Richard E. Braunstein

Incidence of visually significant pseudophakic macular edema after uneventful phacoemulsification in patients treated with nepafenac

PURPOSE: To compare the incidence of visually significant pseudophakic macular edema after uneventful phacoemulsification in patients treated postoperatively with topical prednisolone and those treated with topical prednisolone and nepafenac 0.1% suspension (Nevanac). SETTING: Edward S. Harkness Eye Institute of Columbia University, New York, New York, USA. METHODS: This retrospective chart review was of consecutive patients who had phacoemulsification at a single institute and were given topical prednisolone alone or topical prednisolone and nepafenac to prevent cystoid macular edema. Data collection included preexisting ocular and systemic diseases, concurrent use of ocular and systemic medications, surgical technique, intraoperative and postoperative complications, follow‐up visual and ocular assessments, and postoperative optical coherence tomography (OCT) assessment for macular edema. RESULTS: Postoperatively, 240 patients were treated with prednisolone and 210 patients, with prednisolone–nepafenac. Preoperatively, the 2 groups were demographically and clinically comparable in sex distribution (P = .8400), history of diabetes (P = .7267), hypertension or cardiac disease (P = .8690), and concurrent use of oral nonsteroidal anti‐inflammatory drugs (P = .7303). Iris manipulation was done in 16 patients in the prednisolone‐alone group and 10 patients in the prednisolone–nepafenac group (P = .3876). Capsule staining was done in 5 patients and 4 patients, respectively. All patients were followed for at least 1 month postoperatively. Visually significant pseudophakic macular edema was documented by OCT in 5 patients treated with prednisolone alone and in no patients treated with prednisolone and nepafenac (P = .0354). No significant intraoperative or postoperative complications were reported. CONCLUSION: Patients treated with topical prednisolone alone had a significantly higher incidence of visually significant pseudophakic macular edema after uneventful cataract surgery than those treated with topical prednisolone and nepafenac.

Outcome of phacoemulsification after pars plana vitrectomy

PURPOSE To compare the outcome of phacoemulsification surgery in patients with and without prior vitrectomy, adjusted for confounding factors. DESIGN Retrospective cohort study. PARTICIPANTS AND CONTROLS Thirty-one consecutive eyes undergoing phacoemulsification after pars plana vitrectomy (PPV) and 116 consecutive eyes undergoing phacoemulsification without previous PPV. METHODS Office records of the operating surgeons were reviewed for age, gender, type of cataract, vitrectomy status, best-corrected visual acuity (BCVA) before and after phacoemulsification, intraoperative difficulties, and postoperative complications. Bivariate analyses between these predictors and the main outcome, BCVA of 20/40 or better after phacoemulsification, were performed using Pearsons chi-square tests. An adjusted analysis of the relationship between outcome and vitrectomy status was performed with logistic regression. Pearsons chi-square tests were used to compare type of cataract, intraoperative difficulties, and postoperative complications in study and control eyes. MAIN OUTCOME MEASURES BCVA of 20/40 or better after phacoemulsification, rates of intraoperative difficulties, and postoperative complications. RESULTS The most common indication for PPV was macular hole. The average interval from PPV to phacoemulsification was 15.4 months. Study eyes were followed for an average of 10 months compared with 6.6 months for controls. Study eyes were more likely than controls to have predominantly nuclear sclerotic cataracts (P = 0.002). After cataract extraction, 24 of 31 study eyes (77.4%) and 110 of 116 control eyes (94.8%), had BCVAs of 20/40 or better. After adjusting for confounders, eyes without previous vitrectomy were 3.44 times more likely to obtain a BCVA of 20/40 or better than eyes with prior PPV, but this difference was not statistically significant (95% CI, 0.72-16.67). Only 3 of 31 (9.7%) study and 11 of 116 (9.4%) control eyes had intraoperative difficulties (P = 0.47). Posterior capsule plaque was the most common intraoperative difficulty in study eyes; small pupil requiring stretching or iris hooks was most common in controls. Only 1 of 31 (3.2%) study eyes had a postoperative complication other than posterior capsule opacification compared with 18 of 116 (15.5%) controls (P = 0.07). CONCLUSIONS A large proportion of patients with prior PPV obtain good visual acuity after phacoemulsification. We did not find significantly higher rates of intraoperative difficulties or postoperative complications compared with controls. The benefits of phacoemulsification seem to be limited only by retinal comorbidity.

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.

Evaluation of Lenticonus in Alport’s Syndrome: Quantitative Scheimpflug Analysis

Anterior lenticonus is an ocular abnormality that can occur in Alport’s syndrome. In this study, Scheimpflug slit imaging analyses were employed for quantitative and objective evaluation of lens changes associated with Alport’s syndrome. It was determined that while the apices of the lenticular protrusions are central in the vertical plane, they are nasally displaced in the horizontal meridian. The eccentricity and dimensions of the diameters and thicknesses of the conical aberration are highly correlated in both eyes. Lens thickness and anterior chamber depth do not differ between eyes. Densitometrically similar differences are apparent in the cortex and nuclear regions although evidence of overt opacification may or may not be present. The data strongly suggest that the physical parameters of the lenticonus are consistent with the constraints imposed by the pupil. Changes observed in the cornea and the vitreous may be associated with the syndrome.

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.

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.

Effects of mitomycin C on infiltration of polymorphonuclear leukocytes after epithelial scrape injury in the mouse cornea

PURPOSE To determine whether mitomycin C (MMC) alters appearance and disappearance of polymorphonuclear leucocytes (PMN) in the cornea stroma, using an epithelial scrape injury in eye mouse model. METHODS Twenty-mice underwent mechanical epithelium debridement in the central cornea using 20% ethanol. After the scrape, the right eye received 0.02% MMC for one minute, while the left eye received physiological saline. The animals were sacrificed on days 1, 2, 5, and 14 after surgery, and corneal whole mounts were prepared for histology. PMN distribution was analyzed in digitized microscope images. Cell division in the cornea was determined by immunohistochemical detection of bromodeoxyuridine (BrdU), which was injected intraperitoneally before the mice were sacrificed. RESULTS Epithelial scrape injury triggered infiltration of PMNs into the corneal stroma. An analysis of PMN distribution revealed that there was no difference between eyes treated with and without MMC at all time points. BrdU labeling showed that 0.02% MMC for one minute blocked keratocyte proliferation completely. CONCLUSION MMC treatment regimen, which is common in clinical practice, inhibits keratocyte proliferation during wound healing, but when used at 0.02% for one minute, it does not affect PMN infiltration into the corneal stroma, and subsequent movement toward the injury site, or the disappearance of PMNs from the stroma, in the mouse epithelial injury model.