Suzanna Airiani

Cataract surgery results after pars plana vitrectomy.

&NA; Continuous refinements in vitreoretinal surgical techniques and an increasing number of posterior segment disorders are being successfully managed with pars plana vitrectomy (PPV). This has resulted in an increase in the number of vitrectomized eyes seen by cataract surgeons. Cataract surgery in previously vitrectomized eyes has been reported to be more challenging than in eyes without previous vitrectomy. Special considerations and precautions are often required before, during, and after the surgery to successfully address these challenges. Several studies have reported that phacoemulsification with intraocular lens implantation after PPV is a relatively safe procedure that can improve visual acuity and quality of life. The extent of visual improvement may be limited only by retinal comorbidity.

Corneal edema resolution after descemetorhexis

A 79-year-old woman had left eye phacoemulsification complicated by inadvertent excision of Descemets membrane (DM). One day postoperatively, the visual acuity was counting fingers with diffuse corneal edema. The patient was treated medically, with gradual resolution of the corneal edema over a 6-month period. The torn edge of DM could be visualized as the edema cleared, and no endothelial cell count could be obtained centrally. Approximately 1 year postoperatively, the central endothelial cell count was 2114 cells/mm(2) in the right eye and 827 cells/mm(2) in the left eye. The decreased cell count, increased polymegethism, and pleomorphism suggested that endothelial cells migrated to cover the stromal surface area in the absence of DM.

Initial Studies Using Aliphatic β-Nitro Alcohols for Therapeutic Corneal Cross-Linking

PURPOSE Corneal collagen cross-linking through UVA-riboflavin photochemistry (UVAR) has been shown to be an effective treatment for keratoconus and related keratectasias. In recent studies using sclera, the authors observed that short-chain aliphatic beta-nitro alcohols can cross-link collagenous tissue under physiologic conditions. Thus, this study was undertaken to evaluate these agents as potential pharmacologic alternatives to UVAR. METHODS Porcine corneal strips (8 x 4 mm) and corneoscleral complexes were cross-linked using 1 to 100 mM 2-nitroethanol (2ne), 2-nitro-1-propanol (2nprop), and 3-nitro-2-pentanol (3n2pent) at pH 7.4, 34 degrees C. Cross-linking by UVAR was carried out for comparison. Thermal shrinkage temperature analysis was used to evaluate cross-linking effects, and changes in corneal light transmission were determined with a fiber-optic spectrophotometer. RESULTS At 10 and 100 mM for 96 hours, initial shrinkage temperature (T(i)) was shifted by 3.3 degrees C (P < 0.001) and 9.8 degrees C (P < 0.001) for 2ne, 2.9 degrees C (P = 0.008) and 4.9 degrees C (P < 0.001) for 2nprop, and 3.8 degrees C (P = 0.003) and 4.9 degrees C (P < 0.001) for 3n2pent. Reacting at 1 mM through daily exchange of fluid over 7 days shifted T(i) by 3.8 degrees C (P < 0.001), 4.4 degrees C (P = 0.002), and 3.2 degrees C (P = 0.005), for 2ne, 2nprop, and 3n2pent, respectively. These shifts were greater than cross-linking using UVAR (T(i) = 1.9 degrees C; P = 0.012). In the blue light region (400-500 nm), transmission was decreased by 5.6% (P = 0.003), 2.1% (P = 0.260), and 0% (P = 0.428) for 2ne, 2nprop, and 3n2pent, respectively. CONCLUSIONS beta-Nitro alcohols can induce corneal cross-linking in vitro better than the UVAR technique and can induce negligible effects on light transmission. These early results suggest that such compounds could be used as topical stiffening agents for keratoconus and related disorders.

Aliphatic β-nitro alcohols for non-enzymatic collagen cross-linking of scleral tissue

The success of riboflavin photochemical cross-linking of the cornea in treating keratoconus and post-surgical keratectasia has prompted interest in cross-linking scleral tissue with a potential application to stabilize myopic progression. Applying an UVA light source to the sclera is difficult, particularly in the posterior region. An alternate pharmacologic approach to scleral cross-linking may be possible. The present study was undertaken in order to identify nitrite related compounds capable of inducing scleral tissue cross-linking and to gain information regarding the possible chemical mechanisms involved. 8x4 mm strips of porcine and human sclera were incubated in various concentrations of nitrite related agents (1-100mM) at 37 degrees C. pH 7.4 was used for all experiments except those involving NaNO(2). Following a 24-96 h incubation period, the samples were tested for cross-linking effects using thermal shrinkage temperature (T(s)) analysis. Several compounds were studied including NaNO(2), 2-nitroethanol, 2-nitro-1-propanol, 3-nitro-2-pentanol, 2-nitrophenol, 2-nitroethane, 2-aminoethanol, isopentyl nitrite, DPTA/NO, DETA/NO, and urea, a nitrous acid trap. The results indicate that short chain aliphatic beta-nitro alcohols (2-nitroethanol, 2-nitro-1-propanol, and 3-nitro-2-pentanol) are particularly effective cross-linking agents at pH 7.4, showing both time and concentration dependent effects. Furthermore, nitrosation does not appear to induce tissue cross-linking. In conclusion, aliphatic beta-nitro alcohols can cross-link scleral tissue at physiologic pH and temperature. Since beta-nitro alcohols are known to have reasonable toxicity profiles, these agents could find utility as pharmacologic cross-linking agents for scleral thinning disease.

The effect of lubricant eye drops on ocular wavefront aberrations.

PURPOSE To study the effect of lubricant eye drop instillation on ocular wavefront aberrations. METHODS The wavefront aberrations of the entire optical path of 30 eyes of 15 patients before and following instillation of lubricant eye drops (Bion Tears; Alcon Laboratories Inc, Ft Worth, Tex) were obtained over a 6-mm pupil using a Hartmann-Shack wavefront sensor (WaveScan; VISX Inc, Santa Clara, Calif). Additional computation of root-mean-square (RMS) errors of higher order aberrations from third to sixth order were done using Zernike Tool Software (VISX Inc). Main outcome measures include the mean changes of total higher order aberrations RMS, higher order aberrations, and point spread function (PSF) of the higher order aberrations. RESULTS The mean changes of total higher order aberrations following instillation of lubricant eye drops on the right eyes were -0.07 microm (95% confidence interval [CI], -0.11 to -0.03) and -0.03 microm on the left eyes (95% CI, -0.07 to 0.01). Significant mean changes were noted for coma and trefoil aberrations with a magnitude of -0.08 microm (95% CI, -0.12 to -0.03) and -0.09 (95% CI, -0.13 to -0.05), respectively, as well as a mean change of the PSF of the higher order aberrations (-0.05 diopters, 95% CI, -0.08 to -0.02) on the right eyes. Although no significant changes in these parameters were demonstrated on the left eyes, a similar trend of changes was observed. CONCLUSIONS Ocular wavefront aberrations may change following eye drop instillation as measured objectively by the WaveScan system. This effect should be taken into consideration in the assessment of patients for wavefront-guided laser vision correction procedures.

Intravitreal injection of tissue plasminogen activator as treatment for an occluded pars plana glaucoma tube

Implanting glaucoma tubes through the pars plana in the setting of a corneal transplant is becoming more common, and there are unique problems associated with such a procedure. A 42-year-old man with multiple previous eye surgeries presented with a nonfunctioning pars plana glaucoma tube. There was no view to the tube tip, but it was presumed to be clogged with fibrin. Intravitreal tissue plasminogen activator (tPA) was injected through the pars plana which resulted in intraocular pressure control without further surgery. This new application of intravitreal tPA has not been reported previously. Future research should investigate the optimal effective and safe dose of intravitreal tPA injection to relieve such occlusions.

Epithelial ingrowth under a laser in situ keratomileusis flap after phacoemulsification

A 47-year-old man was referred to us for management of a cataract in the left eye. The patient had an ocular history of high myopia with anisometropia, amblyopia in the left eye, and stable myopic lattice degeneration in both eyes. The patient had successful bilateral laser in situ keratomileusis 3 years before and multiple retinal surgeries for treatment of a rhegmatogenous retinal detachment associated with a giant retinal tear in the temporal region of the retina with subsequent proliferative vitreoretinopathy. Phacoemulsification was performed uneventfully. A single interrupted 10-0 nylon suture was placed in the temporal clear corneal wound and removed 7 weeks postoperatively. One month later, slitlamp examination revealed a 1.5 mm tongue-like area of epithelial ingrowth under the corneal flap. The epithelial cells seemed to enter the flap-stroma interface through the previously placed suture tract and advanced centrally.

Bilateral circumferential macular folds in inflicted childhood neurotrauma.

PURPOSE To report an infant with inflicted neurotrauma who exhibited bilateral circumferential macular folds. METHODS Bedside ophthalmic examination and fundus photography using RetCam-II (Clarity Medical Systems, Pleasanton, CA). RESULTS Both pupils were miotic and nonreactive. External and anterior segments showed no abnormality. The fundus showed bilateral diffuse multilaminar retinal, subhyaloid, and vitreous hemorrhages. Distinctive macular folds were noted bilaterally. CONCLUSION Circumferential macular folds are most commonly found in abused infants, although it has been suggested that they may be associated with Terson syndrome and severe crush injury.

Benign panretinal uniform radial linear-shaped flecks

Our case illustrates a new presentation of benign retina flecks with line-shaped and panretinal, uniform and radial distribution. Compared with previous reports of fleck retina disorders, our case does not show increased autofluorescence deposits, no delay in dark adaptation, neither significant macular nor nasal disc involvement.1–5 A 51-year-old woman with consanguinous parents was referred for evaluation of bilateral retinal lesions. On examination, best-corrected visual acuity was 6/7.5 with moderate hyperopic correction in both eyes. Visual fields were normal. The anterior segments were unremarkable. Fundus examination revealed multiple yellow-creamy discrete round and mostly linear-shaped flecks scattered throughout the retina in both eyes with relative sparing of the fovea. The flecks distributed in a radial pattern centred around the posterior pole (Fig. 1) and were located well posterior to the retinal vasculature. The discs, maculae and retinal vessels appeared unremarkable. Fundus autofluorescence imaging (cSLO, Heidelberg Retina Angiograph 2; Heidelberg Engineering, Dossenheim, Germany) did not show hyper- or hypofluorescent flecks (Fig. 2a), but multiple discrete round lesions above the retinal pigment epithelium were apparent in the infrared imaging (Fig. 2b). Corresponding spectral optical coherence tomography (Optivue SD-OCT, Fremont, CA, and Cirrus, Carl Zeiss Meditec Inc., Dublin, CA, USA) revealed that these lesions span across the retinal pigment epithelium complex and photoreceptor inner–outer segment junction layers, without involving the choroid (Figs 3,​,4).4). To assess retinal function, ISCEV (International Society for Clinical Electrophysiology of Vision) standardized full-field electroretinography were performed following 20 min and overnight dark adaptation. The electroretinography traces showed that both scotopic and photopic responses were symmetric and within normal limits (Fig. 5). Figure 1 A wide-angle montage of the right (a) and left (b) fundi demonstrates multiple yellow-cream discrete flecks widely distributed in the equator and far periphery of the retina. A few flecks are centred in the posterior pole. Figure 2 (a) Fundus autofluorescence of the right eye showing absence of hyper- or hypofluorescent flecks; (b) infrared imaging of the right eye showing multiple discrete round lesions in the para-foveal area. Figure 3 Spectral-domain OCT of the right eye (Optivue). (a) Multiple flecks in the posterior pole (yellow and green arrows represent OCT scans on (b) and (c), respectively, and white square represents longitudinal SLO scan on (d); (b) normal appearing macula; ... Figure 4 Spectral-domain OCT of the right eye (Cirrus Zeiss). (a) Multiple flecks in the posterior pole (yellow and green arrows represent OCT scans on (b) and (c), respectively, and white square represents longitudinal scan on (d); (b) normal appearing macula; ... Figure 5 Representative photopic and scotopic electroretinogram recordings compared with normal control after 20 min in the right eye and overnight dark adaptation in the left eye. Full-field electroretinographies were performed with Ganzfeld stimulation on this ... In contrast to previous reports,1–3 the retinal lesions in our patient appeared to be significantly smaller, more of a linear shape(s) and uniform in size(s). These lesions were distributed ubiquitously in the equator and mid and far periphery of the fundus. The centrally located flecks in the posterior pole appeared sparse, small, round and dot-like. Unfortunately, the patient’s family members were not available for eye examination. In contrast to the classic findings reported by Audo et al.,4 where the retinal flecks demonstrated increased autofluorescence, the fundus imaging of our patient did not show any specks of abnormal autofluorescence. Infrared imaging (Fig. 2b) and optical coherence tomography (Figs 3,​,4)4) revealed numerous subretinal dot-like lesions, which correspond to those observed in funduscopy. Different types of flecked retinal disorders such as dominant radial drusen, fleck retina of Kandori,1 fundus albipunctatus, retinitis punctata albescens, fundus flavimaculatus and vitamin A deficiency5 may be considered as differential diagnosis. However, the lack of drusen on the nasal side of the optic disc, extension of flecks to peripheral retina, absence of high-density autofluorescent deposits on scanning laser ophthalmoscopy imaging and presence of intact EFEMP1 gene sequence made the diagnosis of dominant radial drusen unlikely. Moreover, normal scotopic electroretinography response excludes fundus albipunctatus. In addition to clinical assessment, electrophysiology testing was essential to exclude fundus albipunctatus and autofluorescent imaging can be a helpful tool to characterize hyper-autofluorescent deposits observed in different variants of benign fleck retina. The normal electrophysiology and visual field testing, in addition to good visual acuity and lack of symptoms justify the condition as benign. Hence, our case represents a different presentation of benign fleck retina,4 with linear-shaped flecks and a panretinal, uniform and radial distribution.