: Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system.

Management of herpes simplex virus stromal keratitis: an evidence-based review.

Herpes simplex virus (HSV) stromal keratitis is a leading cause of corneal opacification and an important indication for penetrating keratoplasty. Based on several observational studies and clinical trials, the current standard of care includes topical corticosteroids and antivirals. However, corticosteroids have significant side effects, and antivirals are only beneficial if replicating virus is present. High-quality clinical trials investigating therapies for HSV stromal keratitis beyond corticosteroids and antivirals are lacking. Immune regulatory drugs, such as cyclosporine A, present attractive alternatives to managing HSV stromal keratitis, given the immune-mediated pathogenesis of stromal disease. Also, inhibiting viral reactivation in the latently infected ganglia through therapeutic vaccination will likely be the most efficient avenue to reduce recurrent HSV ocular disease. Our present aim is to review the current evidence-based treatment options for HSV stromal keratitis including and beyond the use of corticosteroids and antivirals and to cultivate insights into developing therapeutic vaccination strategies to inhibit HSV stromal keratitis recurrences.

Neurotrophic keratitis in a patient with disseminated lymphangiomatosis.

INTRODUCTION: Neurotrophic keratitis, a degenerative corneal disease caused by trigeminal nerve impairment, has many etiologies and remains very difficult to treat. METHODS: Case report of a 23-year-old male with a right corneal ulcer that failed to improve despite broad-spectrum antimicrobials. RESULTS: Prior diagnosis of disseminated lymphangiomatosis with a lesion in the right petrous apex effacing Meckel's (trigeminal) cave in conjunction with a history of nonhealing corneal abrasions suggested a neurotrophic etiology. Drawstring temporary tarsorrhaphy, in addition to antibiotics and autologous serum, lead to successful clearing of the infection and resolution of the corneal ulcer. Visual acuity improved from light perception (LP) at the peak of infection to 20/40 six weeks after treatment. CONCLUSIONS: To our knowledge, we report the first case of neurotrophic keratitis in a patient with disseminated lymphangiomatosis that caused a mass effect in Meckel's (trigeminal) cave leading to compression of the trigeminal nerve. The antibiotic-resistant corneal ulcer was successfully treated with drawstring tarsorrhaphy, confirming the utility of this therapeutic measure in treating neurotrophic keratitis.

Repeated, noninvasive, high resolution spectral domain optical coherence tomography imaging of zebrafish embryos.

PURPOSE: To demonstrate a new imaging method for high resolution spectral domain optical coherence tomography (SD-OCT) for small animal developmental imaging. METHODS: Wildtype zebrafish that were 24, 48, 72, and 120 h post fertilization (hpf) and nok gene mutant (48 hpf) embryos were imaged in vivo. Three additional embryos were imaged twice, once at 72 hpf and again at 120 hpf. Images of the developing eye, brain, heart, whole body, proximal yolk sac, distal yolk sac, and tail were acquired. Three-dimensional OCT data sets (501 x 180 axial scans) were obtained as well as oversampled frames (8,100 axial scans) and repeated line scans (180 repeated frames). Scan volumes ranged from 750 x 750 microm to 3 x 3 mm, each 1.8 mm thick. Three-dimensional data sets allowed construction of C-mode slabs of the embryo. RESULTS: SD-OCT provided ultra-high resolution visualization of the eye, brain, heart, ear, and spine of the developing embryo as early as 24 hpf, and allowed development to be documented in each of these organ systems in consecutive sessions. Repeated line scanning with averaging optimized the visualization of static and dynamic structures contained in SD-OCT images. Structural defects caused by a mutation in the nok gene were readily observed as impeded ocular development, and enlarged pericardial cavities. CONCLUSIONS: SD-OCT allowed noninvasive, in vivo, ultra-high resolution, high-speed imaging of zebrafish embryos in their native state. The ability to measure structural and functional features repeatedly on the same specimen, without the need to sacrifice, promises to be a powerful tool in small animal developmental imaging.

Facial and ocular injuries associated with methamphetamine production accidents.

PURPOSE: To evaluate the relative contribution of methamphetamine production-related accidents to facial and ocular injuries admitted to a regional burn unit. DESIGN: Retrospective observational case series. METHODS: Chart review of all patients admitted to the Burn Unit at the University of Iowa Hospitals and Clinics (UIHC) over a 16-month interval. RESULTS: Methamphetamine related accidents were responsible for thirteen (9.8%) of 132 patients admitted with facial burns to UIHC during the study period. All victims were male. In addition to facial burns, eight patients (14 eyes) suffered chemical or thermal burns of the ocular surface of Hughes grade I or worse. One patient required full-thickness skins grafts for cicatricial ectropion of all four eyelids. CONCLUSION: In endemic areas such as Iowa, methamphetamine production accidents contribute to as many as 10% of admissions to burn care units for facial and ocular injuries.

Immunotolerance toward native alphaA-crystallin in knockout mice deficient in the functional protein.

Immune response against self antigens is normally prevented by an elaborate immunotolerance mechanism. A potential problem for recipients of gene therapy is, therefore, an immune response against the newly introduced gene product. To examine this issue we tested the immune response to the native proteins in knockout (KO) mice in which the genes for alphaA- or alphaB-crystallin were disrupted by partial or complete gene deletion, respectively. alphaA- and alphaB-crystallins are two immunologically distinct polypeptides which form the large ( approximately 800 kDa) complex in the lens referred to as alpha-crystallin. When immunized with murine alpha-crystallin, alphaB-crystallin KO mice, in which the corresponding gene was completely deleted, responded well to the absent self antigen. In contrast, alphaA-crystallin KO mice, with the partial gene deletion, resembled wild type (WT) mice in being immunotolerant toward the native crystallin. Although no functional alphaA-crystallin could be detected in the lens of alphaA-crystallin KO mice, mRNA transcript coding for a truncated alphaA-crystallin gene was found in thymi of these mice, suggesting that thymic expression of a residual fragment of the protein is responsible for the tolerance induction. These data suggest that nonfunctional proteins may induce immunotolerance and protect recipients of gene therapy from immunity against the native proteins.