[Effects of encircling scleral buckling on the morphology and biomechanical properties of the cornea]. / Efecto del cerclaje escleral en la cirugía vítreo-retiniana sobre la morfología y biomecánica de la córnea.

OBJECTIVE: To investigate the effects of encircling scleral buckle (SB) on corneal biomechanical properties of the cornea and its morphological parameters. METHODS: We prospectively examined twelve eyes diagnosed with vitreous haemorrhage undergoing pars plana vitrectomy (PPV), and fifteen eyes undergoing combined PPV and scleral buckle (PPV/SB) for repair of rhegmatogenous retinal detachment (RRD). Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF), were measured with an Ocular Response Analyser (ORA) before and 1-month postoperatively. The ORA also determined the values of intraocular pressure (IOPg) and corneal compensated IOP (IOPcc). Finally, four morphological parameters of the cornea were measured with the Orbscan II topographer (Orbtek, Inc.): mean corneal power, thinnest corneal point (µm), and anterior chamber depth (ACD). RESULTS: CH decreased significantly from 10.2+/-1.7mmHg to 7.6+/-1.1mmHg after PPV/SB (p=0.003), but not after PPV alone (9.8+/-3.2mmHg vs 11.6+/-2.7mmHg, P=.465). CRF did not change significantly after surgery in both groups. IOPg and IOPcc increased significantly in the PPV/SB group (P=.019 and P=.010, respectively) but not in PPV group (P=.715 and P=.273, respectively). Unlike the PPV group, values were significantly higher than IOPg values before (P=.001) and after surgery (P=.003) in the PPV/SB group IOPcc. Neither the PPV/SB group nor the PPV group showed any significant changes in the corneal morphological parameters after surgery (P>.05). CONCLUSIONS: SB surgery leads to a change in the corneal biomechanical properties without altering corneal morphological parameters. It may cause an underestimation error in IOP measurement. PPV may be a less invasive surgical approach for the repair of noncomplex RRD than PPV/SB.

[Eyelid contact allergic eczema caused by topical ketorolac tromethamine 0.5%]. / Eccema alérgico de contacto palpebral por ketorolaco trometamol 0,5% tópico.

CLINICAL CASE: A 65-year-old man had been treated with eye-drops containing NSAIDs (Ketorolac). He developed conjunctival injection, edematous swelling of the eyelids and periorbital dermatitis due to a contact allergy. Allergy to NSAIDs is uncommon. DISCUSSION: This is an unusual case because topical application of ketorolac is safe in the vast majority of ophthalmologic patients. However adverse events associated with Ketorolac are similar to that of other NSAIDs.

Posttraumatic reaction in a case of fundus flavimaculatus with atrophic macular degeneration.

We report the case of a 13-year-old girl who had fundus flavimaculatus with atrophic macular degeneration. At the age of 14 years, she suffered mild trauma OD, subsequently developing a fibroglial reaction of the retina and pigmentary migration. The coexistence of both phenomena could be explained by the liberation of growth factors by the damaged retinal pigment epithelial (RPE) cells as a reaction to the injury and/or by the passage of chemoattractants from the serum through the damaged RPE cell barrier.

Noonan's syndrome with keratoconus and optic disc coloboma.

We report the case of a 14-year-old girl with multiple findings characteristic of Noonan's syndrome, including short stature, mild mental retardation, facial, skeletal and renal abnormalities. In addition, ophthalmic examination revealed a keratoconus in the left eye and a right optic disc coloboma. To date, only two cases of Noonan's syndrome with keratoconus have been reported, and this is the second case of this syndrome with optic disc coloboma. To our knowledge, this is the first report of Noonan's syndrome associated with unilateral keratoconus and contralateral optic disc coloboma. In view of the large number of patients with Noonan's syndrome reported to date and the rarity of these ocular abnormalities, it is most likely that this association is fortuitous. Ocular findings reported in patients with Noonan's syndrome are reviewed.

Levels of vancomycin in aqueous humor after topical eye drops administration.

Vancomycin is an antibiotic which is especially active against Gram positive bacteria. At present, numerous infections of the anterior segment of the eye are caused by the Staphilococcus aureus and epidermis. Strains which are resistant to methicilin are more and more frequent and for this reason Vancomycin is becoming the antibiotic of choice to combat these infections since no resistance of the Staphilococcus to it has been demonstrated. The authors evaluated the levels of Vancomycin in aqueous humor after the administration of topical eye-drops. For the first two hours after the last administration, levels of 0.52 micrograms/ml were detected. These inhibit the growth of the majority of bacteria sensitive to Vancomycin. Between two and four hours, the levels decreased to 0.15 micrograms/ml; these are therapeutic levels for a large number of Gram positive bacteria. From four hours after the last administration, these levels are undetectable. Due to the success of its penetration, topical administration of Vancomycin should be considered as a therapeutic modality against infections by gram positive bacteria of the anterior segment. The ideal guideline for administration would be one drop every two hours, especially if the infection is severe. In this way, subconjunctival injection could be avoided.