Journal of Ophthalmic and Vision Research
Volume:6 Issue: 1, Jan-Mar 2011

To introduce a specular microscopic reference image for endothelial vacuolation in donated corneas. Two corneas from a donor with diffuse, round to oval dark areas at the endothelial level on slit lamp biomicroscopy and one normal-appearing donor cornea underwent specular microscopy, histopathologic evaluation and transmission electron microscopy. Specular microscopy of the two corneas with abnormal-looking endothelium revealed large numbers of dark, round to oval structures within the endothelium in favor of endothelial vacuolation. Light microscopy disclosed variable sized cyst-like structures within the cytoplasm. Transmission electron microscopy showed electron-lucent and relatively large-sized intracytoplasmic vacuoles. These features were not observed in the endothelium of the normal cornea. The specular microscopic features of endothelial vacuolation in donated corneas were confirmed by light microscopy and transmission electron microscopy, therefore the specular image may be proposed as a reference to eye banks.

To evaluate short-term changes in central corneal endothelial cell density and morphology after photorefractive keratectomy (PRK) with mitomycin-C (MMC) 0.02% in patients with moderate myopia. In this prospective interventional case series, patients with moderate myopia (spherical equivalent refractive error from 4.0 to 8.0 D) underwent PRK with a single intraoperative application of MMC 0.02% for 40 seconds. Specular microscopy was performed preoperatively and repeated 6 months after surgery to determine changes in central corneal endothelial cell density (ECD), mean cell area (MCA) and coefficient of variation in cell size (CV). Overall, 42 eyes of 21 participants with mean age of 26.2±6.3 years underwent surgery. Mean preoperative spherical equivalent refractive error was 5.2±1.2 D which was reduced to 0.4±0.5 D postoperatively (P < 0.001). Mean ECD was reduced insignificantly from 2,920±363 cells/mm2 preoperatively to 2,802±339 cells/mm2 postoperatively (P = 0.59). Similarly, there was no significant change in MCA or CV at six months (P = 0.76 and 0.52, respectively). Application of MMC 0.02% for 40 seconds during PRK in patients with moderate myopia did not significantly affect central corneal endothelial cell density and morphology after a 6 month follow up period.

To assess the relationship between corneal endothelial cell loss after phacoemulsification and the location of the clear corneal incision. A total of 92 patients (92 eyes) with senile cataracts who met the study criteria were included in this cross sectional study and underwent phacoemulsification. The incision site was determined based on the steep corneal meridian according to preoperative keratometry. Endothelial cell density was measured using specular microscopy in the center and 3 mm from the center of the cornea in the meridian of the incisions (temporal, superior, and superotemporal). Phacoemulsification was performed by a single surgeon using the phaco chop technique through a 3.2 mm clear cornea incision. Endothelial cell loss (ECL) was evaluated 1 week, and 1 and 3 months postoperatively. At all time points during follow-up, ECL was comparable among the 3 incision sites, both in the central cornea and in the meridian of the incision (P > 0.05 for all comparisons). However, 3 months postoperatively, mean central ECL with superior incisions and mean sectoral ECL with temporal incisions were slightly higher. Superotemporal incisions entailed slightly less ECL than the other 2 groups. Overall, one month after surgery, mean central ECL was 10.8% and mean ECL in the sector of the incisions was 14.0%. Axial length and effective phaco time (EFT) were independent predictors of postoperative central ECL (P values 0.005 and < 0.0001, respectively). A superotemporal phacoemulsification incision may entail less ECL as compared to other incisions (although not significantly different). The amount of central ECL may be less marked in patients with longer axial lengths and with procedures utilizing less EFT.

To report corneal epithelial defects (CEDs) and delayed epithelial healing after intravitreal bevacizumab (IVB) injection and to describe delayed corneal epithelial healing with topical administration of bevacizumab in an experimental rabbit model. A retrospective chart review was performed on 850 eyes of 850 patients with neovascular eye disease and diabetic macular edema who had received 1.25 to 2.5 mg IVB. In the experimental arm of the study, photorefractive keratectomy was used to create a 3 mm CED in the right eyes of 18 New Zealand rabbits which were then randomized to three equal groups. All rabbits received topical antibiotics, additionally those in group A received topical bevacizumab and animals in group B were treated with topical corticosteroids. The rate of epithelial healing was assessed at different time points using slitlamp photography. In the clinical study, seven eyes of seven subjects developed CEDs the day after IVB injection. All of these eyes had preexisting corneal edema. The healing period ranged from 3 to 38 days (average 11 days) despite appropriate medical management. In the experimental study, topical bevacizumab and corticosteroids both significantly hindered corneal epithelial healing at 12 and 24 hours. Bevacizumab was demonstrated to cause CEDs in clinical settings. Moreover, corneal epithelial healing was delayed by topical application of bevacizumab, in the experimental model. These short-term results suggest that corneal edema may be considered as a risk factor for epithelial defects after IVB.

To determine the effect of cataract type and severity in eyes with pure types of age-related lens opacities on visual acuity (VA) and contrast sensitivity in the presence and absence of glare conditions. Sixty patients with senile cataracts aged 40 years or older with no other ocular pathologies were evaluated for VA and contrast sensitivity with and without glare. Lens opacities were classified according to the Lens Opacities Classification System (LOCS) III. VA was measured using the Snellen chart. Contrast sensitivity was measured with the Vector Vision CSV-1000E chart in the presence and absence of glare by calculating the area under log contrast sensitivity (log CS) function (AULCSF). Cataracts were posterior subcapsular in 26 eyes, cortical in 19 eyes and nuclear in 15 eyes. VA significantly decreased with increasing cataract severity and there was significant loss of contrast sensitivity at all spatial frequencies with increasing cataract severity. AULCSF significantly decreased with increasing cataract severity in the presence and absence of glare conditions. Contrast sensitivity was significantly reduced at high spatial frequency (18 cpd) in cortical cataracts in the presence of glare in day light and at low spatial frequency (3 cpd) in night light. Increased cataract severity is strongly associated with a decrease in both VA and AULCSF. Contrast sensitivity scores may offer additional information over standard VA tests in patients with early age-related cataracts.

To assess the prevalence of presenting visual impairment and refractive errors on the isolated island of Tau, American Samoa. Presenting visual acuity and refractive errors of 124 adults over 40 years of age (55 male and 69 female) were measured using the Snellen chart and an autorefractometer. This sample represented over 50% of the island's eligible population. In this survey, all presenting visual acuity (VA) was uncorrected. Of the included sample, 10.5% presented with visual impairment (visual acuity lower than 6/18, but equal to or better than 3/60 in the better eye) and 4.8% presented with VA worse than 6/60 in the better eye. Overall, 4.0% of subjects presented with hyperopia (+3 D or more), 3.2% were myopic (1 D or less), and 0.8% presented with high myopia (5 D or less). There was no significant difference between genders in terms of visual impairment or refractive errors. This study represents the first population-based survey on presenting visual acuity and refractive errors in American Samoa. In addition to providing baseline data on vision and refractive errors, we found that the prevalence of myopia and hyperopia was much lower than expected.

Most pathological processes involve complex molecular pathways that can only be modified or blocked by a combination of medications. Combination therapy has become a common practice in medicine. In ophthalmology, this approach has been used effectively to treat bacterial, fungal, proliferative/neoplastic, and inflammatory eye diseases and vascular proliferation. Combination therapy also encompasses the synergistic effect of electromagnetic radiation and medications. However, combination therapy can augment inherent complications of individual interventions, therefore vigilance is required. Complications of combination therapy include potential incompatibility among compounds and tissue toxicity. Understanding these effects will assist the ophthalmologist in his decision to maximize the benefits of combination therapy while avoiding an unfavorable outcome.

To report a case of non-Hodgkin’s lymphoma (NHL) presenting as an ocular adnexal and forehead mass. CASE REPORT: An elderly male patient was referred by a neurosurgeon to the eye clinic with a six-month history of a massive tumor measuring 12x16x8 cm involving the right side of the forehead, eyebrow and upper eyelid. Neurological examination had been normal and computed tomography revealed no intracranial extension. The patient was referred to an otorhinolaryngologist who performed an incisional biopsy which revealed the mass to be NHL. He received chemotherapy with CHOP regimen (cyclophosphamide, adriamycin, vincristine and prednisolone) resulting in reduction in lesion size leaving a phthysical eyeball and a ptotic lid. Non-Hodgkin’s lymphoma may occur in almost any part of the body and should be considered in the differential diagnosis of extralymphoid tumors.

To report a case of spontaneous direct carotid-cavernous fistula causing abrupt loss of vision. CASE REPORT: A 50-year-old woman with systemic hypertension but no history of ocular disease developed sudden proptosis, frozen eye, subconjunctival hemorrhage and loss of vision in her left eye over 2 hours. Imaging studies revealed a direct carotid-cavernous fistula. Management for high intraocular pressure was promptly initiated and the patient was referred to a neurosurgery service, but she refused any surgical intervention. Ultimately, she accepted to undergo manual carotid artery compression which resulted in significant reduction in the proptosis, but she lost all vision permanently. Direct carotid-cavernous fistula can occur spontaneously and should be taken into account in patients with signs suggestive of direct carotid-cavernous sinus fistula even without history of trauma or connective tissue disorder.

Herein we describe a technique for management of large inadvertent full-thickness trephination during deep anterior lamellar keratoplasty using the big-bubble technique without converting to penetrating keratoplasty. First, the anterior chamber is formed with an ophthalmic viscosurgical device (OVD). Then, the full-thickness wound is secured with one X-type 10-0 nylon suture. A 27-gauge needle is attached to a 2 ml air-filled syringe and inserted into the corneal stroma in the meridian opposite to the site of full-thickness trephination. Air is gently injected to produce a limited area of "big-bubble" detaching Descemet's membrane (DM) from the corneal stroma. The "big bubble" is slowly expanded with injection of OVD. Finally, the recipient stroma is removed, the donor lenticule is placed and the DM tear is secured with one full thickness 10-0 nylon suture.