NODULAR EPIRETINAL MÜLLER CELL GLIOSIS IN THE FOVEA

PURPOSE

The purpose of this study was to report the findings of a hyperreflective nodular epiretinal gliosis observed with optical coherence tomography presumed to be due to subclinical hyaloidal traction causing Mϋller cell cone gliosis.

METHODS

Retrospective, observational case series.

RESULTS

Six eyes of six patients (mean age: 57 years, range 35-81 years) presented with a nodular epiretinal gliosis and had an average follow-up interval of 26 months (range 1-82 months). The mean baseline best-corrected visual acuity was 0.25 ± 0.17 (Snellen equivalent 20/38.3 ± 16.9). Fundus photography demonstrated a yellowish lesion overlying the fovea. Optical coherence tomography imaging revealed a hyperreflective preretinal lesion with a mean vertical length of 267 μ m (range 185-497) and a mean greatest linear diameter of 312 µ m (range 124-640). There was no vitreoretinal abnormality including vitreomacular traction or epiretinal membrane noted in any eye, and two of six eyes displayed a definitive posterior vitreous detachment. These nodules may have occurred before and persisted even after a posterior vitreous detachment or may have been acquired after the posterior vitreous detachment. The nodules typically remained stable with minimal change although in one eye, a posterior vitreous detachment occurred 6 months after initial presentation and lifted the gliosis off of the retinal surface where it remained attached to the posterior hyaloid.

CONCLUSION

Foveal nodular epiretinal gliosis may occur due to subclinical hyaloidal traction on the Müller cell cone even without obvious vitreoretinal interface abnormality on optical coherence tomography.

VITRECTOMY FOR VITREOUS HEMORRHAGE ASSOCIATED WITH RETINAL VEIN OCCLUSION: Visual Outcomes, Prognostic Factors, and Sequelae

PURPOSE

To report the outcomes of pars plana vitrectomy for vitreous hemorrhage (VH) associated with retinal vein occlusion and to identify prognostic indicators.

METHODS

Interventional, retrospective consecutive case series between 2015 and 2021.

RESULTS

The study included 138 eyes of 138 patients (64 female and 74 male); 81 patients had branch retinal vein occlusion and 57 had central retinal vein occlusion. The mean age was 69.8 years. The mean duration between the diagnosis of VH and surgery was 79.6 ± 115.3 (range, 1-572) days. The mean follow-up was 27.2 months. The logarithm of the minimum angle of resolution visual acuity significantly improved from 1.95 ± 0.72 (Snellen equivalent, 20/1782) to 0.99 ± 0.87 (20/195) at 6 months and to 1.06 ± 0.96 (20/230) at the final visit (both P < 0.001). The visual acuity at 6 months improved by three or more lines in 103 eyes (75%). Postoperative complications during follow-up included recurrent VH in 16 eyes (12%) (of which 8 eyes underwent reoperations), rhegmatogenous retinal detachment in six eyes (4%), and new neovascular glaucoma in three eyes (2%). Worse final visual acuity was significantly associated with older age ( P = 0.007), concurrent neovascular glaucoma ( P < 0.001), central retinal vein occlusion ( P < 0.001), worse preoperative visual acuity ( P < 0.001), postoperative new neovascular glaucoma ( P = 0.021), and postoperative retinal detachment ( P < 0.001). The duration of VH was not associated with visual outcomes ( P = 0.684). Preoperative antivascular endothelial growth factor injections and tamponade did not prevent postoperative recurrent VH.

CONCLUSION

Pars plana vitrectomy is effective for VH associated with retinal vein occlusion, regardless of the duration of hemorrhage. However, pre-existing risk factors and postoperative sequelae may limit visual recovery.

Retrospective Study of Ellipsoid Zone Integrity Following Treatment with Intravitreal Ocriplasmin (OZONE Study)

Purpose

To assess generalized (GD) and focal ellipsoid zone disruption (FD) in patients with symptomatic vitreomacular adhesion (sVMA) using spectral domain optical coherence tomography (SD-OCT) following ocriplasmin.

Patients and methods

OZONE was a Phase 4, retrospective study of patients with sVMA treated with a single intravitreal injection of ocriplasmin (0.125 mg). Data from adult patients with at least 6-month follow-up after ocriplasmin were included. SD-OCT was performed at baseline (within 30 days before ocriplasmin), before Day 21 post-injection (early observation, EO), and by last observation (LO) which was maximally 6 months post-injection. The main outcome measure was the development of new and the evolution of existing FD/GD at EO and LO.

Results

The study enrolled 134 eyes/patients from 22 sites in the USA. At baseline, 87 eyes (64.9%) had FD, 21 eyes (15.7%) had GD and 26 eyes (19.4%) had no FD/GD. Among the eyes without FD/GD at baseline, 13 (50%) and 8 (30.8%) developed FD or GD, respectively, by EO. By LO, FD/GD improvement or resolution was seen in >80% of these eyes. Among the eyes with FD/GD at baseline, <40% had improving/resolving EZ integrity at LO. The absence of FD/GD at baseline was associated with less persistent FD/GD at LO (P<0.0005). The presence of FD with MH at baseline was associated with persistent FD at LO (P=0.027).

Conclusion

The fact that a large majority of eyes had FD/GD prior to ocriplasmin was unexpected and demonstrates that EZ disruptions are common in sVMA. This suggests that loss of EZ integrity may be part of the natural history of this disorder. It is hypothesized that the status of the EZ at baseline is a contributing, ocriplasmin independent modulator of subsequent EZ changes after ocriplasmin. Prospective analyses which include a sham control group would be required to test this hypothesis.

Resolution of Pseudophakic Cystoid Macular Edema: 2 mg Intravitreal Triamcinolone Acetonide versus 40 mg Posterior Sub-Tenon Triamcinolone Acetonide

PURPOSE

To compare 2 mg intravitreal triamcinolone (IVT) versus 40 mg posterior sub-Tenon triamcinolone acetonide (STT) for the treatment of eyes with pseudophakic cystoid macular edema.

METHODS

A retrospective, single-center review of eyes receiving 2 mg IVT between 3/1/2012-3/1/2017 and 40 mg STT between 1/1/2015-3/1/2017. Visual acuity (VA) and central macular thickness (CMT) were recorded at baseline, 1-, 3-, and 6-month follow-up visits.

RESULTS

Forty-five eyes were included in the IVT group and 50 eyes in the STT group. Change in VA from baseline to 1, 3, and 6 months was not significantly different between IVT and STT (6 months: 2.3 lines vs. 2.4 lines, p = .10). The IVT group achieved significantly better CMT improvement from baseline compared to STT at 1 month (255 μm vs. 187 μm; p = .03), but this difference was not present at month 3 (214 μm vs. 212 μm; p = .79) or month 6 (176 μm vs. 207 μm; p = .29). During the 6-month follow-up period, approximately 7% of eyes in the IVT group and 12% of eyes in the STT group developed ocular hypertension (p = .43), and all cases were successfully managed with topical anti-ocular hypertensive therapy or observation.

CONCLUSIONS

2 mg IVT and 40 mg STT both achieved significant improvement in vision and CMT with no significant difference between interventions at 3- and 6-month follow-up.

Outcomes of Eyes Lost to Follow-up with Proliferative Diabetic Retinopathy That Received Panretinal Photocoagulation versus Intravitreal Anti-Vascular Endothelial Growth Factor

PURPOSE

To compare anatomic and functional outcomes in eyes with proliferative diabetic retinopathy (PDR) that were lost to follow-up (LTFU) for more than 6 months after treatment with either intravitreal injection (IVI) of anti-vascular endothelial growth factor (VEGF) agents or panretinal photocoagulation (PRP).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Fifty-nine patients who were LTFU immediately after treatment for more than 6 months between September 2013 and September 2016.

METHODS

Patients with eyes receiving either intravitreal anti-VEGF treatment or PRP with the next follow-up visit occurring more than 6 months after treatment were identified. Visual acuity (VA) and anatomic outcomes at the visit before being LTFU, the return visit, the 6-month visit after return, the 12-month visit after return, and the final visit were gathered and compared between the 2 treatment groups.

MAIN OUTCOMES MEASURES

Visual acuity and anatomic outcomes.

RESULTS

Seventy-six eyes of 59 patients were included in the study, of which 30 received IVI with anti-VEGF and 46 received PRP. In the anti-VEGF group, mean VA worsened significantly when comparing the visit before being LTFU (0.43±0.38 logarithm of the minimum angle of resolution [logMAR]) with the return visit (0.97±0.80 logMAR; P = 0.001) as well as with the final visit (0.92±0.94 logMAR; P = 0.01). In the PRP group, mean VA worsened significantly when comparing the visit before being LTFU (0.42±0.34 logMAR) with the return visit (0.62±0.64 logMAR; P = 0.03). However, no significant difference was observed at the final visit (0.46±0.47 logMAR; P = 0.38). There was a significantly greater number of eyes with tractional retinal detachment in the IVI group compared with the PRP group at the final visit (10 vs. 1, respectively; P = 0.005). There was a significantly greater incidence of neovascularization of the iris in the IVI arm compared with the PRP arm at the final visit (4 vs. 0, respectively; P = 0.02).

CONCLUSIONS

Eyes with PDR that received only intravitreal anti-VEGF demonstrated worse anatomic and functional outcomes after being LTFU compared with eyes that received PRP. Given the potential sequelae of being LTFU, the choice of treatment for PDR must be considered carefully.

Topical Dorzolamide-Timolol With Intravitreous Anti-Vascular Endothelial Growth Factor for Neovascular Age-Related Macular Degeneration

IMPORTANCE

There is a subset of eyes with neovascular age-related macular degeneration (AMD) that have persistent exudation despite fixed-interval intravitreous anti-vascular endothelial growth factor (VEGF) injections.

OBJECTIVE

To evaluate the effect of topical dorzolamide hydrochloride-timolol maleate on anatomic and functional outcomes in eyes with neovascular AMD and incomplete response to anti-VEGF therapy.

DESIGN, SETTING, AND PARTICIPANTS

An exploratory, prospective single-arm interventional study at a tertiary referral academic private practice. Patients with neovascular AMD and persistent macular edema despite fixed-interval intravitreous anti-VEGF therapy were enrolled. Baseline spectral-domain optical coherence tomography and clinical data, including visual acuity and intraocular pressure, were obtained at enrollment and from one visit before enrollment. The study was performed at the Retina Service of Wills Eye Hospital and the offices of Mid Atlantic Retina from February 1, 2015, through September 30, 2015. Patients were followed up for at least 2 visits after enrollment. Central subfield thickness, maximum subretinal fluid height, and maximum pigment epithelial detachment height from spectral-domain optical coherence tomography were recorded at each visit.

INTERVENTIONS

Enrolled eyes received a regimen of topical dorzolamide-timolol twice daily and continued to receive the same intravitreous anti-VEGF therapy at the same interval as received before enrollment for the duration of the study.

MAIN OUTCOMES AND MEASURES

Change in central subfield thickness was the primary outcome measure. Changes in maximum subretinal fluid height, maximum pigment epithelial detachment height, and visual acuity were the secondary outcome measures.

RESULTS

Ten patients (10 eyes) completed the study. The mean age of the patients was 78.2 years (age range, 65-91 years), and 6 were male. Eight eyes received intravitreous aflibercept, and 2 eyes received intravitreous ranibizumab. All study eyes had been receiving long-term anti-VEGF therapy with the same medication before study enrollment for a mean of 21.9 injections. The mean central subfield thickness decreased from 419.7 μm at enrollment to 334.1 μm at the final visit (P = .01). The mean maximum subretinal fluid height decreased from 126.6 μm at enrollment to 49.5 μm at the final visit (P = .02). The mean maximum pigment epithelial detachment height decreased from 277.4 μm at enrollment to 239.9 μm at the final visit (P = .12). The mean logMAR visual acuity were 0.54 at enrollment and 0.48 at the final visit (P = .60).

CONCLUSIONS AND RELEVANCE

These data suggest that topical dorzolamide-timolol may reduce central subfield thickness and subretinal fluid in eyes with persistent exudation despite consistent, fixed-interval intravitreous anti-VEGF treatment for neovascular AMD.

Serous macular detachment in Waldenström macroglobulinemia: a report of four cases

PURPOSE

To describe a series of 4 patients with Waldenström macroglobulinemia and serous macular detachment, and propose a mechanism for development of subretinal fluid based on optical coherence tomography (OCT) findings.

DESIGN

Retrospective observational case series.

METHODS

The records of patients with Waldenström macroglobulinemia and OCT documentation of serous macular detachment at Wills Eye Institute were reviewed. Data collection included clinical examination, as well as findings on fluorescein angiography (FA) and OCT.

RESULTS

Four patients (8 eyes) with Waldenström macroglobulinemia and serous retinal detachment were identified. All eyes had varying degrees of venous stasis retinopathy and intraretinal edema overlying the macular detachment. Three patients had no FA leakage, while 1 patient had macular leakage in a petaloid pattern. Focal outer retinal defects within the detached retina were seen in 4 eyes on OCT imaging. In one eye, development of cystoid macular edema was observed before the outer retinal defect and serous macular detachment. All patients with serous macular detachment had some degree of outer retinal disruption.

CONCLUSION

Discontinuity of the outer retina within the macular detachment may enable immunoglobulins along with accumulated intraretinal fluid to flow into the subretinal space, creating a serous retinal detachment. Even with systemic treatment of the underlying Waldenström macroglobulinemia, the visual prognosis was guarded.

GLP-1 based therapies: differential effects on fasting and postprandial glucose

Glucagon-like peptide-1 (GLP-1), a gut-derived hormone secreted in response to nutrients, has several glucose and weight regulating actions including enhancement of glucose-stimulated insulin secretion, suppression of glucagon secretion, slowing of gastric emptying and reduction in food intake. Because of these multiple effects, the GLP-1 receptor system has become an attractive target for type 2 diabetes therapies. However, GLP-1 has significant limitations as a therapeutic due to its rapid degradation (plasma half-life of 1-2 min) by dipeptidyl peptidase-4 (DPP-4). Two main classes of GLP-1-mediated therapies are now in use: DPP-4 inhibitors that reduce the degradation of GLP-1 and DPP-4-resistant GLP-1 receptor (GLP-1R) agonists. The GLP-1R agonists can be further divided into short- and long-acting formulations which have differential effects on their mechanisms of action, ultimately resulting in differential effects on their fasting and postprandial glucose lowering potential. This review summarizes the similarities and differences among DPP-4 inhibitors, short-acting GLP-1R agonists and long-acting GLP-1R agonists. We propose that these different GLP-1-mediated therapies are all necessary tools for the treatment of type 2 diabetes and that the choice of which one to use should depend on the specific needs of the patient. This is analogous to the current use of modern insulins, as short-, intermediate- and long-acting versions are all used to optimize the 24-h plasma glucose profile as needed. Given that GLP-1-mediated therapies have advantages over insulins in terms of hypoglycaemic risk and weight gain, optimized use of these compounds could represent a significant paradigm shift for the treatment of type 2 diabetes.

Ranibizumab for eyes previously treated with pegaptanib or bevacizumab without clinical response

BACKGROUND AND OBJECTIVE

To assess the safety and efficacy of ranibizumab in patients who had inadequate response to pegaptanib or bevacizumab.

PATIENTS AND METHODS

In this single-center study, 19 patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD) previously treated with pegaptanib (n = 1), bevacizumab (n = 13), or both (n = 5) received 12 monthly ranibizumab injections (0.5 mg). Outcomes were measured from start of previous therapy (baseline) to start of ranibizumab treatment (day 0) through 12 months.

RESULTS

No drug- or injection-related adverse events and no serious adverse events were reported. At 6 and 12 months, 4 and 5 patients gained 3 or more lines of VA, respectively; 3 patients lost less than 3 lines of VA at 6 months, and 6 patients lost less than 3 lines at 12 months. At 6 and 12 months, VA increased by a mean (± standard error of the mean) of 2.06 ± 1.23 and 1.17 ± 0.62 lines, respectively. Central retinal thickness decreased by a mean of 62.65 ± 22.46 and 62.16 ± 29.20 μm at months 6 and 12, respectively. When stratified by pigment epithelial detachment (PED) status, patients without PED had better visual and anatomical outcomes than patients with PED.

CONCLUSION

Ranibizumab has favorable safety and efficacy profiles for patients with AMD without previous response to pegaptanib or bevacizumab.

Sterile endophthalmitis following intravitreal injection of preservative-free triamcinolone acetonide

PURPOSE

To describe two cases of sterile endophthalmitis following intravitreal injection of preservative-free triamcinolone acetonide.

METHODS

Chart review.

RESULTS

Two patients with histories of sterile inflammatory reaction to intravitreal Kenalog (triamcinolone acetonide) subsequently were treated with intravitreal injections of preservative-free triamcinolone. Both patients presented 2 to 3 days after injection with significant anterior chamber cell reaction without pain or inflammation-related conjunctival injection. The intraocular inflammation of both patients resolved completely using only topical steroids and antibiotics.

CONCLUSIONS

An inflammatory reaction to the vehicle has been the leading hypothesis for the etiology of the sterile inflammatory response following intravitreal Kenalog injections. The use of preservative-free triamcinolone is intended to eliminate this potential source of toxicity. These cases demonstrate that noninfectious endophthalmitis can develop even with preservative-free triamcinolone.

Pegaptanib for choroidal neovascularization in treatment-naïve exudative age-related macular degeneration

BACKGROUND AND OBJECTIVE

To evaluate the use of intravitreal pegaptanib in the treatment of choroidal neovascularization secondary to age-related macular degeneration (AMD) in treatment-naive patients.

PATIENTS AND METHODS

In a consecu-tive, retrospective case series, treatment-naïve patients with exudative AMD were treated with intravitreal pegaptanib. Intravitreal injections were typically given every 6 weeks at the discretion of the treating physician. Snellen visual acuity (VA), clinical course, and adverse events were monitored. A minimum of three pegaptanib injections were given. Retreatment criteria included persistent submacular fluid, macular edema, new macular hemorrhage, and loss of vision.

RESULTS

The average change in VA for all lesions was a loss of 2.9 lines. Fifteen (14%) patients gained more than 3 lines of VA. The average number of in-jections was 4.8. Ninety-two of 111 lesions were able to be categorized by size. Sixty-six patients had small lesions (< 4 disc areas) with an average change of -2.0 lines, and 26 had large lesions (> or = 4 disc areas) with an average change of -5.4 lines (P < .02). Patients with larger lesions were at greater risk for severe visual loss (P < .01). The average follow-up was approximately 31 weeks (range: 12 to 82 weeks) after the first injection.

CONCLUSIONS

Pegaptanib therapy resulted in a 2.9 average line loss in patients when all lesions were considered. Small lesions responded favorably, with 15% of patients gaining more than 3 lines of VA. Larger lesions had an increased risk of progression and poor visual outcome.

Pharmacometrics and the transition to model-based development

As the transition to model-based drug development continues, pharmacometric analysis will have an increasingly important role across the entire life cycle of drug discovery, development, regulatory approval, and commercialization. For this reason, pharmacometrics can--and should--have an integrating function in the transformation to model-based development. This essay describes an approach for formalizing the pharmacometrics process using the disciplines encompassed by enterprise engineering.

Postoperative complications associated with 25-gauge pars plana vitrectomy

BACKGROUND AND OBJECTIVE

To report postoperative complications in eyes undergoing 25-gauge pars plana vitrectomy (PPV).

PATIENTS AND METHODS

Seventy consecutive eyes that underwent 25-gauge PPV for various indications, including epiretinal membrane, non-clearing vitreous hemorrhage, and idiopathic macular hole, and had a minimum follow-up of 12 weeks were reviewed retrospectively. Main outcome measures included best-corrected Snellen visual acuity, intraocular pressure (IOP), intraoperative complications, and postoperative complications.

RESULTS

The mean visual acuity improved from 20/368 preoperatively to 20/105 postoperatively (P < .00005). Intraoperative complications included retinal tears in 2 eyes (2.9%). Postoperative complications included cataract progression in 17 eyes (42.5%), cystoid macular edema exacerbation in 5 eyes (7.1%), and retinal detachment in 1 eye (1.4%). Postoperative day 1 IOP was statistically lower than preoperative IOP in fluid-filled eyes (P = .031) but not in eyes filled with intravitreal air (P = .30) or gas (P = .52). Sclerotomy sutures were required intraoperatively in 5 eyes (7.1%) and postoperative day 1 hypotony was noted in 4 eyes (5.7%). All of these complications were noted in fluid-filled eyes except for one case of postoperative day 1 hypotony with gas tamponade.

CONCLUSIONS

Intraoperative and postoperative complications were rare in this series of 25-gauge PPV. Postoperative cataract progression and hypotony were the most common complications. Fluid-filled eyes appear to have a higher risk of wound leakage and postoperative hypotony after 25-gauge PPV than eyes with air or gas tamponade.

Optical coherence tomography findings in acute retinal pigment epitheliitis

PURPOSE

To report the optical coherence tomography (OCT) findings in three patients with acute retinal pigment epitheliitis (ARPE).

DESIGN

Retrospective, observational case series.

METHODS

The charts of three patients with ARPE were reviewed. Approval from the Institutional Review Board was obtained. Fundus photographs, fluorescein angiograms, and OCT findings were examined.

RESULTS

Three healthy, young patients presented with acute unilateral blurred vision. Ophthalmoscopy revealed fine pigment stippling surrounded by haloes of hypopigmentation. Fluorescein angiography demonstrated transmission hyperfluorescence. OCT showed abnormal foveal hyperreflectivity involving the outer nuclear layer and photoreceptors in all cases. Disruption of the retinal pigment epithelium (RPE) was seen in two cases. With resolution, the abnormal hyperreflectivity decreased in thickness.

CONCLUSIONS

OCT confirms the involvement of the outer neurosensory retina in acute retinal pigment epitheliitis. RPE involvement may be a secondary post-inflammatory response, because one case did not have significant disruption of the RPE.

Pars plana vitrectomy versus combined pars plana vitrectomy-scleral buckle for primary repair of pseudophakic retinal detachment

PURPOSE

To evaluate pars plana vitrectomy (PPV) versus a combined PPV and scleral buckle (PPV/SB) for repair of noncomplex, pseudophakic retinal detachment.

DESIGN

Retrospective, nonrandomized, comparative interventional study.

PARTICIPANTS

One hundred fifty-two eyes of 152 patients followed up for a mean of 10 months. The case series included 68 consecutive patients who underwent PPV and 84 consecutive patients who underwent a PPV/SB for primary repair of primary pseudophakic retinal detachment at Wills Eye Hospital between 2002 and 2004.

METHODS

All primary PPV cases were performed by 2 surgeons who perform primary vitrectomy without regard to location of detachment, number and location of break(s), refractive error, or macula status. All primary PPV/SB were performed by a group of surgeons who solely perform PPV/SB on pseudophakic retinal detachments. All eyes underwent a standard 3-port 20-gauge PPV under wide-field viewing and scleral depression. Endolaser photocoagulation was applied either around the retinal tears or 360 degrees to the vitreous base region followed by gas tamponade. Patients with proliferative vitreoretinopathy grade C or worse were excluded from the study.

MAIN OUTCOME MEASURES

(1) Single surgery anatomic success rates, (2) preoperative and postoperative visual acuity, and (3) complications.

RESULTS

The single surgery anatomic success rate in the primary PPV group was 63 of 68 eyes (92.6%; 95% confidence interval [CI], 84%-98%) and in the primary PPV/SB group was 79 of 84 eyes (94.0%; 95% CI, 87%-98%). Both groups obtained 100% final reattachment rate. There was no statistically significant difference between the success rates (P = 0.75, Fisher exact test). The PPV group's best-corrected postoperative visual acuity demonstrated a +0.10 logarithm of the minimum angle of resolution improvement over the PPV/SB group (P = 0.07). The PPV group had a smaller incidence of postoperative complications (13/68 patients [19.1%] vs. 27/84 patients [32.1%]; P = 0.10, Fisher exact test).

CONCLUSIONS

Primary PPV and PPV/SB seem to have similar efficacy in the repair of a matched group of patients with primary noncomplex pseudophakic retinal detachment. There was no statistically significant difference in complication rate between the 2 groups.

LASER TREATMENT FOR RETINOPATHY OF PREMATURITY

PURPOSE

To assess the number of laser burns applied to the peripheral retina to treat retinopathy of prematurity (ROP) in a recent population of patients and to compare that number with historical data.

METHODS

The authors performed a retrospective chart review of all patients treated for ROP within a single practice from 2002-2004. There were 183 eyes from 93 patients. Sufficient data for analysis were available on 112 eyes from 57 patients. Data from these patients were compared to those of patients reported upon in 1991.

RESULTS

The average number of laser burns applied to the 112 eyes was 2163. Eyes with zone 1 disease had an average of 3077 spots and those with zone 2 disease had an average of 2072 spots. Greater than three months follow-up was available on 42 eyes from 21 patients. Of those eyes, 90% had complete regression of ROP. In an initial report of laser treatment for ROP by several of the same authors in 1991, the average number of laser burns applied for treatment of ROP was 816. There was a 265% increase in the average number of laser applications from the early study to the present.

CONCLUSION

The data indicate that there has been a trend towards more confluent laser treatment to the avascular zone in ROP.

Incidence of Intraocular Pressure Spike and Other Adverse Events after Vitreoretinal Surgery

PURPOSE

To determine the incidence of significant postoperative intraocular pressure (IOP) elevation and other adverse medical events during the first postoperative day in patients undergoing inpatient vitreoretinal surgery.

DESIGN

Noncomparative interventional case series.

PARTICIPANTS

Two hundred two consecutive patients were admitted prospectively as inpatients after vitreoretinal surgery (vitrectomy and/or scleral buckling).

METHODS

Intraocular pressure was measured preoperatively, 5 to 12 hours postoperatively, and on postoperative day 1. Additionally, pain, nausea, and serious systemic adverse events were monitored.

RESULTS

Seventeen patients (8.4%) had a 5- to 12-hour IOP measurement above 29 mmHg. Thirty patients (14.8%) had a postoperative day 1 IOP measurement above 29 mmHg. Three patients (1.5%) required a parenteral narcotic to achieve adequate analgesia. Nine patients (4.5%) utilized a parenteral antiemetic for nausea control. Six patients (3.0%) had a hyperglycemic event. No serious systemic adverse events occurred in the early postoperative period.

CONCLUSIONS

The incidence of a significant IOP spike or systemic adverse events in the early postoperative period in patients undergoing vitreoretinal surgery is low.

Day-long subcutaneous infusion of exenatide lowers glycemia in patients with type 2 diabetes

Exenatide (exendin-4) is an incretin mimetic with potential antidiabetic activity. This study examined the effects of a continuous subcutaneous (SC) infusion of exenatide (0.2, 0.4, 0.6, or 0.8 microg/kg/day) or placebo (PBO) on glycemic control over 23 h intervals. Twelve subjects with type 2 diabetes treated with metformin and/or diet received 10 infusions (4 exenatide, 6 PBO) on consecutive days. Exenatide was given in a dose-increasing design with at least one placebo infusion between each exenatide infusion, and with meals and a snack provided during the first 14 h of infusion. Plasma exenatide concentrations were dose-proportional. Plasma glucose (4-23 h) was lower in all exenatide arms compared to placebo (p<0.0001). The change in insulin/glucagon ratio and amylin concentrations from pre-infusion to post-infusion was increased (p<0.005, p<0.05, respectively) in the combined exenatide arms, but remained unchanged in the placebo groups. Nausea and vomiting were the most common treatment emergent adverse events. Exenatide infusion also appeared to have positive effects on beta-cell and alpha-cell function as measured by proinsulin/insulin ratios and mean glucagon concentrations. In summary, exenatide lowered plasma glucose during both prandial and fasting states when delivered as a continuous SC infusion over twenty-three hours, suggesting that exenatide can provide day-long glycemic control in patients with type 2 diabetes.

Adjunctive Therapy with Pramlintide Lowers HbA1c without Concomitant Weight Gain and Increased Risk of Severe Hypoglycemia in Patients with Type 1 Diabetes Approaching Glycemic Targets

AIMS

In long-term clinical trials in patients with type 1 diabetes spanning a wide range of HbA1c, addition of pramlintide to existing insulin regimens led to reductions in HbA1c that were accompanied by weight loss and no increase in overall severe hypoglycemia event rates. Given that weight gain and increased hypoglycemia risk contribute to the difficulty of attaining HbA1c targets (<7 %), the question arose whether pramlintide could benefit patients approaching, but not reaching glycemic targets with insulin alone. To address this question, we conducted a pooled analysis from 3 long-term clinical trials, including all patients with an entry HbA1c between 7.0 % and 8.5 %.

METHODS

Within the subset of patients with an entry HbA1c between 7.0 % and 8.5 % (approximately 28 % of all patients enrolled in the 3 studies), 196 were treated with placebo + insulin (baseline HbA1c 7.9+/-0.4 %, body weight 76.0+/-14.3 kg [mean+/-SD]) and 281 with pramlintide+insulin (baseline HbA1c 7.9+/-0.4 %, body weight 75.4+/-13.1 kg). Endpoints included placebo-corrected changes from baseline to week 26 in HbA1c, body weight, and the event rate of severe hypoglycemia.

RESULTS

Adjunctive therapy with pramlintide resulted in significant reductions in HbA1c and body weight from baseline to week 26 (0.3 % and 1.8 kg, placebo-corrected treatment differences, respectively, both p<or=0.0009). These changes occurred without an increase in the overall risk of severe hypoglycemia (1.40 pramlintide vs. 1.86 placebo, events/patient-year of exposure).

CONCLUSIONS

Addition of pramlintide to insulin therapy may help patients with type 1 diabetes who are approaching, but not yet reaching, glycemic targets with insulin alone to achieve further reductions in HbA1c without concomitant weight gain and increased risk of severe hypoglycemia.

The human amylin analog, pramlintide, corrects postprandial hyperglucagonemia in patients with type 1 diabetes

Mealtime amylin replacement with the human amylin analog pramlintide as an adjunct to insulin therapy improves postprandial glycemia and long-term glycemic control in type 1 diabetes. Preclinical animal studies indicate that these complementary effects may result from at least 2 independent mechanisms: a slowing of nutrient delivery to the small intestine and a suppression of nutrient-stimulated glucagon secretion. The former effect of pramlintide has previously been demonstrated in patients with type 1 diabetes. The present studies characterize the effect of pramlintide on postprandial glucagon secretion in this patient population. Plasma glucagon and glucose concentrations were measured before and after a standardized liquid meal in 2 separate randomized, double-blind, placebo-controlled studies of pramlintide administration to patients with type 1 diabetes. In a 2-day crossover study, 18 patients received a 5-hour intravenous infusion of pramlintide (25 microg/h or 50 microg/h) or placebo in addition to subcutaneous (SC) insulin injections. In a 14-day parallel-group study, 84 patients received SC injections of 30, 100, or 300 microg of pramlintide or placebo 3 times daily in addition to SC injections of insulin. In both studies plasma glucagon concentrations increased in response to the meal in the placebo-plus-insulin group but not in any of the pramlintide-treated groups (all pramlintide treatment arms v placebo, P <.05). We conclude that mealtime amylin replacement with pramlintide prevents the abnormal meal-related rise in glucagonemia in insulin-treated patients with type 1 diabetes, an effect that likely contributes to its ability to improve postprandial glucose homeostasis and long-term glycemic control.

Glucoregulatory endocrine responses to intermittent exercise of different intensities: plasma changes in a pancreatic beta-cell peptide, amylin

Amylin, a peptide hormone released from the beta cells of the pancreas and cosecreted with insulin, is reported to inhibit the release of postprandial glucagon and insulin and to modulate gastric emptying. Changes in insulin and glucagon are important for controlling blood glucose levels under conditions in which metabolic rate is elevated, such as during and following exercise. Amylin may participate in the regulation of blood glucose levels in response to exercise, although the role of amylin has not been investigated. The purpose of the study was to determine the effects of a progressive, intermittent exercise protocol on amylin concentrations and to compare its response to circulating levels of insulin, glucagon, cortisol, and glucose. Seven well-trained males completed an intermittent exercise trial on a treadmill at four progressive exercise intensities: 60%, 75%, 90%, and 100% of maximum oxygen consumption (.VO(2)max). Blood samples were collected before exercise, after each exercise intensity, and for 1 hour following the exercise protocol. Subjects also completed a control trial with no exercise. Amylin and insulin rose from baseline (5.79 +/-.78 pmol/L and 4.76 +/-.88 microIU/mL) to peak after 100% .VO(2)max (9.16 +/- 1.35 pmol/L and 14.37 +/- microIU/ml), respectively and remained elevated during much of recovery. Thus, a progressive intermittent exercise protocol of moderate to maximum exercise intensities stimulates increases in amylin levels in well-trained individuals in a similar fashion to that of insulin, whereas glucagon concentrations only increase after the greatest exercise intensity, then quickly decline. Future studies should examine the effects of higher amylin concentrations in exercise recovery on glucoregulation.

Ocular paintball injuries

Paintball sport-related ocular injuries represent an increasing problem as the popularity of the sport increases and the number of participants grows. Although eye protective devices designed specifically for paintball sports are extremely effective in preventing such injuries, the failure to properly wear these devices has resulted in an alarming number of severe ocular injuries. Recent trends have indicated that an increasing percentage of paintball sport-related ocular injuries have occurred in unsupervised, noncommercial settings (i.e., backyard games) where the use of eye protective devices is not required. Paintball industry standards for eye protection have recently been developed and should be implemented for all participants.

Safety of indocyanine green angiography during pregnancy: a survey of the retina, macula, and vitreous societies

OBJECTIVES

To establish current practice patterns and assess the general knowledge among vitreoretinal-trained physicians regarding the use of indocyanine green (ICG) angiography during pregnancy, and to review the literature regarding the established safety of ICG angiography in pregnant women.

METHODS

A survey was mailed to 1101 members of the Retina, Macula, and Vitreous Societies.

RESULTS

Of the 520 respondents, 434 (83%) had seen at least 1 pregnant woman who required ICG angiography or fluorescein angiography. Of these, 385 (89%) withheld fluorescein angiography and 105 (24%) withheld ICG angiography, largely because of fear of teratogenicity or lawsuit. Diabetic retinopathy and choroidal neovascular membrane were the most common indications for fluorescein angiography, and choroidal neovascular membrane and choroidal tumor were the most common indications for ICG angiography. Only 24% thought that it was safe to use ICG angiography in a pregnant patient, and only 5% thought it was safer than fluorescein angiography.

CONCLUSIONS

Despite the documented safety of ICG when used for retinal angiography and the extensive experience with the use of intravenous ICG to measure hepatic blood flow in pregnant women, the results of this survey suggest widespread hesitation to use ICG for retinal angiography in pregnant women. Current practice patterns regarding the use of ICG angiography in pregnant patients may be unnecessarily restrictive.

Circulating levels of incretin hormones and amylin in the fasting state and after oral glucose in GH-deficient patients before and after GH replacement: a placebo-controlled study

OBJECTIVE

Hyperinsulinemia in association with GH excess is considered a compensatory response to insulin resistance, but the possibility of alternative insulinotropic mechanisms has not been investigated in vivo. It is also unknown how GH influences the secretion from pancreatic beta-cells of amylin, a peptide which regulates prandial glucose homeostasis and may be linked to development of beta-cell dysfunction. We therefore measured plasma concentrations of two gut insulinotropic hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulin-releasing peptide (GIP), and total as well as non-glycosylated amylin, in 24 GH-deficient adults before and after 4 months of GH replacement (daily evening injections of 2 IU GH/m).

DESIGN

Double-blind, placebo-controlled, parallel study.

METHODS

All participants underwent an oral glucose tolerance test (OGTT) at 0 and 4 months.

RESULTS

A 33% suppression of fasting GLP-1 concentrations was measured in the GH group at 4 months (P=0.02), whereas a non-significant increase occurred in the placebo group (P=0.08). Fasting levels of GIP and amylin did not change significantly after 4 months in either group. The incremental response in GLP-1 during the OGTT was significantly lower after GH treatment as compared with both baseline (P=0.02) and the response in the placebo group (P=0. 03). The stimulation of GIP secretion following OGTT was similar on all occasions. The OGTT-induced incremental response in non-glycosylated amylin was moderately elevated after GH treatment as compared with placebo (P=0.05). Plasma concentrations of glucose and insulin, both in the fasting state and after the OGTT, were higher after GH treatment, but the ratio between amylin and insulin remained unchanged.

CONCLUSIONS

GH-induced hyperinsulinemia is accompanied by proportionate elevations in amylin concentrations and a blunting of gut GLP-1 secretion. The mechanisms underlying the suppression of GLP-1 remain to be elucidated.

Deficiency of total and nonglycosylated amylin in plasma characterizes subjects with impaired glucose tolerance and type 2 diabetes

This study was undertaken to characterize first and second phase secretory profiles of total and nonglycosylated amylin and insulin and to determine whether excessive glycosylation of amylin or hyperamylinemia is a feature of abnormal glucose tolerance in humans. Plasma concentrations of total and nonglycosylated amylin and serum immunoreactive insulin were measured under identical hyperglycemic conditions using the hyperglycemic clamp technique in subjects with type 2 diabetes, impaired and normal glucose tolerance. Both amylin and insulin concentrations followed a biphasic pattern in subjects with normal and impaired glucose tolerance. In the subjects with normal and impaired glucose tolerance, the second phase amylin concentrations markedly exceeded those of the first phase, whereas the reverse was true for insulin. The first phase concentrations of both peptides were significantly lower in impaired than the normal glucose tolerance subjects. In patients with type 2 diabetes no first phase peak for either amylin or insulin could be identified, and the second phases of both amylin and insulin were significantly lower compared to subjects with normal or impaired glucose tolerance. Nonglycosylated amylin concentrations accounted for 25-45% of total amylin, regardless of glucose tolerance, and mimicked the pattern of total amylin concentrations. In summary: 1) glucose-induced increases in the magnitude of the first and second phase amylin plasma concentrations differed from those of insulin; 2) subjects with impaired glucose tolerance and more strikingly those with type 2 diabetes have impaired amylin responses; and 3) the ratio of nonglycosylated to total amylin is normal irrespective of glucose tolerance. These data imply, in view of many reports describing accumulation of amyloid in the pancreas, that circulating levels of amylin decrease as amyloid deposits accumulate and beta-cell function deteriorates and that the amount of glycosylated amylin in plasma is not increased in patients with type 2 diabetes.

Changing trends in paintball sport-related ocular injuries

OBJECTIVES

To describe the type and severity of ocular injuries caused by paintballs, to summarize the outcomes, to determine if the injury occurred in a commercial or noncommercial setting, to compare the number of injuries in each setting as a function of time, and to ascertain whether eye-protective devices were worn and why they were removed.

DESIGN

Retrospective analysis of 35 patients who sustained ocular injuries caused by paintballs and underwent evaluation and treatment at an eye hospital from January 1, 1985, to September 30, 1998. Thirty-five eyes of 35 patients underwent a complete ocular examination, diagnostic testing, and surgical intervention when indicated.

RESULTS

All patients were male (average age, 22 years). Twenty-six patients (74%) had an initial visual acuity of 20/200 or worse, and visual acuity in 16 (46%) remained 20/200 or worse on follow-up (range, 2 weeks to 22 months). Traumatic hyphema was seen in 21 patients (60%). Twenty-two patients (63%) had access to goggles, 7 (33%) of whom removed them due to fogging before the injury. Injuries sustained after 1995 were 5.8 times (relative risk, 5.8; 95% confidence interval, 1.5-22.4) more likely to occur during a noncommercial war game than those occurring in 1995 or before.

CONCLUSIONS

As the popularity of war games increases, so does the potential for serious ocular injury caused by paint pellet guns. Most injuries seen after 1995 occurred in noncommercial war game settings, where the use of eye-protective devices is not required. Industry standards for eye protection have been developed recently and should be implemented.

Arteriovenous adventitial sheathotomy for the treatment of macular edema associated with branch retinal vein occlusion

PURPOSE

To report arteriovenous adventitial sheathotomy for treatment of macular edema associated with branch retinal vein occlusion.

METHODS

Case reports with review. Five eyes of five patients with best-corrected visual acuity of less than 20/200 secondary to branch retinal vein occlusion had pars plana vitrectomy and arteriovenous adventitial sheathotomy and were followed postoperatively for a mean of 6.5 years (range, 5 to 7 years).

RESULTS

In four of five eyes, the best-corrected visual acuity improved to 20/30 to 20/70. In the remaining eye, visual acuity remained at finger counting secondary to macular ischemia.

CONCLUSION

Arteriovenous adventitial sheathotomy may be beneficial for select patients with poor vision secondary to branch retinal vein occlusion.

A new approach to an old problem

A patient with progressive visual loss was found to have an optic nerve sheath meningioma. The patient was treated with stereotactic radiotherapy, a computer-guided stereotactic technique that minimizes the risk of radiation-induced optic neuropathy. Six months after treatment, the patient was doing well and showed no signs of radiation-induced optic neuropathy.

Ultrasound biomicroscopy as a tool for detecting and localizing occult foreign bodies after ocular trauma

OBJECTIVE

To show the utility of ultrasound biomicroscopy (UBM) in imaging small ocular foreign bodies of the anterior segment.

DESIGN

Retrospective case series.

PARTICIPANTS

Twelve eyes of 12 consecutive patients evaluated in the emergency department or referred to specialty services at 1 institution between August 1994 and November 1997 were examined.

INTERVENTION

Ocular ultrasound biomicroscopy was performed.

MAIN OUTCOME MEASURES

Detection and localization of an ocular foreign body were measured.

RESULTS

An intraocular or superficial foreign body was detected by UBM in 9 (75%) of 12 eyes. The foreign body was classified as corneal in two eyes, subconjunctival in two, intrascleral in three, and intraocular in two eyes. The foreign body was not visible by ophthalmic physical examination in seven of the nine eyes with a confirmed ocular foreign body. In the remaining two eyes, UBM was used to determine the depth of a visible foreign body. In three of the eyes with a confirmed foreign body, computed tomography and/or contact B-scan ultrasonography was obtained and failed to show a foreign body. Six of the foreign bodies were nonmetallic.

CONCLUSIONS

Clinical detection of ocular foreign bodies after trauma can be hindered by small size, haziness of the optical media, poor patient cooperation, or hidden location. Ultrasound biomicroscopy is a valuable adjunct in the evaluation of suspected ocular foreign bodies, especially in cases involving small, nonmetallic objects.

Impaired phasic insulin and amylin secretion in diabetic rats

We have proposed that a hyperstimulated insulin secretion causing beta-cell degranulation is the basis for the impaired glucose-potentiated insulin secretion in type 2 diabetes ("overworked beta-cell"). To confirm this idea, we previously investigated tolbutamide-infused euglycemic rats. Two novel kinds of beta-cell dysfunction were observed: altered phasic glucose-potentiated insulin secretion with preferential sparing of the first phase and a raised secreted ratio of amylin to insulin. The current study tested these parameters in 90% (intact beta-cell insulin stores) and 95% (markedly lowered insulin stores) pancreatectomized (Px) diabetic rats. Rats underwent pancreas perfusion 5-6 wk postsurgery. Controls showed nonchanging insulin secretion during a 20-min perfusion of 16.7 mM glucose + 10 mM arginine. In contrast, both Px groups showed an altered phasic pattern, with the first phase being supernormal (for the beta-cell mass) but the second phase reduced in tandem with the insulin content. Amylin secretion from control and 90% Px rats paralleled the insulin output, so that the amylin-to-insulin ratio averaged 0. 12 +/- 0.03% in the controls and 0.16 +/- 0.01% in the 90% Px rats over the two secretory phases. In contrast, the amylin-to-insulin ratio in 95% Px rats equaled that of controls during the first phase (0.12 +/- 0.1%) but was twice normal during the second phase (0.32 +/- 0.4%). These results confirm the validity of the overworked beta-cell schema by showing identical beta-cell functional defects in Px rats and tolbutamide-infused normoglycemic rats.

Plasma amylin immunoreactivity and insulin resistance in insulin resistant relatives of patients with non-insulin-dependent diabetes mellitus

To explore the potential relationship between concentrations of circulating amylin and the insulin resistance observed in first-degree relatives of patients with non-insulin-dependent-diabetes mellitus (NIDDM), we studied 40 relatives compared to 35 matched controls. Two newly developed immunoassays that measure either non-glycosylated or total amylin were applied. All subjects were examined by an oral glucose tolerance test (OGTT) and by a hyperinsulinemic euglycemic clamp (insulin infusion: 0.6 mU/kg/min). Glucose tolerance was normal in all, but insulin-stimulated glucose uptake (Rd) was diminished in the relatives (p < 0.001). Area under the curves (AUCs) during OGTT for plasma glucose (p < 0.01) and serum insulin (p=0.08), but not for plasma total and non-glycosylated amylin, were higher in relatives versus controls. In both groups, inverse correlations were found between Rd and AUC for plasma total and non-glycosylated amylin (p [all]<0.05). However, in multiple linear regression analyses, plasma total and non-glycosylated amylin failed to influence Rd independent of serum insulin and family history-of NIDDM. In conclusion, this study demonstrated inverse correlations between Rd and circulating concentrations of plasma total and non-glycosylated amylin in relatives and matched controls. These data, however, do not support the hypothesis that physiological amylin concentration are a major importance for the insulin resistance in relatives of NIDDM patients.

Melanocytomalytic glaucoma in eyes with necrotic iris melanocytoma

OBJECTIVE

Iris melanocytoma, although histologically benign, may undergo spontaneous necrosis with the resultant pigment dispersion causing secondary open-angle glaucoma. The authors describe the clinical findings in three patients with this syndrome and review the current literature.

DESIGN

The study design was a small case series.

PARTICIPANTS

Three patients with secondary glaucoma caused by a necrotic iris melanocytoma participated.

INTERVENTION

Clinical records and pathologic preparations were reviewed. The diagnosis of iris melanocytoma was confirmed by histopathologic examination in all three cases.

RESULTS

All patients had intrinsically pigmented localized iris tumors and pigmentation of the angle. Hyperchromic heterochromia iridum was noticeable in all patients. In two instances, a central crater in the lesion signified tumor necrosis. Two patients were treated successfully by surgical resection of the iris tumor and the glaucoma resolved. One patient was treated with enucleation. In all patients, histopathologic analysis disclosed extensively necrotic tumor comprised of maximally pigmented nevus cells with bland nuclei and infiltration of the trabecular meshwork by melanophages.

CONCLUSION

Secondary glaucoma may result from obstruction of the trabecular meshwork with necrotic iris melanocytoma. Resection of the tumor may relieve the glaucoma.

The role of ultrasound biomicroscopy in ocular trauma

PURPOSE

To demonstrate the usefulness of ultrasound biomicroscopy (UBM) in detecting and localizing small ocular foreign bodies.

METHODS

This is a retrospective study of the records of 555 consecutive patients evaluated by UBM by the Visual Physiology Unit of the Wills Eye Hospital from August 1994 to November 1997.

RESULTS

In 9 patients, a foreign body was identified. In 6 patients, the history suggested the presence of a foreign body, but one could not be detected by clinical examination. In 2 patients, the referring physicians requested UBM to determine whether or how deep a known foreign body had penetrated the globe. In 1 patient, the foreign body was not suspected clinically. In regard to other diagnostic techniques, CT failed to identify the foreign body in 1 patient. In another, contact B-scan ultrasonography failed. In a third, both CT and contact B-scan ultrasonography failed. The foreign body was intracorneal in 2 eyes, subconjunctival in 2, intrascleral in 3, and intraocular in 2. Six were nonmetallic. Two were metallic. In one case, the foreign body was lost and its composition is unknown. In 5 cases, the UBM findings altered the patient's management.

CONCLUSIONS

UBM is a valuable adjunct in the evaluation of small, anteriorly located foreign body that may not be detectable by other methods. UBM may be especially useful for finding nonmetallic foreign bodies.