Hypoxia and the Prolyl Hydroxylase Inhibitor FG-4592 Protect Corneal Endothelial Cells From Mechanical and Perioperative Surgical Stress.

PURPOSE: To determine whether hypoxia preconditioning can protect corneal endothelial cells from mechanical stress and perioperative procedures mimicking Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: Preconditioning was delivered by 2 hours of 0.5% oxygen incubation in a hypoxia chamber or by exposure to the prolyl hydroxylase inhibitor FG-4592, which prevents hypoxia-inducible factor-1 alpha degradation. Damage to whole corneas was produced by brief sonication. To mimic use with DSAEK, FG-4592-preconditioned and control donor corneas were dissected with a microkeratome, and the posterior donor button was pulled through a transplant insertion device (Busin glide). The area of endothelial damage was determined by trypan blue staining. RESULTS: In all cases, hypoxia preconditioning or incubation with FG-4592 protected corneal endothelial cells from death by mechanical stress. Hypoxia-preconditioned human and rabbit corneas showed 19% and 29% less cell loss, respectively, relative to controls, which were both significant at P < 0.05. FG-4592 preconditioning reduced endothelial cell loss associated with preparation and insertion of DSAEK grafts by 23% relative to the control (P < 0.01). CONCLUSIONS: These results support the hypothesis that preconditioning by hypoxia or exposure to FG-4592 improves corneal endothelial cell survival and may also provide protection during surgical trauma.

Comparison of culture-negative and culture-positive microbial keratitis: cause of culture negativity, clinical features and final outcome.

PURPOSE: To determine the causes of culture negativity and compare clinical outcomes in patients with culture-negative (CN) keratitis versus culture-positive (CP) keratitis. METHODS: Medical and microbiology records of 60 patients, who presented at the L V Prasad Eye Institute, Bhubaneswar, between January 2009 and December 2010, and who were clinically diagnosed to have microbial keratitis were retrospectively reviewed. Detailed ocular examination was performed before corneal scraping was sent for microbiological workup. The data collected from each record included age, gender, predisposing factors (ocular and systemic), clinical presentation, management and outcome of treatment. RESULTS: The duration of symptoms and prior use of topical medication was significantly higher in the CN group (p=0.005, p=0.007, respectively). Infiltrate size (p=0.42) and history of ocular trauma (p=0.14) had no association. While patients in the CP group underwent 9 (30%) minor major surgical procedures and 14 (46.7%) major surgical procedures, patients in the CN group underwent 11 (36.7%) minor surgical procedures and 1 (3.3%) major surgical procedure. Success in treatment was achieved in 27 (90%) and 25 (83.3%) patients in CP and CN groups, respectively. The mean visual acuity (logMAR) at presentation in the CP group was 2.53 which improved to 1.83 at the last follow-up (p=0.0001). Similarly, the mean visual acuity (logMAR) at presentation in the CN group was 2.57 which marginally improved to 2.34 at the last follow-up (p=0.03). CONCLUSIONS: CN keratitis is associated with long duration of topical medication. The number of major surgical interventions in CN keratitis is significantly less compared with CP keratitis. However, the final outcome of treatment is similar in both CP and CN keratitis.

The efficacy of corneal debridement in the treatment of microsporidial keratoconjunctivitis: a prospective randomized clinical trial.

PURPOSE: To evaluate the efficacy of corneal debridement in the treatment of clinically diagnosed cases of microsporidial keratoconjunctivitis. DESIGN: Prospective, double-masked randomized clinical trial. METHODS: Patients with clinical features such as multifocal, coarse, raised, punctate, round to oval epithelial lesions in the cornea in slit-lamp examination with mild to moderate conjunctival congestion, suggestive of microsporidial superficial keratoconjunctivitis, were included in the prospective study. All patients were randomized into 2 groups. Group 1 patients underwent debridement with the help of a sterile #15 blade on a Bard-Parker handle, whereas only conjunctival swabs were taken from Group 2 patients. All patients were treated with ocular lubricants. RESULTS: One hundred and twenty patients with clinical features suggestive of microsporidial superficial keratoconjunctivitis were included in the study. The mean age was 34.3 ± 13.6 years (Group 1) and 35.8 ± 16.2 years (Group 2) (P = .59). The mean duration of symptoms was 6.8 ± 3.9 days (Group 1) and 7.2 ± 4.6 days (Group 2) (P = .61). Baseline characteristics showed no difference between the 2 groups. The primary outcome was the time from the presentation to complete resolution (ie, absence of corneal lesions) of the clinical signs and symptoms. The secondary outcomes were final visual acuity and residual corneal side effects and/or scarring, if any. The mean resolution time of the corneal lesions was 5.7 ± 4.0 days (Group 1) and 5.9 ± 3.9 days (Group 2) (P = .83). There was no significant difference in final visual outcome in the 2 groups. No serious side effects were observed. CONCLUSION: Debridement does not have any significant advantage in terms of resolution of the corneal lesions and final visual outcome in cases of microsporidial keratoconjunctivitis.

Role of liquid culture media in the laboratory diagnosis of microbial keratitis.

PURPOSE: To determine whether liquid culture media are helpful in the diagnosis of infectious keratitis. DESIGN: Retrospective noncomparative case series. SUBJECTS AND METHODS: This is a retrospective review of microbiology records of 114 corneal scraping samples from infectious keratitis patients. Samples were processed by corneal smear microscopy (potassium hydroxide with calcofluor white and Gram stains) and culture examination (5% sheep blood agar, sheep blood chocolate agar, Sabouraud dextrose agar, brain heart infusion, thioglycolate broth, and Robertson's cooked meat broth. Cases where at least 1 liquid medium was taken were included in the study and all cases were required to have significant growth in culture as per the institutional criteria. Results of smear examination and culture growth were analyzed. RESULTS: Out of 114 cases, 44 (38.59%) were bacterial, 62 (54.38%) fungal, and 8 (7.01%) were mixed (bacteria + fungus) infection. Thirty-eight out of 44 cases of bacterial keratitis (86.36%) were diagnosed by solid media alone (criterion 1) and 6 of 44 (13.63%) required liquid media for diagnosis (P < .001). In fungal keratitis, 61 of 62 cases (98.38%) were diagnosed using solid media alone (criterion 1) while 1 case required liquid media for diagnosis. In mixed infection, none of the cases required liquid media for diagnosis of fungal component; however, all 8 cases required liquid media for establishing bacterial component. CONCLUSIONS: Liquid culture media increase the chance of isolation of bacteria in pure bacterial and/or mixed infection; however, their role in isolating fungus is limited. Owing to overlap in clinical diagnosis of bacterial and fungal keratitis, we recommend inclusion of both solid and liquid culture media in the laboratory diagnosis of nonviral keratitis.

Clinical, radiologic, and genetic features in blepharophimosis, ptosis, and epicanthus inversus syndrome in the Indian population.

PURPOSE: To study the clinical, radiologic, and genetic features in Indian Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) patients. METHODS: A total of 33 clinically well characterized BPES cases who presented between 2009 to 2011 were recruited. Clinical evaluation consisted of ophthalmic and orthoptic examination. For orbital indices, computed tomography (CT) scan of orbits was performed. Genetic studies included cytogenetic analysis and molecular analysis of FOXL2 gene. RESULTS: Significant clinical findings included a high incidence of refractive error in 94%, amblyopia in 60%, and strabismus in 40% of BPES cases. Orbital radiologic indices on CT scan in BPES were found to be comparable to the control group. On karyotyping, 8 out of 33 (24%) cases harbored chromosomal abnormalities. These abnormalities included 46,XY;del(3qter), 46,XY;del(3q26.3), 46,XX;del(3q24-25), and 46,XY;del(3q26qter). On molecular analysis, a novel mutation consisting of heterozygous substitution at c1635 that replaced cytosine by thymidine was detected. CONCLUSIONS: To the best of our knowledge, this is the first study on clinical features in BPES patients of Indian origin. A high incidence of refractive error, strabismus, and amblyopia was found in BPES cases. Orbital imaging confirmed that clinical features are limited to soft tissue abnormalities, with no underlying bony changes. Cytogenetic studies showed that most chromosomal abnormalities in the Indian population are in the region of the long arm of chromosome 3. Results of molecular analysis indicate that there may be loci other than the FOXL2 gene, which are affected in BPES cases. Our study expands the existing mutation spectrum of FOXL2 gene.

Iris cysts: a review.

Iris cysts though uncommon, present diagnostic and therapeutic challenges. With the advent of better investigational modalities it is not so difficult to characterize iris cysts and differentiate them from uveal tumors. Management strategies however, are still not clearly defined and long term course especially of inclusion cysts of the iris remains dismal. In this review we present the classification, pathogenesis, differential diagnosis and management options along with long term clinical course of eyes with iris cysts.