Corneal edema and decreased endothelial cell count are complications related to chronic low-grade hypoxia experienced by contact lens wearers, primarily due to prolonged and overnight wear. This case shows the example of a patient who has blurred vision problems in both eyes and who underwent a complete ophthalmologic examination that included photographs, corneal topography and endothelial cell count. Subsequently, the corneal metabolism, the etiopathogenesis and the complications derived from the use of contact lenses are reviewed.

OBJECTIVE: To describe intracameral toxic effects of cefuroxime at a higher dose than recommended in cataract surgery.
METHODS: Retrospective study of 8 eyes of 8 patients who inadvertently received 12.5 mg/0.1 ml of intracameral cefuroxime due to a dilution error, at the end of the cataract surgery. All patients underwent a strict ophthalmology follow-up for 6 months.
RESULTS: All patients presented with a marked anterior segment inflammation with corneal oedema that resolved completely in all cases (between 5 days and 3 months). At 6 months of follow-up a statistically significant difference was found in the corneal endothelial cell density when compared with the fellow eye (P = .038), being <1000 cells/mm2 in 3 cases. Three patients (37.5%) showed early macular oedema, with subfoveal ellipsoid layer disruption in one case as a permanent sequel. One patient developed an optic neuropathy with associated afferent pupillary defect.
CONCLUSIONS: Although 1 mg/0.1 ml of intracameral cefuroxime has been shown to reduce the incidence of endophthalmitis, its overdose can have potentially toxic eye effects in both anterior and posterior segments.

OBJECTIVE: To describe intracameral toxic effects of cefuroxime at a higher dose than recommended in cataract surgery.
METHODS: Retrospective study of 8 eyes of 8 patients who inadvertently received 12.5mg/0.1ml of intracameral cefuroxime due to a dilution error, at the end of the cataract surgery. All patients underwent a strict ophthalmology follow-up for 6 months.
RESULTS: All patients presented with a marked anterior segment inflammation with corneal oedema that resolved completely in all cases (between 5 days and 3 months). At 6 months of follow-up a statistically significant difference was found in the corneal endothelial cell density when compared with the fellow eye (P=.038), being<1000 cells/mm2 in 3 cases. Three patients (37.5%) showed early macular oedema, with subfoveal ellipsoid layer disruption in one case as a permanent sequel. One patient developed an optic neuropathy with associated afferent pupillary defect.
CONCLUSIONS: Although 1mg/0.1ml of intracameral cefuroxime has been shown to reduce the incidence of endophthalmitis, its overdose can have potentially toxic eye effects in both anterior and posterior segments.

METHODS: A 70 year-old male patient with a history of radial keratotomy suffering from Fuchs\' dystrophy and a cataract. The patient received a two-step surgery: lens phacoemulsification and intraocular lens implant, followed by descemet stripping automated endothelial keratoplasty in both eyes, four months later. There were no complications apart from a recurrent cystoid macular oedema in both eyes. The best corrected visual acuity was 20/40 both eyes, and the patient was satisfied.
CONCLUSIONS: Descemet stripping automated endothelial keratoplasty may be considered as an alternative to penetrating keratoplasty in the case of endothelial dysfunction and radial keratotomy in patients with no corneal ectasia or significant stromal opacity.

METHODS: A middle-aged adult male was referred to our institution due to unilateral corneal edema for a possible corneal transplant. At first, the patient denied a history of trauma. A small foreign body, which had been overlooked by the primary ophthalmologist, was detected by gonioscopy, embedded in the anterior chamber angle. It was successfully surgically removed and visual results were good.
CONCLUSIONS: In any patient with unilateral unexplained corneal edema, it is necessary to rule out the presence of a foreign body in the anterior chamber.

OBJECTIVE: To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers.
METHODS: Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking.
RESULTS: For the +6.00 D and -10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the -10.00 and -3.00 D (Re-ANOVA, p<0.001), (7.7±2.9% vs. 6.8±2.8% and 6.5±2.5% respectively) but there was no difference between -10.00 and -3.00 D. Averaged for power, lotrafilcon A induced the least (6.2±2.8%) and galyfilcon A the most (7.6±3.0%) swelling at the center (Re-ANOVA, p<0.001). Central corneal swelling with +6.00 D was significantly greater than -10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers.
CONCLUSIONS: The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility.