Corneal Response to Scleral Contact Lens Wear in Keratoconus.

OBJECTIVE: To verify corneal alterations in patients with keratoconus who wear scleral contact lenses (ScCLs), focusing on corneal endothelial assessment. METHODS: Scleral contact lenses were fitted in 22 patients with keratoconus. During a 90-day follow-up, patients were assessed in three visits: at baseline, after 30 days, and after 90 days. Patients underwent visual acuity measurement, slitlamp biomicroscopy of the anterior segment, specular microscopy of the corneal endothelium, corneal pachymetry, measurement of the clearance between the cornea and the lens, and follow-up of ectasia. RESULTS: Variables related to endothelial morphology and pachymetry values did not change significantly over time. Central clearance measurements decreased in the 90-day period. No progression of corneal ectasia was observed, neither were infectious or inflammatory processes in the same period. CONCLUSION: Daily wear of ScCLs in patients with keratoconus was not associated with adverse effects on the cornea or endothelium over a period of 90 days nor was there evidence of disease progression. Central clearance values diminished over that period, but the significance of this observation remains unclear.

Clinical Aspects of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis With Severe Ocular Complications in Brazil.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute and potentially fatal inflammatory vesiculobullous reactions that affect the skin and mucous membranes, and which are most often triggered by particular medications and infections. In Brazil, the drugs most frequently associated with TEN and SJS include cold medicine such as dipyrone and NSAIDs, followed by carbamazepine, phenobarbital, penicillin, and allopurinol. Genetic variations have been found to increase the risk of SJS/TEN in response to triggering factors such as medications. The most closely associated genes found in Brazilian cold-medicine-related SJS/TEN patients with severe ocular complications are HLA-A*66:01 in those of mixed African and European ancestry and HLA-B*44:03 and HLA-C*12:03 in those of solely European ancestry. Our classification system for grading ocular surface complication severity in SJS/TEN patients revealed the most severe complications to be limbal stem cell deficiency and dry eye. Changes to the conjunctival flora have also been observed in SJS/TEN patients. Our group identified bacterial colonization in 95% of the eyes (55.5% of which were gram-positive cocci, 25.5% of which were gram-negative bacilli, and 19% of which were gram-positive bacilli). Several new treatment options in the acute and chronic ocular management of the SJS/TEN patients have been described. This article highlights some Brazilian institutions' contributions to ocular surface care in both the acute phase (including the use of amniotic membrane transplantation) and the chronic phase (such as eyelid margin and fornix reconstruction, minor salivary gland transplantation, amniotic membrane and limbal transplantation, scleral contact lenses, anti-angiogenic eyedrops for corneal neovascularization, ex-vivo cultivated limbal epithelium transplantation, conjunctival-limbal autografting, oral mucosa transplantation, and keratoprosthesis).

Galectin-3: role in ocular allergy and potential as a predictive biomarker.

AIMS: To evaluate galectin-3 (Gal-3), a ß-galactoside binding protein, as a possible biomarker in ocular allergy and further investigated the role of endogenous Gal-3 in a murine model of ovalbumin (OVA)-induced allergic conjunctivitis (AC). METHODS: Conjunctival impression cytology specimens from control and patients with severe vernal keratoconjunctivitis, treated or untreated, were used to evaluate Gal-3 expression by immunocytochemistry. To investigate the mechanism of action of Gal-3, OVA-immunised BALB/c male wild-type (WT) and Gal-3 null (Gal-3-/-) mice were challenged with eye drops containing OVA on days 14-16 with a subset of animals pretreated with 0.03% tacrolimus (TC) or dexamethasone (Dex). RESULTS: Patients with AC and OVA-sensitised WT mice exhibited increased levels of Gal-3 in the conjunctiva compared with control, an effect reverted by the action of Dex and TC therapy. Twenty-four hours after the final OVA challenge, total and anti-OVA IgE levels increased significantly in the blood of OVA-sensitised WT and Gal-3-/- mice compared with controls, supporting the efficacy of the AC model. The lack of endogenous Gal-3 exacerbated the local inflammatory response, increasing the influx of eosinophils and mast cell activation. Additionally, OVA-sensitised Gal-3-/- animals exhibited increased CD4+ expression in the eyes as well as eotaxin, IL-4, IL-13 and interferon-γ levels in the tear fluid compared with WT animals. CONCLUSION: Gal-3 contributes to the pathogenesis of ocular allergy and represents a relevant therapeutic target.

Postoperative subconjunctival corticosteroid injection to prevent pterygium recurrence.

PURPOSE: To report the outcome of postoperative subconjunctival injection of triamcinolone in eyes that underwent pterygium surgery and were at risk for recurrence. METHODS: Twelve eyes of 11 patients with primary (7 eyes) or recurrent (5 eyes) pterygia underwent excision and conjunctival autografting (4 eyes, 33.3%), amniotic membrane grafting (6 eyes, 50%), or both (2 eyes, 16.6%). All of these eyes had signs that were considered to be risk factors for recurrence (conjunctival inflammation, hemorrhage, granuloma, and fibrovascular proliferation); accordingly, they also underwent subconjunctival injection of triamcinolone. RESULTS: Among the 11 patients, there were 8 (72.7%) men and 3 (27.3%) women; the mean age was 41 years (range, 20-56 years). In 5 (41.7%) eyes, the pterygium was graded as T2 (intermediate) and in 7 (58.3%) eyes was graded as T3 (fleshy). The time between surgery and the first injection ranged from 2 to 5 weeks (mean, 3.4 weeks), and 1-3 injections were necessary (mean, 1.7) to achieve the desired effect. After injection, 1 (8.3%) eye developed inflammation, and 2 (16.7%) eyes from another patient developed intraocular hypertension that was controlled with a topical beta-blocker. The follow-up after the last injection ranged from 8 to 36 months (mean, 14.5 months); only 1 recurrence (grade 3) occurred during this period. CONCLUSIONS: The postoperative use of subconjunctival triamcinolone seems to benefit patients at increased risk of pterygium recurrence. It is relatively safe and is accompanied by few complications, but controlled and prospective studies are necessary to confirm its efficacy.

Diagnosis of epithelial ingrowth after penetrating keratoplasty with confocal microscopy.

PURPOSE: To report confocal microscopy use in the clinical diagnosis of epithelial ingrowth after penetrating keratoplasty (PKP). METHODS: A 36-year-old female patient with keratoconus developed a well-delimited posterior hazy membrane covering the inferior two thirds of the cornea 3 months after an uneventful PKP. A posterior corneal line was present resembling an endothelial graft rejection line, but with no keratic precipitates or corneal edema. Ocular hypertension was not observed. Confocal microscopy was performed to elucidate the diagnosis. RESULTS: Confocal microscopy showed epithelium and stroma with normal findings. Two distinct cellular types were presented at the endothelium layer. Enlarged endothelial cells were observed in the superior part of the cornea up to the leading edge of the hazy membrane. In the middle and inferior part of the graft, the cells were larger, with polygonal shape and easily recognizable hyperreflective nuclei, suggestive of epithelial cells. With these confocal microscopy findings, the patient was promptly submitted to another PKP. Histologic analysis confirmed the diagnosis of epithelial ingrowth. CONCLUSION: Confocal microscopy imaging technique seems to be a useful tool in the early diagnosis of epithelial ingrowth after PKP.

Toll-like receptors and the eye.

PURPOSE OF REVIEW: This review will describe the structure, expression/distribution and functional activity of Toll-like receptors, in particular in the ocular structures. It will also discuss innate and adaptive immune responses, by exploring the possible modulation/regulation of innate and adaptive immunity by Toll-like receptors, in view of recent findings observed in the ocular surface. RECENT FINDINGS: Current knowledge indicates that Toll-like receptors represent essential elements in host defence against pathogens, a prerequisite to the induction of adaptive immune responses. The expression/distribution of Toll-like receptors in the healthy eye highlights the possible function of Toll-like receptors in both innate and adaptive responses during pathological conditions of the ocular surface. SUMMARY: Recent findings have greatly increased the knowledge of the possible role of Toll-like receptors in innate and adaptive immune responses. Toll-like receptors seem to play different roles in a wide range of activities of the immune system, and might represent an exclusive link between innate and adaptive responses under pathological conditions. Recent studies in ophthalmology have highlighted the role of Toll-like receptors in infections (keratitis) as well as in allergic states of the ocular surface. This review thus describes the relationship between Toll-like receptors and the main immune/structural cells taking part in inflammatory disorders. Understanding the complex mechanisms underlying Toll-like receptor localization and function will provide additional data that might help devise novel therapeutic approaches involving Toll-like receptors and their agonists, in an attempt to modulate the biased immune system.

Amniotic membrane transplantation for partial and total limbal stem cell deficiency secondary to chemical burn.

PURPOSE: To evaluate the surgical outcome of preserved amniotic membrane transplantation (AMT) for ocular surface reconstruction in chemical burn with limbal stem cell deficiency. DESIGN: Prospective, noncomparative, interventional case series. PARTICIPANTS: Twenty eyes of 20 consecutive patients with limbal stem cell deficiency secondary to ocular chemical injury. INTERVENTION: AMT with or without adjunctive limbal transplantation using limbal tissue from either the healthy contralateral eye (CLAU) or a living related donor (lr-CLAL). MAIN OUTCOME MEASURES: Reconstruction of corneal epithelium (clear appearance without epithelial defect, normal fluorescein permeability and the absence of conjunctiva-derived goblet cells on impression cytology), decrease in corneal vascularization and improvement in visual acuity. RESULTS: With a mean follow-up time of 19 months (range, 8-27 months), satisfactory ocular surface reconstruction was obtained in 15 eyes (75%), with reduced inflammation and vascularization of the ocular surface and a mean epithelialization time of 3.3 weeks. Success was observed in all cases of partial limbal stem cell deficiency (PLD) and in 68.75% (11 eyes) of cases of total limbal stem cell deficiency (TLD). Surgical failure was observed in five severe cases (31.25%). A significant visual improvement was observed in all cases after surgery, except for 2 eyes that maintained preoperative visual acuity. CONCLUSIONS: AMT seems to be an efficient adjunct for ocular surface reconstruction in chemical burns with PLD. When performed in conjunction with limbal stem cell transplantation, it is also effective in most cases of TLD.