Intraocular pressure after myopic laser refractive surgery measured with a new Goldmann convex prism: correlations with GAT and ORA.

BACKGROUND: The purpose of this study is to describe measurements using a newly developed modified Goldmann convex tonometer (CT) 1 year after myopic laser refractive surgery. Intraocular pressure (IOP) measurements were compared with IOP values obtained by Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA). METHODS: Prospective double-masked study performed on thirty eyes of thirty patients that underwent laser in situ keratomileusis (LASIK; n = 19) or photorefractive keratectomy (PRK; n = 11). IOP was measured before and 3 and 12 months after surgery. Intraclass correlation coefficient (ICC) and Bland-Altman plot were calculated to assess the agreement between GAT, CT, IOPg (Goldmann-correlated IOP) and IOPcc (corneal-compensated IOP) from ORA. RESULTS: Twelve months after LASIK, IOP measured with CT showed the best correlation with IOP measured with GAT before surgery (GATpre) (ICC = 0.886, 95% CI: 0.703-0.956) (15.60 ± 3.27 vs 15.80 ± 3.22; p < 0.000). However, a moderate correlation was found for IOP measured with IOPcc and CT 12 months after LASIK (ICC = 0.568, 95% CI: - 0.185 - 0.843) (15.80 ± 3.22 vs 12.87 ± 2.77; p < 0.004). Twelve months after PRK, CT showed a weak correlation (ICC = - 0.266, 95% CI: - 3.896 - 0.663), compared to GATpre (17.30 ± 3.47 vs 16.01 ± 1.45; p < 0.642), as well as poor correlation (ICC = 0.256, 95% CI: - 0.332 - 0.719) with IOPcc (17.30 ± 3.47 vs 13.38 ± 1.65; p < 0.182). CONCLUSIONS: Twelve months after LASIK, IOP measured with CT strongly correlated with GAT before surgery and could therefore provide an alternative method for measuring IOP after this surgery. More studies regarding this new convex prism are needed to assess its accuracy.

REVERSIBLE BILATERAL SUBFOVEAL ELLIPSOID ZONE FOCAL THICKENING ASSOCIATED WITH OVERDOSE OF PHOSPHODIESTERASE TYPE 5 INHIBITORS INTAKE.

PURPOSE: To describe the clinical findings and outcome of an unusual case of subfoveal yellowish deposits associated with excessive doses of phosphodiesterase Type 5 inhibitors intake. METHODS: Single retrospective case report. RESULTS: A 50-year-old South American man with a personal history of multiple orally administered phosphodiesterase Type 5 inhibitors drugs to treat a chronic erectile dysfunction complained of dyschromatopsia, photophobia, and a 3-month history of blurred vision. The fundus examination revealed a symmetrical yellowish lesion in both eyes with a subfoveal hyperreflective signal on the spectral domain optical coherence tomography at the level of the ellipsoid zone. Dysregulation of the blue-yellow axis was noticed in the color vision test and the electroretinogram demonstrated a tiny decrease in the b-wave amplitude. The use of phosphodiesterase Type 5 inhibitors was discontinued and the patient was examined 3 months later. Optical coherence tomography revealed complete disappearance of the deposit in both eyes and the associated symptoms resolved rapidly with discontinuation of the drug. CONCLUSION: A bilateral ellipsoid zone subfoveal focal thickening may be related to a yellowish symmetrical spot on the fovea in patients with a history of phosphodiesterase Type 5 inhibitors overdose intake. Functional and structural findings are reversible in a short-term period after discontinuing the oral treatment.

New applanation tonometer for myopic patients after laser refractive surgery.

This study assesses the agreement between intraocular pressure (IOP) measurements taken with the Goldmann applanation tonometer (GAT) and a new experimental applanation tonometer with a convexly shaped apex (CT) after laser myopic refractive surgery. Two different CT radii (CT1 and CT2) were designed with a finite element analyser, and a prospective double masked study on 102 eyes from 102 patients was carried out. A Bland-Altman plot and intra-class correlation coefficient (ICC) were calculated to assess the agreement between GAT measurements and the measurements of both CT1 and CT2 before and after myopic laser assisted in situ keratomileusis (LASIK; n = 73) and photorefractive keratectomy (PRK; n = 29). We evaluated a subset of two subgroups (n = 36 each) for intra and inter-observer (IA/IE) error. From the whole cohort, the best IOP agreement was observed between GATpre and CT1post surgery: 16.09 ± 2.92 vs 16.42 ± 2.87 (p < 0.001); ICC = 0.675 (95% CI: 0.554-0.768). In the analysis of LASIK vs PRK, GATpre and CT1post showed the highest agreement, although LASIK measurements were more accurate than PRK, as the ICC = 0.718 (95% CI: 0.594-0.812) and ICC = 0.578 (95% CI: 0.182-0.795) respectively. Excellent agreement was observed for IA/IE, and there was an ICC > 0.8 (95% CI) in all cases. CT1 proved more accurate in the LASIK subgroup. In conclusion, our new version of GAT could be used with post-surgery LASIK patients as a more accurate measurement device compared to the current reference tonometer.

Methicillin-Resistant Staphylococcus aureus Acute Keratitis After Intracorneal Ring Segment Implantation.

INTRODUCTION: The purpose of this study was to report the first case of acute bacterial keratitis produced by methicillin-resistant Staphylococcus aureus after the implantation of two intracorneal ring segments during an uneventful procedure for treating keratoconus in a 13-year-old child. CASE REPORT: A patient with grade III keratoconus underwent an implantation of intracorneal ring segments with no complications during the procedure. Three days later, a whitish corneal infiltrate appeared in between the union of both corneal rings. Sample cultures were positive for methicillin-resistant S. aureus (MRSA). Corneal infiltrate did not improve despite intensive topical and systemic antibiotics. Melting appeared even after the explantation of both corneal rings. Keratoplasty à chaud had to be performed to preserve the eye integrity. CONCLUSIONS: MRSA keratitis following intracorneal ring segment implantation is a rare but severe complication that can lead to a therapeutic penetrating keratoplasty to definitely cure the process.