Acanthamoeba keratitis and contact lens disinfecting solutions.

OBJECTIVES: To report cases of culture-proved Acanthamoeba keratitis in Greece over a 10-year period and to evaluate the effectiveness of the commonly used commercial contact lens disinfecting systems in clinical cases of Acanthamoeba keratitis. MATERIAL AND METHODS: During the years 1994-2004, 45 contact lens wearers and 3 non-contact lens wearers presenting with symptoms and signs of keratitis underwent corneal sampling. The scrapings obtained were inoculated directly onto appropriate culture media for bacteria, fungi and Acanthamoeba. All proved positive for Acanthamoeba. The contact lenses and contact lens disinfecting solutions (16 one-step 3% hydrogen peroxide and 3 multipurpose solutions) of 19/45 patients with culture-proven Acanthamoeba keratitis were cultured for bacteria, fungi and Acanthamoeba. RESULTS: Acanthamoeba was isolated from contact lenses and contact lens disinfecting solutions in all 19 cases of Acanthamoeba keratitis studied. CONCLUSIONS: The main risk factor for corneal infection in contact lens wearers is the use of contact lens disinfecting systems ineffective at killing Acanthamoeba cysts and trophozoites, as well as bacteria and fungi. Improvement or development of new contact lens disinfecting systems by manufacturers is needed to prevent Acanthamoeba keratitis.

Arcuate relaxing incisions with a 5.00-mm optical zone for the correction of high postcataract astigmatism.

The purpose of this study was to investigate the efficacy and safety of arcuate cuts with a 5-mm optical zone to correct high postoperative astigmatism after extracapsular cataract extraction. We performed 5-mm optical zone arcuate cuts on 23 eyes of 23 patients with high postoperative astigmatism. Ophthalmic examination included uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA) and the amount of the refractive and keratometric cylinder before and 9 months after operation. Surgically induced refractive change was calculated in all cases. A significant reduction in astigmatism was achieved in all cases with minimal axis deviation. No case developed clinically significant irregular astigmatism. The mean magnitude of astigmatism of the surgically induced refractive change calculated from standard keratometry and refractive data was 3.73+/-0.72 and 3.70+/-0.77 dptr, respectively. The mean axis deviation calculated from the keratometric and refractive data was 1.18+/-2.33 and 1.32+/-3.62 degrees, respectively. At the last examination, 78.2% of the eyes had UCVA of 20/40 or better. No eye lost more than two lines of vision, 6 eyes lost one line, 2 eyes gained one and 1 eye gained two lines of BSCVA. The above data show that the 5-mm optical zone arcuate astigmatic keratotomy is an effective and safe method of correcting high postoperative astigmatism.

Keratoconus and tapetoretinal degeneration.

In a series of 233 keratoconus cases, electroretinograms (ERGs) and visual evoked responses (VERs) were recorded; the results of this study are discussed. In six cases, the ERGs were extinguished, and the VERs were pathologic. In contrast to this, in four cases, ERGs were normal, but VERs were pathologic. Postoperatively the electrophysiologic findings remained the same, and the ophthalmoscopic examination of the eyes revealed the existence of a diffuse tapetoretinal degeneration or a macular lesion. These data show clearly the coexistence in many cases of keratoconus with diffuse tapetoretinal degeneration or macular lesion. The preoperative value of an electrophysiologic study of keratoconus patients is justified to avoid an unneeded corneal transplant.

Clinical experience with cyanoacrylate tissue adhesive.

In this paper 385 cases treated with cyanoacrylate tissue adhesive during the years 1980-1995 are studied. The indications, outcomes and complications of cyanoacrylate adhesive are investigated and the results are analysed. It is encouraging that except for three cases of ocular hypotony and two cases of microbial infection no other complications occurred. Even in desperate cases with corneal perforation greater than 3 mm and ocular infection, enucleation was avoided. The early use of a bandage contact lens, inserted just after the glue application and the coverage with topical antibiotics switched every 15 days until the removal of the glue, may explain the small incidence of infection. Our experience from the use of cyanoacrylate tissue adhesive in cases with corneal perforation greater than 3 mm is very encouraging. In these cases a running 10.0 nylon suture was used to create a reticulum over the space of the corneal perforation upon which the glue was applied. The use of cyanoacrylate tissue adhesive offers to the clinician a safe technique for healing corneal wounds that avoids tectonic penetrating keratoplasty with its associated complications.

Extracapsular cataract extraction in diabetic eyes. The role of YAG laser capsulotomy.

Cataract surgery may exacerbate preexisting diabetic retinopathy. Especially diabetics with active retinal neovascularisation are at high risk of rubeosis iridis after intracapsular cataract extraction. Thirty-five eyes previously treated with panretinal photocoagulation underwent extracapsular cataract extraction with posterior chamber lens implantation. Twenty-eight eyes with retinal neovascularisation required further Argon laser PRP after surgery. Fourteen eyes required YAG-laser capsulotomy. From the group of eyes without YAG-laser capsulotomy none developed neovascular glaucoma. From the YAG laser capsulotomy group six eyes developed rubeosis iridis and neovascular glaucoma. Our results indicate that eyes in which PRP has been performed, have an excellent prognosis after ECCE with posterior chamber lens implantation only if YAG Laser posterior capsulotomy is not performed.

Some observations on the treatment of ischemic optic neuropathy.

We examined the efficacy of the treatment with steroids, vasodilators, and vitamins B1, B6, and B12 in 23 cases of anterior ischemic optic neuropathy treated at the Athens University Eye Clinic. We stress the necessity of an extended medication for 2 to 3 months, depending upon the improvement of visual acuity. Good results were achieved in 14 of the 23 patients.