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Purpose To investigate the natural history and genetic associations of drusenoid pigment epithelial detachment (DPED) associated with age-related macular degeneration (AMD). Design Retrospective analysis of a prospective cohort study. Participants Of the 4203 Age-Related Eye Disease Study 2 (AREDS2) participants, 391 eyes (325 participants) had DPED without late AMD at the time of DPED detection. Genetic analyses included 120 white AREDS2 participants and 145 Age-Related Eye Disease Study (AREDS) participants with DPED. Methods Baseline and annual stereoscopic fundus photographs were graded centrally to detect DPED, a well-defined yellow elevated mound of confluent drusen ≥433 μm in diameter, and to evaluate progression rates to late AMD: geographic atrophy (GA) and neovascular (NV)-AMD. Five single nucleotide polymorphisms (CFH [rs10611670], C3 [rs2230199], CFI [rs10033900], C2/CFB [rs114254831], ARMS2 [rs10490924]) and genetic risk score (GRS) group were investigated for association with DPED development. Kaplan–Meier analyses and multivariable proportional hazard regressions were performed. Main Outcome Measures Progression rates to late AMD and decrease of ≥3 lines in visual acuity (VA) from the time of DPED detection; association of rate of DPED development with genotype. Results Mean (standard deviation [SD]) follow-up time from DPED detection was 4.7 (0.9) years. DPED was associated with increased risk of progression to late AMD (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.98–2.82; P Conclusions This study replicates the results of previous natural history studies of eyes with DPED including the high rates of progression to late AMD and vision loss (regardless of progression to late AMD). The genetic associations are consistent with genes associated with AMD progression.

Purpose To analyze the prevalence, incidence, and clinical characteristics of eyes with geographic atrophy (GA) in age-related macular degeneration (AMD), including clinical and genetic factors affecting enlargement. Design Prospective cohort study within a controlled clinical trial. Participants Age-Related Eye Disease Study 2 (AREDS2) participants, aged 50–85 years. Methods Baseline and annual stereoscopic color fundus photographs were evaluated for GA presence and area. Analyses included GA prevalence and incidence rates, Kaplan-Meier rates, mixed-model regression, and multivariable analysis of the square root of GA, area adjusted for covariates, including clinical/imaging characteristics and genotype. Main Outcome Measures (1) Presence or development of GA; (2) change in the square root of GA area over time. Results At baseline, 517 eyes (6.2%) of 411 participants (9.8%) had pre-existing GA (without neovascular AMD), with the following characteristics: 33% central, 67% noncentral; and the following configurations: 36% small, 26% solid/unifocal, 24% multifocal, 9% horseshoe/ring, and 6% indeterminate. Of the remaining 6530 eyes at risk, 1099 eyes (17.3%) of 883 participants developed incident GA without prior neovascular disease during mean follow-up of 4.4 years. The Kaplan-Meier rate of incident GA was 19% of eyes at 5 years. In eyes with incident GA, 4-year risk of subsequent neovascular AMD was 29%. In eyes with incident noncentral GA, 4-year risk of central involvement was 57%. GA enlargement rate (following square root transformation) was similar in eyes with pre-existing GA (0.29 mm/year; 95% confidence interval 0.27–0.30) and incident GA (0.28 mm/year; 0.27–0.30). In the combined group, GA enlargement was significantly faster with noncentrality, multifocality, intermediate baseline size, and bilateral GA (P Conclusions Analyses of AREDS2 data on natural history of GA provide representative data on GA evolution and enlargement. GA enlargement, which was influenced by lesion features, was relentless, resulting in rapid central vision loss. The genetic variants associated with faster enlargement were partially distinct from those associated with risk of incident GA. These findings are relevant to further investigations of GA pathogenesis and clinical trial planning.

Twenty-five percent of diabetes-related vision loss stems from complications of proliferative diabetic retinopathy (PDR). Panretinal photocoagulation has been the preferred treatment of high-risk PDR for decades and more recently intravitreal injections of drugs that inhibit the actions of vascular endothelial growth factor have become popular. But despite these treatments PDR may progress uncontrollably to advanced pathologies such as traction retinal detachments (TRDs), combined traction/rhegmatogenous retinal detachments (TRD/RRDs), vitreous hemorrhages, rubeosis iridis, and traction maculopathies, which produce mild-to-severe loss of vision. TDR have long been the most common indication for PDR-related vitreoretinal surgery. Vitrectomy surgery is indicated for recent (6 months duration) may also benefit. Combined TRD/RRD represents a particularly challenging surgical condition but advances in surgical instrumentation, dissection techniques, and post-operative tamponade have produced excellent success rates. The recent development of small-gauge vitrectomy systems has persuaded most surgeons to switch platforms since these appear to produce shorter surgical times and quicker post-operative recoveries. Pre-operative injections of bevacizumab are frequently administered for persistent neovascularization to facilitate surgical dissection of pre-retinal fibrosis and reduce the incidence of post-operative hemorrhages. Recent trends toward earlier surgical intervention and expanded indications are likely to continue as surgical instrumentation and techniques are further developed.

David J Browning,1 Chong Lee,1 Michael W Stewart,2 Maurice B Landers III3 1Charlotte Eye, Ear, Nose and Throat Associates, Charlotte, NC, 2Mayo Clinic, Jacksonville, FL, 3Kittner Eye Center, University of North Carolina, Chapel Hill, NC, USA Purpose: To determine the effect of vitrectomy for center-involved diabetic macular edema (CI-DME). Methods: This was a retrospective study of 53 eyes of 45 patients who had vitrectomy for CI-DME and were followed up for at least 12months. Charts were reviewed for visual acuity (VA), central subfield mean thickness measured by optical coherence tomography, presurgical and postsurgical interventions for CI-DME, and number of office visits in the first 12months after surgery. Preoperative spectral domain optical coherence tomography was performed on 38 patients, and they were graded for ellipsoid zone (EZ) intactness by three independent graders with assessment of agreement between graders using intraclass correlation coefficients and Bland–Altman analysis. Results: The median VA improved from 20/100 (interquartile range [IQR], 20/63–20/200) at baseline to 20/63 (IQR, 20/32–20/125) at 12months. The median central subfield mean thickness improved from 505µm (IQR, 389–597µm) at baseline to 279µm (IQR, 246–339µm) at 12months. Intergrader agreement for EZ intactness was moderate (intraclass correlation coefficients 0.4294–0.6356). There was no relationship between preoperative intactness of the EZ and the 12-month change in VA. Conclusion: Vitrectomy consistently thins the macula in CI-DME and, on average, leads to clinically significant improvement in VA comparable in size to that reported with serial intravitreal anti-vascular endothelial growth factor injections. A large, comparative, prospective, randomized clinical trial of these two treatments is needed to determine which is more effective and cost-effective. Keywords: center-involved diabetic macular edema, diabetic macular edema, vitrectomy, spectral domain OCT

To determine the efficacy of vitrectomy in eyes with treatment-naïve diabetic macular edema (DME).Consecutive patients with treatment-naïve DME who underwent pars plana vitrectomy with internal limiting membrane peeling at a single institution were identified from the electronic medical records. Morphologic and visual acuity changes from baseline were analyzed at both the primary temporal endpoint (6 months) and the final examination with the investigators. The primary outcome measures included changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT).Forty-four eyes of 44 patients were included in this retrospective study. The mean BCVA improved significantly from baseline until the 6-month primary endpoint (1.35 logMAR vs 0.83 logMAR, p0.001) and stabilized through the final examination (0.77 logMAR). The BCVA improved by at least 0.1, 0.3, and 0.6 logMAR in 26 (60%), 24 (55%), and 14 (32%) of eyes, respectively, whereas it worsened by 0.3 logMAR in only 1 (2%) eye. Final BCVA correlated inversely with duration of diabetes (p = 0.01), presence of an epiretinal membrane (p = 0.02), and initial visual acuity (p = 0.03). Mean CRT decreased significantly from baseline through 6 months (595 µm vs 266 µm; p0.001), and edema recurred in only 3 eyes (6%), one of which was subsequently treated with intravitreal bevacizumab.Pars plana vitrectomy significantly improves macular edema and visual acuity in eyes with treatment-naïve DME. Prospective randomized trials are needed to better determine the efficacy of early vitrectomy.

Purpose To prospectively assess the effect of neodymium:yttrium-aluminum-garnet peripheral capsulotomy on postvitrectomy hemorrhage in diabetic patients with a posterior chamber intraocular lens (IOL) implant and an intact posterior capsule. Design Interventional case series. Methods This is a prospective case series, clinical practice. Patients Five vitrectomized, diabetic, pseudophakic patients with persistent vitreous cavity hemorrhage remaining after vitrectomy were selected. They all had a posterior chamber IOL implant with an intact posterior capsule. Additionally, they had all undergone laser panretinal photocoagulation in the involved eye in the past for diabetic retinopathy. Neodymium:yttrium-aluminum-garnet laser capsulotomy outside the optic of the IOL was performed in victrectomized diabetic patients to treat the remaining vitreous cavity hemorrhage. Visual acuity, intraocular pressure (IOP), and fundus examination were measured and done immediately after the laser procedure, in 7 days and in approximately 3 months. Results The visual acuity was improved at the time of the first follow-up. However, a mild elevation of IOP was noticed in some patients, which was treated with topical dorzolamide. The final visual acuity was dramatically improved, to 20/30 or better, and the IOP was normalized without medication within a few weeks in all five cases. No neovascularization of the iris or elsewhere was noticed in any case. Conclusions Neodymium:yttrium-aluminum-garnet laser peripheral capsulotomy appears to be a safe and effective management procedure in treating postvitrectomy hemorrhage in diabetic patients who have previously undergone cataract surgery with posterior chamber lens implant, intact posterior capsule, and extensive panretinal photocoagulation. The vitreous hemorrhage cleared completely in all five cases.

Background In some cases of retinopathy of prematurity (ROP), it difficult to determine with certainty whether plus disease is present or absent. We have developed a computer program that captures digital images from a video-indirect ophthalmoscope, identifies and traces the major posterior pole blood vessels, measures the dilation and tortuosity of each vessel, and calculates whether or not an eye has plus disease. Our purpose was to determine the accuracy of the computer program in comparison with two masked examiners. Methods A representative sample of posterior pole images from 20 premature infants, 10 normal and 10 representing various degrees of dilation and tortuosity, was extracted from our video database and analyzed by the computer program as well as by two masked examiners experienced in the diagnosis of ROP. The standard photograph from the Cryotherapy for ROP study, representing the minimum degree of dilation and tortuosity required for plus disease, was also digitized, analyzed, and used as a numeric comparison for the automated determination of plus disease. Results Of the five images determined to have plus disease by both examiners, four were calculated to have plus disease by the computer program (80% sensitivity). Of the 11 images without plus disease, 10 were calculated not to have plus disease by the computer program (91% specificity). Conclusions Our computer program has very good sensitivity and specificity compared with masked examiners’ determination of the presence or absence of plus disease. Automated analysis of dilation and tortuosity of posterior pole blood vessels has the potential to remove subjectivity from the determination of plus disease.

PURPOSE To report two cases of immediate hyphema formation after the intravitreal injection of ranibizumab. METHODS Retrospective case reports. RESULTS A patient with choroidal neovascularization caused by exudative age-related macular degeneration and a patient with cystoid macular edema caused by branch retinal vein occlusion underwent an intravitreal injection of 0.5 mg/0.05 mL of ranibizumab. The development of hyphema was seen immediately after the intravitreal injection in both cases. One patient was pseudophakic, taking 325 mg of aspirin daily. The other patient was phakic without any anticoagulation history. CONCLUSION To the best of our knowledge, this is the third report of the development of hyphema associated with intravitreal injections.

The purpose of this study is to determine baseline vitreous humor temperature during a combined phacoemulsification and pars plana vitrectomy (PPV) procedure; to determine what is the temperature variation during phacoemulsification; and to compare vitreous temperature to sublingual temperature. The methods used are prospective, interventional and comparative study. Patients with a diagnosis of cataract and vitreous hemorrhage, programed for a combined procedure of phacoemulsification and PPV, were included. Patients were excluded if posterior capsular rupture existed during the anterior segment procedure. A thermoprobe was inserted through a PPV trocar. Measurement of the vitreous temperature was obtained at baseline and throughout phacoemulsification, at the end of every surgical step, and every 5 min. Sublingual temperature was measured with the same probe at the end of the surgery. Room temperature was registered. Seventeen eyes of 17 patients were included. Mean sublingual temperature was 36.5 °C (standard deviation [σ] 0.26 °C). Mean total vitreous temperature was 31.47 °C (σ 2.1 °C). Mean baseline vitreous temperature was 33.04 °C (σ 0.99 °C). Comparison of sublingual temperature with baseline vitreous temperature resulted in a significant difference (t test P

To maximize recovery after neurologic injury, physicians use therapeutic hypothermia of 90°F to 93°F (32.2-33.9°C). Temperatures below this are avoided because of increased side effects. The extent to which the retina is cooled during routine vitreous surgery is unknown. This study seeks to describe the temperature changes of the vitreous and retinal surface during vitreous surgery.In this prospective study of 6 patients undergoing vitrectomy, a 23-gauge thermoprobe was used to measure intraocular temperatures before, during, and after vitrectomy.Before vitrectomy, the mean midvitreous temperature was 93.1°F (33.9°C) and retinal temperature was 94.7°F to 95.4°F (34.8-35.2°C). During vitrectomy, the mean midvitreous cavity temperature was 76.9°F (24.9°C) and retinal temperature was 83.2°F to 85.1°F (28.4-29.5°C). After completion of vitrectomy and with a closed infusion line, the mean midvitreous cavity temperature was 87.0°F (30.6°C) and retinal temperature was 90.1°F to 90.9°F (32.3-32.7°C). These changes in temperature before, during, and after vitrectomy were found to be statistically significant.During routine vitreous surgery, the vitreous cavity and retina are cooled to much lower temperatures than those used in therapeutic hypothermia. Rapid rewarming occurs within the eye once the infusion line is closed.

To demonstrate that the Landers wide-field temporary keratoprosthesis (TKP) creates a watertight seal between the tightly opposing surfaces of the TKP flange and the anterior corneal surface.In 25 and 20 enucleated, porcine eyes, a 7.5-mm and 8.0-mm trephination corneal hole was made, respectively, followed by open-sky capsulorhexis and lensectomy. A wide-field TKP with 7.2 mm trunk diameter was sutured securely onto each eye. Testing for a watertight seal was performed at an intraocular pressure of 100 mmHg of pre- and post-pars plana vitrectomy.The Landers TKP maintained a watertight seal at an intraocular pressure of 100 mmHg in 45 of 45 eyes. After standard pars plana vitrectomy, 41 of 41 eyes maintained 100 mmHg of intraocular pressure without leakage.The seal between the TKP and cornea is established at the horizontal interface between the TKP flange and the anterior corneal surface, not between the corneal stroma and TKP trunk. The Landers wide-field TKP is a reusable model that provides a clear posterior-segment view and effectively forms a watertight eye at a sustained intraocular pressure of 100 mmHg. This TKP may be used in ocular trauma where the corneal defect is up to 0.8 mm greater in diameter than the 7.2-mm TKP trunk.

The efficacy of argon and diode laser photocoagulation of the avascular peripheral retina for threshold retinopathy of prematurity (ROP) was compared in a prospective trial. The study group included 9 premature infants (17 eyes). In each infant, one eye was treated with the diode laser indirect ophthalmoscope (LIO), and the fellow eye was treated with the argon LIO. Supplemental oxygen therapy was administered after laser treatment to all nine infants. The mean duration of the follow-up period was 9.7 +/- 2.6 months. All 17 eyes (100%) had complete regression of ROP and favorable outcomes. The diode and argon LIO appear to be equally effective in treating threshold ROP. Two patients sustained burns of the tunica vasculosa lentis and anterior lens capsule in the argon laser treated eye but not in the fellow diode treated eye. Photocoagulation with either the diode or argon LIO, combined with supplemental oxygen treatment, appears to be a promising treatment for retinopathy of prematurity.

The argon laser for diabetic retinopathy therapy was originally selected for photocoagulation by matching peak emission to hemoglobin absorption to maximize obliteration of retinal blood vessels. Present clinical experience in the treatment of diabetic retinopathy does not show any marked advantage of argon lasers over ruby and xenon photocoagulators not matched to hemoglobin absorption. The efficacy of photocoagulation is shown to depend upon the interaction between choroidal and retinal blood supplies in tissue oxygenation and depends upon pigment epithelium absorption to destroy rods and cones. Design specifications for new laser photocoagulators and alternative (supplemental) therapy for diabetic retinopathy are given.

The feasibility of gamma (gamma)-interferon injection for the treatment of ocular fibrotic conditions was studied in rabbits using recombinant rabbit gamma-interferon and the cell-injection model of tractional detachment. A toxicity study revealed that intravitreal injection of greater than 10(4) units gamma-interferon consistently produced panuveitis. For tractional detachment, 250,000 rabbit dermal fibroblasts were injected intravitreally into 20 eyes; 1 day later, 5 of these eyes received intravitreal injections of 10(4) units gamma-interferon, another 5 were given 10(6) units, and the remaining 10 received balanced salt solution. Slit-lamp examination and fundus photography were performed at regular intervals for 21 days and were graded by a masked observer. The eyes were then enucleated and processed for histology. Doses of 10(4) units gamma-interferon significantly reduced the severity of detachments, but injections of 10(6) units induced panuveitis.

To investigate whether there are systemic effects of unilateral intravitreal administration of bevacizumab on the untreated eye.Twenty-three consecutive patients were enrolled in this study. All patients had a clinical diagnosis of bilateral diffuse diabetic macular edema with a central retinal thickness greater than 275 microm by Optical Coherence Tomography. They were treated with 2.5 mg bevacizumab intravitreally in the worst eye based on lines of vision, number of Early Treatment Diabetic Retinopathy Study letters, and central retinal thickness. The patients were observed every 2 weeks for 4 weeks. The Best Corrected Visual Acuity, central retinal thickness (microm), and macular volume (mm) in the untreated eye measured by Optical Coherence Tomography were recorded at every visit.The Best Corrected Visual Acuity (mean +/- SD) in the untreated eye was 34.46 +/- 17.29. Early Treatment Diabetic Retinopathy Study letters at baseline, 38.31 +/- 14.64 at 2 weeks, and 37.38 +/- 14.59 at 4 weeks. The central retinal thickness in the untreated eye was 324.77 +/- 76.51 microm at baseline, 319 +/- 75.7 microm at 2 weeks, and 315.54 +/- 78.2 microm at 4 weeks. The macular volume in the untreated eye was 8.99 +/- 1.2 mm at baseline, 9.16 +/- 1.26 mm at 2 weeks, and 8.99 +/- 1.09 mm at 4 weeks. There were no statistically significant differences between any of the measurements.Due to the lack of significant changes in the measurements of the untreated eye, the systemic effect of intravitreal bevacizumab seems to be unlikely. The small sample and low confidence of this pilot study prevent us to draw concrete conclusions.

An objective method for reliably estimating the width of retinal vessels is presented. A computerized microdensitometer scans film negatives of fundus photographs and reconstructs black and white images of the fundus on a visual display terminal. After this initial scan, a desired region of a retinal vessel is selected with moveable cursors, and a cross-sectional density profile through the vessel is plotted. Vessel width is determined by the half-height width of the profile of the minimum (least transmitting) and average background film densities. Measurement sites can be accurately reproduced on different negatives by landmark mapping. A series of ten fundus photographs were taken of three healthy human eyes, and the width of the superior temporal vein was measured in two places on alle negatives. The coefficient of variation of the six sets ranged from 1.2 and 3.4% with an average of 2.2%.

We describe an ab externo, transscleral, intraocular lens (IOL) fixation technique using a surgeon-fashioned 25-gauge hook, a neodymium:yttrium aluminum garnet (Nd:YAG)-modified 27-gauge needle, and 9-0 polypropylene suture. This is a simple, inexpensive technique for creating small-gauge surgical instruments to accurately and atraumatically pass 9-0 and 10-0 polypropylene sutures through sclera. Holes, through which sutures can be threaded, are "burned" near the tips of 27-gauge or 30-gauge needles with an Nd:YAG laser. Using a fine needle holder, a 25-gauge hook is fashioned from a hypodermic needle. A surgical technique incorporating 2 ab externo incisions and achieving transscleral posterior chamber IOL fixation is discussed.

Purpose To report a new, noncontact wide field viewing system for vitreoretinal surgery. Design Device description: A noncontact wide field viewing system consisting of adjustable hinged arm and a combined condensing lens and reinverting prism has been developed. The arm clamps onto the operating table or wrist rest and holds the lens system in the air above the eye. Methods For vitreoretinal surgery, a new, relatively inexpensive noncontact wide field viewing system consisting of an adjustable hinged arm and a combined condensing lens and reinverting prism has been developed. The combination condensing lens and reinverting prism is used without a microscope–mounted inverter. The optical component may be sterilized with ethylene oxide, peracetic acid, or glutaraldehyde. Other components may be steam autoclaved. Results The new, noncontact wide field viewing system has been used satisfactorily in more than 200 vitrectomies at seven medical centers. It provides an excellent view of the vitreous and retina. Conclusion A new, noncontact wide field viewing system for vitreoretinal surgery has been developed with satisfactory image quality and a field of view comparable to contemporary noncontact panoramic viewing systems.

Purpose To update ophthalmologists on recent developments in the area of antiviral chemoprophylaxis after occupational exposure to human immunodeficiency virus (HIV). Background information is provided by which to make an informed decision about whether to initiate antiviral chemoprophylaxis against HIV infection. Methods We discuss why HIV postexposure prophylaxis should be considered; when prophylaxis should be initiated; where prophylaxis medications should be located in the operating or emergency room; and what medications might be used and the factors influencing their selection. Recent provisional recommendations by the United States Centers for Disease Control and Prevention and the International AIDS Society-USA are reviewed along with literature dealing with antiviral chemoprophylaxis against HIV infection. Results Recommendations are made for specific antiviral chemoprophylaxis after occupational exposure to HIV based on the Centers for Disease Control and Prevention and the International AIDS Society-USA provisional recommendations. Uncertain areas and the minor discrepancies in these two reports are discussed. Conclusions Prevention of HIV transmission after accidental occupational exposure is possible. Combination therapy is more effective than monotherapy in treating HIV infections. Zidovudine (AZT or ZDV) is effective in postexposure prophylaxis; the combination of zidovudine and lamivudine (3TC) and indinavir (IDV) has greater antiretroviral activity than zidovudine alone does. The requirements for effective HIV postexposure prophylaxis may be somewhat different than those for optimum HIV treatment in the chronically ill HIV-positive patient. Ophthalmologists should have an in-depth knowledge of current thinking regarding HIV pathophysiology and treatment.

Purpose To develop a temporary keratoprosthesis with integrated infusion cannula to minimize retinal complications during pars plana vitrectomy in eyes with an opaque cornea. Methods The wide-field temporary keratoprosthesis has been modified to include an integrated infusion cannula. The 20-gauge cannula runs from the periphery of the corneal flange, bends 90 degrees, and enters the eye after passing through the periphery of the corneal cylinder. Results The infusion wide-field temporary keratoprosthesis has been used successfully in three cases without the need to place a separate infusion, which risks iatrogenic retinal breaks or retinal dialyses. Droplet condensation on the posterior surface of the infusion temporary keratoprosthesis was reduced compared with the standard temporary keratoprosthesis. Conclusion We have developed a wide-field temporary keratoprosthesis with an integrated infusion cannula for use during pars plana vitrectomy in eyes with severe corneal opacity. This device eliminates the risk of complications related to the pars plana infusion cannula.

AIMS/BACKGROUND: Human recombinant tissue plasminogen activator (rt-PA) fibrinolysis of subretinal haemorrhage with concomitant removal has been shown to reverse the natural history of photoreceptor degeneration in experimental subretinal haemorrhages if evacuated within 7 days. The aim of the study was to determine whether fibrinolysis of subretinal haemorrhage without concomitant removal would offer a simpler approach with similar photoreceptor sparing. METHODS: A neodymium YAG laser was used to create experimental subretinal haemorrhages beneath the holangiotic retina of the cat. Tissue plasminogen activator (10 micrograms/ml) was injected into 4 day old subretinal haemorrhages to evaluate its effect on altering the natural history of retinal degeneration. Light and electron microscopy were used to study the histopathological effect. RESULTS: The injection of rt-PA into large 4 day old subretinal haemorrhages without concomitant removal did not alter the natural history of retinal degeneration. In fact, a second focus of retinal degeneration occurred at a gravity dependent inferior site where the subretinal haemorrhages had migrated. CONCLUSIONS: There was no therapeutic benefit from the injection of rt-PA into subretinal haemorrhages without con-comitant removal in this cat model.

PURPOSE To assess the optimum probe design and treatment parameters for transscleral diode laser retinopexy. METHODS Transscleral diode photocoagulation was performed on the eyes of Dutch-belted rabbits using three different transscleral probes: a straight, 400-microns diameter probe; a prism-tipped 400-microns diameter probe; and a prism-tipped 900-microns diameter probe. RESULTS Transscleral diode photocoagulation with all three probe types was an effective method of ablating the retina and creating chorioretinal adhesions. Both the burn diameter and the mean radiant output energy requirement increased as the burn duration and probe aperture diameter was increased. Explosive retinal holes were encountered in 12% of the burns created with the straight probe. The use of the prism-tipped probes significantly reduced the incidence of retinal holes to < 4% (P < 0.005). Histopathologically, all burns were grade III in intensity with severe choroidal injury. In many of the burns, there was histopathologic evidence of thermal injury to the inner sclera. The frequency of these inner scleral changes was reduced with a long burn duration (5 seconds). CONCLUSION This study confirms that diode transscleral photocoagulation is a feasible method of thermal retinopexy. The use of the prism-tipped probes and long duration burns resulted in the fewest adverse reactions.

Purpose: To better determine the surgical window for removing experimental subretinal hemorrhages in the cat model and to compare the histopathologic effect of such removal with the natural history of untreated subretinal hemorrhages. Methods: Twenty-three large experimental subretinal hemorrhages were created with a neodymium:YAG laser focused through a preformed retinal bleb in a cohort of cats. Fourteen subretinal hemorrhages were observed without treatment, six were removed at 7 days through a micropipette after injecting 10 μg/ml of human recombinant tissue plasminogen activator (rt-PA) into the subretinal space, and three were removed through an access retinotomy without the use of rt-PA. The tissues from these eyes were examined with light and electron microscopy 14 to 28 days after creation of the subretinal hemorrhages. Results: Severe outer retinal degeneration was evident by day 14 in all of the untreated subretinal hemorrhages 3 disc diameters or greater in size. In contrast, the outer retinal architecture was better preserved in the eyes that underwent rt-PA—assisted removal of their subretinal hemorrhage that was 3 disc diameters or greater on day 7. In these eyes, mild abnormalities such as abnormally short and misaligned photoreceptor outer segments with vacuolization were present within the retina that was formerly located over the hemorrhage center. The eyes that underwent subretinal hemorrhage removal through an access retinotomy without rt-PA on day 7 had a low-lying retinal detachment and outer retinal degeneration. Conclusion: Removing experimental subretinal hemorrhages within 7 days of their occurrence with the assistance of rt-PA and an ultramicrosurgical approach may reduce outer retinal degeneration in the cat model.

Objective To demonstrate the watertight seal created by the new wide-angle Landers trunkless temporary keratoprosthesis (T-TKP). Methods In 20 enucleated, porcine eyes, a 7.5-mm trephination was made, followed by capsulorrhexis and lensectomy. The T-TKP was sutured securely onto each eye. Testing the watertight seal at an intraocular pressure of 100 mm Hg was performed before and after pars plana vitrectomy. Results In all 20 eyes, the T-TKP maintained its watertight seal at an intraocular pressure of 100 mm Hg before and after vitrectomy. Conclusion The Landers T-TKP is a reusable device that provides a clear view and watertight eye in the presence of corneal trephinations up to 7.5 mm in diameter. Because of its unique trunkless design, as demonstrated in the laboratory, the T-TKP should allow the surgeon greater flexibility than previous models in cases of ocular trauma.

To determine what organisms enter the eye and remain in the eye after pars plana vitrectomy, vitreous cavity aspirates were cultured postoperatively. Two of 33 (6%) consecutive eyes undergoing primary pars plana vitrectomy had positive cultures. One sample grew a single colony of Staphylococcus epidermidis , the second grew two colonies of Acinetobacter lwoffi. Neither of these eyes developed endophthalmitis. This study demonstrates that bacteria enter the eye at a low rate during pars plana vitrectomy and that the eye on which a vitrectomy has been performed is capable of clearing a low inoculum of bacteria.

Purpose: The purpose of this study is to compare photocoagulation with the argon green, krypton red, and diode infrared laser indirect ophthalmoscopes in an experimental setting. Methods: Photocoagulation was performed with each of the laser indirect ophthalmoscopes in a grid pattern within one sector of the same eye of 14 Dutch-belted rabbits. Treatment was performed either with or without scleral depression. Measurements of the retinal burn diameters were performed after hemisecting the globes, and the burns were examined with light microscopy. Results: Variation in burn intensity and diameter (10% to 28%) was common with all 3 laser indirect ophthalmoscopes. Five times more output energy was required to make equivalent burns with the diode laser indirect ophthalmoscope than with the argon or krypton laser indirect ophthalmoscopes. Choriovitreal hemorrhages only occurred during scleral depression. Histopathologically, the argon green laser indirect ophthalmoscope burns spared the choroid and inner sclera, while the intense krypton and diode burns had full-thickness choroidal involvement and even thermal injury to the inner sclera. Scleral depression reduced the mean energy required to create equivalent burns with all three laser indirect ophthalmoscopes. There was a 10% to 40% reduction in the mean retinal burn diameter with scleral depression (argon green, P P P Conclusion: Photocoagulation with the argon green, krypton red, or diode infrared laser indirect ophthalmoscopes is a safe and effective method of retinal ablation. Decreasing the posterior nodal distance of the eye with scleral depression will produce a smaller spot on the retina with the laser indirect ophthalmoscope.

Subretinal hemorrhages are associated with progressive degeneration of the outer retina and a corresponding poor visual prognosis. Mixed results have been reported in previous attempts to remove such subretinal hemorrhages. We developed an ultramicrosurgical system that used the control of a stereotactic micromanipulator to direct a micropipette tip through a small retinotomy into the subretinal space in three cat eyes. Low-dose recombinant tissue plasminogen activator was then introduced into the subretinal space around the subretinal hemorrhage via a controlled microinfusion system. The recombinant tissue plasminogen activator solution facilitated clot lysis and subsequent removal through the micropipette. Light- and electron-microscopic analysis of histopathologic specimens disclosed good preservation of retinal architecture in the three cat eyes in which experimental subretinal hemorrhages were removed. This was in contrast to the retinal degeneration observed in similar but untreated experimental subretinal hemorrhages.

To explore the feasibility of using human recombinant tissue-type plasminogen activator in the management of subretinal hemorrhage, we examined the toxic effects of a commercial preparation of human recombinant tissue-type plasminogen activator in the subretinal space of the holangiotic retina of the cat. Various concentrations of human recombinant tissue-type plasminogen activator and controls were infused into the subretinal space with a glass micropipette (40- to 60-microns tip) to form a retinal bleb. Concentrations from 2.5 mg/L to 200 mg/L were well tolerated without ultrastructural toxic effects, while 1000 mg/L of human recombinant tissue-type plasminogen activator caused severe, irreversible toxic effects to the photoreceptor-retinal pigment epithelium complex. This toxic effect appeared to be due to the carrier vehicle rather than the human recombinant tissue-type plasminogen activator protein itself. Our results demonstrate that commercially prepared human recombinant tissue-type plasminogen activator can be safely used in the subretinal space of the cat with the range necessary for fibrinolysis.

• Subretinal blood within the macula may cause visual loss in a number of macular diseases. The clinical and histopathologic effects of experimental subretinal hemorrhage were evaluated in the cat. Subretinal hemorrhages were produced by creating a focal neurosensory retinal detachment with micropipette techniques, then inserting a needle tip transsclerally to allow choroidal blood to fill the bleb. Experimental lesions were examined clinically and with light and electron microscopy during a 14-day postoperative period. Initial observations included clot organization with retraction of fibrin strands. In six of nine clots more than 1 hour old, fibrin was associated with tearing of sheets of photoreceptor inner and outer segments. Later degeneration progressed to involve all retinal layers overlying the densest areas of fibrin in the clots. Hemorrhages into subretinal blebs containing tissue plasminogen activator did not form fibrin strands or cause photoreceptor tearing. These findings highlight the potential for improved retinal survival if organized subretinal clot can be eliminated soon after formation.

An inexpensive and reliable fluid-gas exchange system has been developed for vitreous surgery. The system relies on a fish-tank air pump and was compared with the Grieshaber Air System in several laboratory and operating room situations. No significant differences were found between the two systems. Details of the Davis Ocular Air Pump are provided along with a cost analysis.

pupillary margin so that the flow of infusion fluid is downward into the vitreous cavity of the aphakic eye and, hence, away from the corneal endothelium (Fig. 2). The infusion cannula can be sewn onto the sclera in a manner similar to that of a standard pars plana infusion cannula. It is thus possible to approach the vitreous base with a minimal chance of the infusion cannula creating new retinal tears. We have used this infusion cannula successfully on several patients who had severe proliferative vitreoretinopathy and in trauma patients who have dense vitreous hemorrhage and preoperative ultrasonic evidence of a retinal detachment.

Objective To report a series of patients manifesting ulnar neuropathy as an extraocular complication following macular hole surgery and facedown positioning. Methods Retrospective chart review of 7 patients identified by the operating surgeon as developing ulnar neuropathy during the immediate postoperative period after undergoing vitrectomy surgery with fluid-gas exchange for macular hole followed by at least 1 week of strict facedown positioning. Results All 7 patients developed symptoms of ulnar neuropathy, including paresthesias, dysesthesias, pain, weakness, and muscle atrophy. Signs included abnormal electromyogram, prolonged nerve conduction velocities, and impaired neurologic clinical test results in patients examined. Symptoms did not resolve with cessation of facedown positioning, and with follow-up ranging from 3 to 24 months all patients had persistent symptoms. All patients had positioned themselves with their arms continuously flexed. Three of 7 patients had placed pressure directly on their bent elbows. Conclusions Ulnar neuropathy is an extraocular complication of macular hole surgery that can be attributed to arm position during postoperative facedown positioning. Surgeons performing macular hole surgery should caution their patients to minimize the amount of time spent with their elbows in a flexed position. Particular effort should be made to minimize pressure on the bent elbow.

ing illumination. The forceps were partly opened in the eye and the foreign body was tilted slightly, which enabled two of the prongs to extend beneath it while another prong remained anterior to the foreign body. The assistant then retracted the prongs, which allowed the foreign body to be firmly grasped and removed through a limbal incision. Argon green endolaser photocoagulation was applied around the retinal tears. An air-fluid exchange was performed, and CaFg gas was injected into the eye. In the first two postoperative months the retina has remained attached. The patient has subsequently been lost to follow-up.