COMBINED PNEUMATIC AND ENZYMATIC VITREOLYSIS FOR SEVERE CASES OF VITREOMACULAR TRACTION

PURPOSE

To evaluate the efficacy of combined pneumatic and enzymatic vitreolysis for treatment of severe cases of vitreomacular traction (VMT).

METHODS

We analyzed a retrospective, consecutive series of five patients diagnosed with severe VMT refractory to pneumatic vitreolysis who then received an additional ocriplasmin injection while their gas bubble from pneumatic vitreolysis was still present between February 2015 and February 2019. Vitreomacular traction release was confirmed using spectral-domain optical coherence tomography.

RESULTS

Four of the five patients treated with combined pneumatic and enzymatic vitreolysis achieved VMT release by Day 28, and all cases eventually achieved complete VMT release. In addition to having VMT refractory to pneumatic vitreolysis, patient characteristics included broad adhesion diameter (>1,500 µ m, n = 1), presence of epiretinal membrane (n = 2), age >65 years (n = 4), and pseudophakia (n = 1). The visual acuity improved by three or more lines at 6 months in both of the patients with initial vision worse than 20/50 on an Early Treatment Diabetic Retinopathy Study chart but not in those whose vision was already fairly good (i.e., visual acuity >20/60). None of the patients experienced the following complications after receiving this combined treatment: retinal tears or detachments, vitreous floaters, and ellipsoid zone changes.

CONCLUSION

Sequential, combined pneumatic and enzymatic vitreolysis resulted in VMT release in all 5 cases (4 cases by 28 days) and may be a potentially useful alternative to surgical intervention for refractory VMT cases.

Endoscope-Assisted Sutureless Intrascleral Haptic Fixation of a Posterior Chamber Intraocular Lens

Purpose:

In eyes with compromised capsule support, sutureless scleral fixation is a popular method of placing a posterior chamber intraocular lens (PCIOL). We describe an endoscope-assisted sutureless technique for intrascleral fixation of a 3-piece PCIOL.

Methods:

Eyes of patients who had endoscope-assisted scleral-fixated intraocular lens (SFIOL) implantation were examined retrospectively. The technique comprised direct capture of the IOL haptic with a forceps through a pars plana sclerotomy with subsequent haptic fixation into scleral tunnels created with a 26-gauge needle. The endoscope was used to visualize haptic positioning under the iris and ensure proper centration of the IOL.

Results:

Thirteen eyes of 13 patients were examined. The mean age of the patients was 68.2 years (range, 38-87 years), and the mean follow-up was 13.6 months (range, 5-23 months). The indications for surgery were a subluxated IOL (6 eyes), postoperative aphakia (5 eyes), and a subluxated cataract (2 eyes). The mean best-corrected visual acuity ± SD improved significantly from 1.2 ± 0.6 logMAR preoperatively to 0.6 ± 0.7 logMAR at last the follow-up (paired Welch t test; t10 = 2.69; P = .023). IOL stability and centration were maintained in all patients.

Conclusions:

Endoscopic visualization during sutureless SFIOL implantation helped improve haptic localization, minimize intraoperative complications, and achieve excellent IOL centration.

Nocturnal normobaric hyperoxia treatment in a case of chronic diabetic macular edema

PURPOSE

To study the long-term anatomic and physiologic effects of nocturnal normobaric hyperoxia (NNBH) in a patient with treatment-resistant diabetic macular edema (DME).

METHODS

A 64-year-old diabetic man with bilateral DME requiring regular anti-VEGF treatments in both eyes was started on 5 LPM (40% FiO2) NNBH treatment 6-h per night. Visual acuity, OCT measurements of retinal thickness and volume, as well as the number of injections given in each eye were retrospectively examined one year prior and prospectively after initiation of NNBH, as well as before and after a planned 1-month discontinuation of NNBH.

RESULTS

The patient received 12 anti-VEGF injections in the year prior to beginning NNBH treatment (4 OD; 8 OS) and did not require any injections after commencing NNBH treatment. Visual acuity improved and stabilized to 20/20 and macular edema rapidly resolved in both eyes following initiation of NNBH. After a planned 1-month NNBH vacation, DME recurred but quickly resolved once NNBH treatment was restarted.

CONCLUSION

This model case demonstrates that a 6-h NNBH regimen can be successful in treating DME and improving vision, without the need for intravitreal injections. NNBH is a more acceptable treatment regimen compared to 24-h continuous oxygen delivery and may provide a less invasive alternate method for treating DME in patients with diabetes. Further study is warranted.

Intravitreal Methotrexate for Recalcitrant Epiretinal Membrane Reproliferation

This article reports a case of a 65-year-old woman with recalcitrant recurrent epiretinal membrane (ERM) treated with revision vitrectomy and membrane peeling followed by 12 weekly intravitreal methotrexate injections. Visual acuity and central macular thickness significantly improved, and no ERM recurrence developed 7 months after surgery. This case represents the first documented use of methotrexate to treat surgically resistant ERM reproliferation and indicates a potential for its use in cases that do not respond to standard treatment. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:49-51.].

Anterior versus posterior endoscopic cyclophotocoagulation: comparison of indications, populations, and outcomes

PURPOSE

To examine how indications, patient characteristics, and outcomes differ between anterior and posterior approaches of endoscopic cyclophotocoagulation (ECP) in the treatment of glaucoma.

METHODS

This is a retrospective chart review of 9 anterior and 20 posterior ECP cases (n = 29).

RESULTS

Posterior ECP cases were typically associated with a dramatic increase in intraocular pressure (IOP), whereas the anterior ECP was associated with chronically elevated pressures. The initial IOPs in mm Hg of posterior ECP cases (26.8 non-NVG; 35.2 NVG) were much greater than anterior ECP cases (17.8), and a greater overall reduction in IOP was observed in the posterior versus anterior ECP cases (10.3 posterior non-NVG; 21.3 posterior NVG; 3.6 anterior, P < .001). With procedural success defined as 6-month post-operative IOP falling within normal ranges and a decrease in either IOP or number of prescribed glaucoma medications, the success rate of ECP was 92% for posterior NVG, 89% for anterior and 75% for posterior non-NVG cases (P = .34), similar to the previous literature. Of the four unsuccessful cases, two resulted in a normal IOP but lacked a drop in pressure or reduction in medication burden, one resulted in a 6-point drop in IOP but remained at 23 mm Hg, and one resulted in phthisis bulbi (3%) from an initial pressure above 40 mm Hg.

CONCLUSION

Endoscopic cyclophotocoagulation is an effective and safe procedure for severe glaucoma cases from both an anterior and posterior approach. Ophthalmologists should consider this procedure as part of their glaucoma treatment arsenal.

Relative Retinal Blood Flow: A Novel and Informative Measure of Unilateral Retinal Vein Occlusion Severity

Purpose

This study quantifies retinal vascular blood flow affected by unilateral central or branch retinal vein occlusion (CRVO or BRVO). We created a new, unitless metric for the severity of these diseases—relative blood flow (RBF)—and contextualized it with subject demographics, ocular presentation, and systemic conditions. Finally, we explored its efficacy as a predictor of future outcomes.

Methods

Data were collected from 20 control subjects and 32 clinically diagnosed CRVO (n = 15) or BRVO (n = 17) patients. We used laser speckle flowgraphy to quantify blood flow as mean blur rate and present RBF as the ratio between the blood flow in a subject's diseased and undiseased eyes. Because of our demonstration that blood flow has high intrapatient (between eyes and over time) but low interpatient correlation in eyes of healthy subjects, any differences between eyes can be attributed to the disease. These data were correlated with subject demographics and disease characteristics.

Results

In CRVO and BRVO eyes, average blood flow decreased by 26% and 7%, respectively. In CRVO, occlusion duration, central macular thickness, intraocular pressure, diabetes, previous laser and injection treatments, and injection within three months after measurement were significantly associated with RBF. In BRVO, no significant associations with RBF were found.

Conclusions

Blood flow in CRVO and BRVO was reduced compared to the unaffected fellow eye in most patients. RBF was useful in determining the severity of RVOs and predicting future treatment needs.

Translational Relevance

RBF is a promising new and informative metric for quantifying the severity of unilateral RVOs.

Rapid reduction of macular edema due to retinal vein occlusion with low-dose normobaric hyperoxia

PURPOSE

We investigated the effects of a relatively inexpensive, non-invasive, short-term treatment with low-dose normobaric hyperoxia (NBH) on macular edema in patients with retinal vein occlusion (RVO).

METHODS

Participants with macular edema associated with RVO were treated with 5 LPM of NBH via facemask (40% fraction of inspired oxygen, FIO2) for 3 h. Patients with non-fovea involving edema who elected to be observed returned for a second treatment 1 month later to test reproducibility.

RESULTS

A 3-h session of NBH (n = 45) resulted in decreased maximum macular thickness (MMT) (mean 7.10%, t₃₄=9.63 P<.001) and central macular thickness (CMT) (mean 4.64%, t₃₄=6.90, P<.001) when compared to untreated eyes with RVO measured over the same period of time (n = 12) or their healthy fellow eye (n = 34; MMT:t₃₄=-9.60, P<.001;CMT: t₃₄=-6.72, P<.001). Patients who had a second NBH treatment 1 month later experienced a recurrence of their edema, but demonstrated a similar significant reduction in MMT and CMT after the second NBH treatment.

CONCLUSIONS

Three-hour treatment with 40% FIO2 NBH results in a significant reduction in MMT and CMT. This study supports an ischemic mechanism for macular edema associated with retinal vein occlusion.

TRANSLATIONAL RELEVANCE

Short-term low-dose normobaric hyperoxia is a simple, inexpensive, and ubiquitous treatment that may provide an alternate or adjunctive approach to treating macular edema in patients who are resistant to or cannot afford anti-VEGF medications.

Recalcitrant Macular Hole Closure by Autologous Retinal Transplant Using the Peripheral Retina

Purpose

The peripheral adult human retina has been found to contain neuroepithelial stem cells. In this study, we examined the efficacy of an auto-transplant of peripheral retina into refractory macular holes (MH) from both anatomic and physiologic perspectives.

Methods

The population consisted of four female patients aged 72, 82, 65 and 84 years (cases 1–4, respectively) with persistent refractory MH status; internal limiting membrane (ILM) peeling (case 1), ILM transplant (case 2), and inverted ILM (cases 3 and 4 with myopic MH). In all our cases, retinal grafts were harvested beyond the equator from the far retinal periphery using curved horizontal scissors and gently moved toward the MH using a forceps. A 25-G manipulator with a silicone ball tip was used to tuck the trimmed graft into the MH, followed by fluid-air exchange and infusion of silicone oil, which was removed three months later.

Results

Partial restoration and integration of the outer retinal layer were confirmed on an OCT-B scan imaging. The visual acuity (VA) was improved in all cases: 1.2 to 1.0 logMAR (case 1), 2.0 to 1.3 logMAR (case 2), 2.3 to 1.4 logMAR (case 3) and 2.0 to 1.0 logMAR (case 4). Microperimetry showed improved retinal sensitivity in every case. No intra- or post-operative complications were observed.

Conclusion

Under pathological conditions, the Müller glia reportedly serves as a source of neuronal progenitor cells in regenerating retina, continuing to divide and migrate to the outer nuclear layer thus replacing lost photo-receptors. Although the histological findings remain unknown, the positive anatomic and physiologic outcomes of the auto-transplanted retinal flap in our series suggest that this technique may offer an effective option for treating recalcitrant MH. Further studies are warranted.

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In Vivo Photoactivation of Caged-Thrombin

Aberrant ocular neovascularization is a major cause of blindness in the world. Abnormal blood vessels in the eye may produce corneal opacification, corneal transplant rejection, neovascular glaucoma, vitreous hemorrhage, traction retinal detachment, and subretinal scars from choroidal neovascular membranes (1-5). Light-induced clotting of blood within these abnormal vessels could provide a novel method for the ablation of deleterious neovascularization. Thrombin is a serine proteinase that participates in the final stages of the coagulation cascade. An inhibitor of thrombin, p-Amidinophenyl-(E)-4-diethyl- amino-2-hydroxy-α-methylcinnamate hydrochloride, MeCINN (1), covalently attaches to the active site serine hydroxyl, inhibiting or caging, the enzyme. Photolysis of the caged-thrombin in vitro causes a trans-cis isomerization of MeCINN which leads to regeneration of active enzyme and cleaving of fibrinogen into fibrin (6). Using a rabbit model of corneal neovascularization, we found that light at 366 nm safely and effectively photoactivates intravenous caged-thrombin and produces localized thrombosis in vivo. These results suggest that intra- vascular photoactivation of caged-thrombin could be used to occlude abnormal blood vessels in the human eye.

Sleep and diabetic retinopathy

PURPOSE

To investigate the association between sleep duration and diabetic retinopathy (DR).

METHODS

A population-based cross-sectional study using a nation-wide, systemically stratified, multistage, clustered sampling method included a total of 1670 subjects aged ≥40 years with diabetes who participated in the Korean National Health and Nutrition Examination Survey during 2008-2012. All participants performed standardized interviews, including self-reported sleep duration, and comprehensive ophthalmic examinations. Seven standard retinal fundus photographs were obtained from both eyes after pupil dilatation. Diabetic retinopathy (DR) was graded and classified as any DR and vision-threatening DR. Participants were stratified into men and women.

RESULTS

The mean sleep duration was 6.71 hr/day. In men, adjusted OR of any DR was 1.88 [95% confidence interval (OR), 1.01-3.59] in those with ≤5 hr sleep, and 2.19 (95% CI, 1.01-4.89) in those with ≥9 hr sleep, compared to in subjects with 6-8 hr sleep, after adjusting for potential confounders including age, body mass index (BMI), diabetes duration, fasting glucose level, haemoglobin A1c levels and hypertension. In women, however, no significant association between sleep duration and DR was found. The vision-threatening DR was not significantly associated with sleep duration in either men or women.

CONCLUSIONS

Short and long sleep was associated with high prevalence of DR in men. Sleep deprivation may be involved in the pathogenesis of DR development.

Scleral Buckling in the Treatment of Retinal Detachment Due to Retinal Dialysis

BACKGROUND AND OBJECTIVE

To describe clinical features and outcomes of scleral buckle surgery as treatment for patients with rhegmatogenous retinal detachment caused by retinal dialysis.

PATIENTS AND METHODS

Nonrandomized, consecutive case series. All patients underwent encircling scleral buckle for retinal detachment secondary to retinal dialysis. Visual acuity (VA) and retinal attachment status were recorded for the postoperative period.

RESULTS

The study included 16 eyes of 15 patients with mean age 25.8 years; 80% were male, and 75% of the cases were associated with trauma. Dialyses were most commonly found inferotemporally (63%). Mean preoperative VA was 20/103 and mean postoperative VA was 20/62. VA improved in nine cases, and eight cases had a VA of 20/40 or better at the last follow-up. Due to retinal re-detachment, two patients (13%) required additional surgery with vitrectomy.

CONCLUSIONS

Retinal dialysis is an uncommon etiology for retinal detachment and is often associated with trauma and younger age. Scleral buckling can be an effective strategy in the initial management of these patients.

Positive Association between Blood 25-Hydroxyvitamin D Levels and Pterygium after Control for Sunlight Exposure

Purpose

To investigate the association between blood 25-hydroxyvitamin D levels and pterygium.

Methods

Korean National Health and Nutrition Examination Survey 2008–2011 were used for the present epidemiologic study. A total of 19,178 participants aged ≥ 30 years were evaluated for blood 25-hydroxyvitamin D levels and performed ophthalmic slit lamp examinations. Pterygium was considered as a growth of fibrovascular tissue over the cornea.

Results

The average blood 25-hydroxyvitamin D levels were 18.6 ng/mL, and prevalence of pterygium was 6.5%. The odds of pterygium significantly increased across blood 25-hydroxyvitamin D quintiles after controlling sun exposure time as well as other confounders such as sex, age, smoking, diabetes, hypertension (P < 0.001). The odds ratios (OR) for pterygium was 1.51 (95% Confidence Interval[95%CI]; 1.19–1.92) in the highest blood vitamin D quintile. Stratified analysis by sex showed a positive association between blood 25-hydroxyvitamin D levels and pterygium in both men (quintile 5 versus 1, OR; 1.68, 95%CI; 1.19–2.37) and women (quintile 5 versus 1, OR; 1.37, 95% CI; 1.00–1.88).

Conclusions

Even after controlling sun light exposure time, we found a positive association between blood 25-hydroxyvitamin D levels and pterygium in a representative Korean population. The mechanism underlying this association is unknown.

Serum 25-Hydroxyvitamin D Levels and Dry Eye Syndrome: Differential Effects of Vitamin D on Ocular Diseases

Purpose

To investigate associations between serum 25-hydroxyvitamin D levels and dry eye syndrome (DES), and to evaluate the differential effect of vitamin D on ocular diseases including age-related macular disease (AMD), diabetic retinopathy (DR), cataract, and DES.

Methods

A total of 16,396 participants aged >19 years were randomly selected from the Korean National Health and Nutrition Examination Survey. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. DES was defined by a history of clinical diagnosis of dry eyes by a physician. The association between vitamin D and DES was compared to the associations between vitamin D and AMD, DR, cataract, and DES from our previous studies.

Results

The odds of DES non-significantly decreased as the quintiles of serum 25-hydroxyvitamin D levels increased (quintile 5 versus 1, OR = 0.85, 95%CI: 0.55–1.30, P for trend = 0.076) after adjusting for potential confounders including age, sex, hypertension, diabetes, smoking status, and sunlight exposure times. The relative odds of DES (OR = 0.70, 95% CI: 0.30–1.64) and cataract (OR = 0.76, 95% CI: 0.59–0.99) were relatively high, while those of DR (OR = 0.37, 95% CI: 0.18–0.76) and late AMD (OR = 0.32, 95% CI: 0.12–0.81) were lower in men.

Conclusions

The present study does not support an association between serum 25-hydroxyvitamin D levels and DES. The preventive effect of serum 25-hydroxyvitamin D may be more effective for DR and late AMD than it is for cataract and DES.

Care of Older Adults: Role of Primary Care Physicians in the Treatment of Cataracts and Macular Degeneration

This article aims to facilitate optimal management of cataracts and age-related macular degeneration (AMD) by providing information on indications, risk factors, referral guidelines, and treatments and to describe techniques to maximize quality of life (QOL) for people with irreversible vision loss. A review of PubMed and other online databases was performed for peer-reviewed English-language articles from 1980 through August 2012 on visual impairment in elderly adults. Search terms included vision loss, visual impairment, blind, low vision, QOL combined with age-related, elderly, and aging. Articles were selected that discussed vision loss in elderly adults, effects of vision impairment on QOL, and care strategies to manage vision loss in older adults. The ability of primary care physicians (PCPs) to identify early signs of cataracts and AMD in individuals at risk of vision loss is critical to early diagnosis and management of these common age-related eye diseases. PCPs can help preserve vision by issuing aptly timed referrals and encouraging behavioral modifications that reduce risk factors. With knowledge of referral guidelines for soliciting low-vision rehabilitation services, visual aids, and community support resources, PCPs can considerably increase the QOL of individuals with uncorrectable vision loss. By offering appropriately timed referrals, promoting behavioral modifications, and allocating low-vision care resources, PCPs may play a critical role in preserving visual health and enhancing the QOL for the elderly population.

Angiogenic and Inflammatory Vitreous Biomarkers Associated With Increasing Levels of Retinal Ischemia

PURPOSE

To characterize the angiogenic and inflammatory vitreous biomarker profiles in a spectrum of ischemic retinopathies, including neovascular glaucoma.

METHODS

This institutional review board-approved study retrospectively analyzed 80 undiluted vitreous samples obtained during pars vitrectomy. The specimens were frozen (-80°C) and sent for concentration analysis of 34 proteins by Bio-Plex Pro assays. Specimens were divided into four groups: patients undergoing epiretinal membrane (ERM) peeling and/or macular hole (MH) surgery with no history of diabetes (non-DM group), patients undergoing ERM peeling, and/or MH surgery with a history of diabetes (DM group), patients with proliferative diabetic retinopathy (PDR group), and patients with neovascular glaucoma (NVG group). Parametric and nonparametric analyses of demographics and cytokine levels were performed using SPSS.

RESULTS

There were no significant differences in demographics among cohorts. Numerous proteins were significantly elevated between non-DM and DM (G-CSF, sCD40L, Endoglin, IL-6, placental growth factor [PlGF], VEGF-D), DM and PDR (leptin, IL-8, PlGF, VEGF-A), and PDR and NVG (G-CSF, leptin, TIE-2, sCD40L, EGF, HB-EGF, IL-6, IL-8, PlGF, TNF-α). Only PlGF was significantly elevated between each successive cohort. The most potent drivers of NVG were PlGF, VEGF-A, IL-6, and IL-8.

CONCLUSIONS

While the role of angioproliferative growth factors is well documented in ischemic retinopathy, our study delineates the importance of inflammatory and previously underreported angiogenic proteins. It also demonstrates a significant incremental increase in certain factors with increasing levels of ischemia. Both of these findings may guide the development of future therapies for ischemic retinopathies.

A Case Series and Review of Bisphosphonate-associated Orbital Inflammation

PURPOSE

To report the largest series of new cases to date of bisphosphate-associated orbital inflammation.

METHODS

A retrospective case review of patients with orbital inflammation following treatment with systemic bisphosphonate.

RESULTS

Six patients over an 18-month period (2 males, 4 females) with an average age of 62.2 years had onset of orbital inflammatory symptoms 1-11 days after intravenous bisphosphonate infusion or, in 1 case, 4 weeks after initiation of oral bisphosphonate therapy. Imaging revealed diffuse orbital involvement in 3 cases, isolated lateral rectus muscle involvement in 2 cases, and superior rectus-levator involvement in 1 case. Two patients' symptoms resolved spontaneously within 2 weeks, and 3 responded rapidly and completely to corticosteroid therapy. The 1 patient on oral bisphosphonate had a slower but complete response to corticosteroid treatment.

CONCLUSION

Clinicians should be aware of the association between acute orbital inflammation and recent treatment with systemic bisphosphonate medication.

Ocular blast injuries in mass-casualty incidents: the marathon bombing in Boston, Massachusetts, and the fertilizer plant explosion in West, Texas

PURPOSE

To report the ocular injuries sustained by survivors of the April 15, 2013, Boston Marathon bombing and the April 17, 2013, fertilizer plant explosion in West, Texas.

DESIGN

Multicenter, cross-sectional, retrospective, comparative case series.

PARTICIPANTS

Seventy-two eyes of 36 patients treated at 12 institutions were included in the study.

METHODS

Ocular and systemic trauma data were collected from medical records.

MAIN OUTCOME MEASURES

Types and severity of ocular and systemic trauma and associations with mechanisms of injury.

RESULTS

In the Boston cohort, 164 of 264 casualties were transported to level 1 trauma centers, and 22 (13.4%) required ophthalmology consultations. In the West cohort, 218 of 263 total casualties were transported to participating centers, of which 14 (6.4%) required ophthalmology consultations. Boston had significantly shorter mean distances to treating facilities (1.6 miles vs. 53.6 miles; P = 0.004). Overall, rigid eye shields were more likely not to have been provided than to have been provided on the scene (P<0.001). Isolated upper body and facial wounds were more common in West largely because of shattered windows (75.0% vs. 13.6%; P = 0.001), resulting in more open-globe injuries (42.9% vs. 4.5%; P = 0.008). Patients in Boston sustained more lower extremity injuries because of the ground-level bomb. Overall, 27.8% of consultations were called from emergency rooms, whereas the rest occurred afterward. Challenges in logistics and communications were identified.

CONCLUSIONS

Ocular injuries are common and potentially blinding in mass-casualty incidents. Systemic and ocular polytrauma is the rule in terrorism, whereas isolated ocular injuries are more common in other calamities. Key lessons learned included educating the public to stay away from windows during disasters, promoting use of rigid eye shields by first responders, the importance of reliable communications, deepening the ophthalmology call algorithm, the significance of visual incapacitation resulting from loss of spectacles, improving the rate of early detection of ocular injuries in emergency departments, and integrating ophthalmology services into trauma teams as well as maintaining a voice in hospital-wide and community-based disaster planning.

Indications and techniques of endoscope assisted vitrectomy

The popularization of ophthalmic endoscopy has been promoted by recent technological advancements that increase the number of indications for endoscopy. These advancements have improved the endoscope's capabilities in its two fundamental surgical advantages: (1) bypassing anterior segment opacities, and (2) visualizing anteriorly positioned structures such as the ciliary bodies and sub-iris space. In this article, the current state of the ophthalmic endoscope is reviewed alongside its growing number of applications in glaucoma, vitreoretinal, and ocular trauma surgery. We describe the role of endoscopy in endocyclophotocoagulation for glaucoma, cyclitic membrane peeling in hypotony, retinal detachment surgery, intraocular foreign body removal, severe endophthalmitis, and pediatric traumatic vitreoretinal surgery. This review examines both the pearls and limitations of the ophthalmic application of endoscopy. In doing so, we hope to provide guidelines for using the endoscope and also to highlight applications of endoscopy that merit further study.

Pharmacokinetic study of vitreous and serum concentrations of triamcinolone acetonide after posterior sub-tenon's injection

PURPOSE

To compare a theoretical pharmacokinetic model of triamcinolone acetonide after posterior sub-Tenon's injection with experimental serum and undiluted vitreous triamcinolone acetonide concentrations obtained during pars plana vitrectomy.

DESIGN

Clinical-practice, prospective, interventional case series study.

METHODS

This study compared computer-modeled triamcinolone acetonide diffusion after posterior sub-Tenon's injection with triamcinolone acetonide levels in experimental undiluted vitreous and serum samples from 57 patients undergoing vitrectomy assessed via mass spectrometry and high-pressure liquid chromatography. At least 5 pairs of samples were collected at each of 7 time points (1 day, 3 days, and 1, 2, 3, 4, and 8 weeks) after triamcinolone acetonide injection, with 6 controls without injection. Cortisol levels were measured in 31 sets of samples.

RESULTS

The theoretical model predicted that triamcinolone acetonide levels in systemic blood, vitreous, and choroidal extracellular matrix would plateau after 3 days at 15 ng/mL, 227 ng/mL and 2230 ng/mL, respectively. Experimental vitreous levels of triamcinolone peaked at 111 ng/mL at day 1, then reached a plateau in the range 15 to 25 ng/mL, while serum triamcinolone levels peaked at day 3 near 35 ng/mL and plateaued near 2 to 8 ng/mL. Serum triamcinolone and cortisol levels were inversely correlated (Spearman -0.42, P = .02).

CONCLUSIONS

The theoretical model predicts efficient delivery of triamcinolone acetonide from the posterior sub-Tenon's space to the extracellular choroidal matrix. The experimental findings demonstrate low levels of serum triamcinolone that alter systemic cortisol levels and higher vitreous levels lasting at least 1 month. Both assessments support trans-scleral delivery of posterior sub-Tenon's triamcinolone.

Apoptosis in diabetic fibrovascular membranes after panretinal photocoagulation

A more complete understanding of the role of apoptosis in the regression of diabetic neovasculature following laser panretinal photocoagulation (PRP) will both elucidate the treatment's therapeutic mechanism and potentially lead to novel treatments for neovascularization associated with proliferative diabetic retinopathy that target apoptotic pathways. Pars plana vitrectomy with fibrovascular membrane delamination was performed on five patients with proliferative diabetic retinopathy, with four having received previous PRP treatment and one no previous laser treatment. Using in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, propidium iodide and hematoxylin-eosin staining, apoptotic cells were identified in the excised membranes. The authors found evidence of cells undergoing apoptosis in all of the excised membranes, with increasing amounts of preoperative PRP associated with an increased number of apoptotic cells per millimeter of membrane. The preliminary data suggest that the decrease in ambient mitogen, initiated by PRP treatment, activates apoptosis in diabetic fibrovascular membranes.

Minocycline inhibition of photoreceptor degeneration

OBJECTIVE

To determine whether systemic minocycline can protect photoreceptors in experimental retinal detachment (RD).

METHODS

Retinal detachment was induced in mice by subretinal injection of sodium hyaluronate, 1.4%. In 1 experiment, mice received daily injections of minocycline (group 1) or saline (group 2). In a second experiment, mice were treated with minocycline or saline beginning 24 hours prior, immediately after, or 24 hours after experimental RD. In both experiments, photoreceptor cell survival and apoptosis were assessed by immunohistochemistry with primary antibodies against photoreceptor cell markers, rod rhodopsin, and cone opsin, and by terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling.

RESULTS

Photoreceptor cell apoptosis was detected at day 1 after experimental RD, with apoptotic cells peaking in number at day 3 and dropping by day 7. Treatment with minocycline significantly reduced the number of apoptotic photoreceptor cells associated with RD when given 24 hours before or even 24 hours after RD.

CONCLUSIONS

Our data suggest that minocycline may be useful in the treatment of photoreceptor degeneration associated with RD, even when given up to 24 hours after RD.

CLINICAL RELEVANCE

Use of minocycline in patients with macula-off RD may prevent photoreceptor apoptosis and glial cell proliferation, improving final visual outcomes.

Modified external needle drainage of subretinal fluid in primary rhegmatogenous retinal detachment: a prospective, consecutive, interventional, single-surgeon study

PURPOSE

We describe surgical outcomes in a single-surgeon, consecutive series of patients who received scleral buckle placement for primary retinal detachment using a modified external needle drainage technique.

METHODS

Eighty-two eyes of 80 patients with primary retinal detachment underwent scleral buckle placement with modified external needle drainage. Preoperative, postoperative, and surgical data were collected. Regression analysis was used to evaluate the association between preoperative clinical data and number of surgeries.

RESULTS

The retinal detachment most commonly involved 41% to 50% of the retina. Seventy-six eyes (92.7%) were repaired after 1 surgical procedure, 98.8%, after 2 procedures, and 100%, after 3 procedures. No preoperative clinical variables were found to be significantly correlated with the number of surgeries performed. Vision improved an average of 0.3 logarithm of the minimal angle of resolution or 3 lines of vision (P < 0.001). One eye (1.2%) developed a localized subretinal hemorrhage at the drainage site that resolved spontaneously.

CONCLUSIONS

The modified external needle drainage technique used during scleral buckle placement appears to be safe and effective in patients with primary retinal detachment.

Amino-acid levels in subretinal and vitreous fluid of patients with retinal detachment

PURPOSE

To compare the concentration of amino acids in subretinal and vitreous fluid of patients with primary rhegmatogenous retinal detachment to that of control vitreous.

METHODS

This prospective, observational study measured amino-acid levels in subretinal fluid of patients undergoing scleral buckle placement (n=20) and vitreous fluid in patients undergoing pars plana vitrectomy (n=5) for primary retinal detachment. Vitreous fluid from patients undergoing vitrectomy for macular hole (n=7) or epiretinal membrane (n=3) served as a control. Subretinal fluid and control vitreous were analysed using high-pressure liquid chromatography. Retinal detachment vitreous was analysed using capillary electrophoresis-laser-induced fluorescence.

RESULTS

Mean levels of glutamate (27.0+/-1.7 microM), aspartate (4.1+/-4.0 microM), and glycine (44.1+/-31.0 microM) in subretinal fluid and glutamate (13.4+/-11.9 microM) in the vitreous were significantly elevated in retinal detachment compared to control vitreous. A significant, positive association was observed between levels of aspartate and glutamate in subretinal fluid (Spearman's correlation coefficient: 0.74, P<0.01). Mean arginine levels did not differ significantly between subretinal fluid and control vitreous. Levels of alanine, tyrosine, valine, isoleucine, leucine, and phenylalanine were significantly lower in subretinal fluid compared to control vitreous (all P<0.01).

CONCLUSIONS

Glutamate levels in subretinal fluid and vitreous of patients with primary retinal detachment is significantly elevated in comparison to control vitreous. This finding lends further support to the hypothesis that elevated glutamate levels may result from ischaemia of the outer retina secondary to retinal detachment.

The manifold actions of statins. Comment on "Effects of systemic administration of simvastatin on retinal circulation, by T. Nagaoka, A. Takahashi, E. Sato, et al. Arch Ophthalmol 124:665-70, 2006

OBJECTIVE

To investigate the effect of systemic administration of simvastatin on the retinal circulation.

METHODS

The effects of systemic administration of simvastatin on the retinal circulation after 90 minutes and after 7 days were studied in a placebo-controlled, double-masked, clinical trial among 12 healthy men. We used laser Doppler velocimetry to measure vessel diameter and blood velocity and calculated the blood flow in retinal arteries and veins. We also measured the intraocular pressure and the plasma nitrite/nitrate levels, the stable end products of nitric oxide metabolism.

RESULTS

There were no significant changes in any retinal circulatory parameters at 90 minutes after administration of simvastatin. Daily administration of simvastatin for 7 days significantly increased blood velocity and blood flow in retinal arteries and veins but did not significantly change vessel diameter. The intraocular pressure significantly decreased at 90 minutes and at 7 days after administration of simvastatin. Simvastatin also significantly increased the plasma nitrite/nitrate levels.

CONCLUSION

Simvastatin induced an increase in blood velocity and blood flow in retinal arteries and veins, increased the plasma nitrite/nitrate levels, and decreased the intraocular pressure, probably through the increase in nitric oxide.

Central serous chorioretinopathy after solid organ transplantation

PURPOSE

To describe the demographic and clinical characteristics of central serous chorioretinopathy (CSC) after solid organ transplantation.

DESIGN

Case series.

PARTICIPANTS

Fifteen patients who presented to the authors with CSC after solid organ transplantation.

METHODS

We performed a retrospective chart review to identify patient demographics and clinical features of disease, including angiographic changes.

MAIN OUTCOME MEASURES

Patterns of CSC. These patterns were compared with type of organ received, demographics, and visual outcome.

RESULTS

We identified 25 eyes of 7 women (46.7%) and 8 men (53.3%) that developed CSC after solid organ transplantation. Patient ages ranged from 27 to 55 years (median, 40). Seven of the 15 patients (46.7%) were Caucasian, including 3 Hispanic patients (20%). Of the 8 remaining patients (53.3%), 2 were African American (13.3%), 2 were Filipino (13.3%), and 4 were Asian (26.7%). The organs received included 13 kidneys (86.7%), 1 liver (6.7%), and 1 heart (6.7%). Systemic hypertension was reported in 14 of 15 patients (93.3%). All patients were receiving systemic immunosuppressive drugs at presentation; 14 of 15 (93.3%) were also receiving systemic corticosteroids. Visual acuity at presentation ranged from 20/20 to counting fingers. Patterns of CSC included (1) geographic or diffuse alterations in the retinal pigment epithelium (5 eyes; 2 bilateral, 1 unilateral), (2) focal CSC (6 eyes, all unilateral), (3) multifocal CSC (6 eyes; 2 bilateral, 2 unilateral), and (4) CSC with bullous retinal detachment (8 eyes, all bilateral). Follow-up, available for 21 affected eyes of 13 patients, ranged from 1 month to 6 years (median, 12 months). Compared with other solid organ transplant recipients at our institutions, renal transplant recipients (P = 0.003), as well as Hispanic and Asian patients (P = 0.05), were more prevalent in this cohort.

CONCLUSION

Central serous chorioretinopathy after solid organ transplantation varies in presentation and severity. Our observations support a role for choroidal vascular compromise in the pathogenesis of this disorder.

Photoreceptor apoptosis in human retinal detachment

PURPOSE

Although photoreceptor cell apoptosis has been demonstrated in various animal models of retinal detachment (RD), little is known about its occurrence in human RD. We sought to determine whether human photoreceptor cells undergo apoptosis in response to primary and recurrent RD.

DESIGN

Prospective, clinical-pathologic, case series.

METHODS

Retinal tissue fragments excised during the course of vitreous surgery for RD and recurrent RD were frozen, cut into 4-mum sections, and analyzed using a TdT-dUTP terminal nick-end labeling assay for cell apoptosis. The onset of patient symptoms was used to estimate the duration of the RD.

RESULTS

There were eight patients with primary RD and four patients with recurrent RD enrolled in this study. Duration of RD ranged from 1 to 180 days in the primary RD group, and 2 to 15 days in the recurrent RD group. All retinal tissue specimens had TUNEL-positive cells localized to the outer nuclear layer of the retina, consistent with the localization of photoreceptor cell bodies. TUNEL-positive cells were first identified at 24 hours, peaked by 2 days, and dropped to a low level by 7 days after RD. Recurrent RD induced a greater number of TUNEL-positive cells/mm(2) in the ONL compared with primary RD at corresponding timepoints after the onset of RD.

CONCLUSIONS

In response to primary and recurrent RD, human photoreceptor cells follow a pattern of apoptosis that is similar to that seen in animal models of RD. This study suggests that photoreceptor cell apoptosis may be one of the causes of reduced vision after RD, especially those that involve the macula. Drugs that inhibit photoreceptor apoptosis may help improve the final visual prognosis of patients with RD.

Retinal biopsy techniques for the removal of retinal tissue fragments

Because retinal tissue normally excised during retinal reattachment repair is usually discarded, safe methods for the removal of retinal tissue from the eye were developed. Two methods are described for the removal of retinal tissue fragments otherwise discarded during vitrectomy for retinal detachment repair: (1) the removal of small oval pieces of retinal tissue associated with horseshoe retinal tears and (2) the removal of larger rectangular pieces of retinal tissue associated with relaxing retinotomies or giant retinal tears. These methods provide the retinal surgeon with some simple and safe methods for the extraction of retinal tissue fragments that would otherwise be discarded at the end of surgery.

Expression of Leukocyte Adhesion Molecules in Human Subfoveal Choroidal Neovascular Membranes Treated with and without Photodynamic Therapy

PURPOSE

The purposes of this study were to investigate the immunostaining of the leukocyte adhesion molecules intercellular adhesion molecule (ICAM)-1 and E-selectin in subfoveal choroidal neovascular membranes (CNVMs) surgically excised from patients with age-related macular degeneration (AMD) and to determine whether prior photodynamic therapy (PDT) alters their immunostaining.

METHODS

The localization of ICAM-1 and E-selectin in 10 subfoveal CNVMs was determined by immunohistochemistry. Membranes were also immunostained for CD31 to assess vascularity.

RESULTS

Significantly higher numbers of CD31-staining vessels per unit membrane area were found in the peripheral regions of the membranes compared with the central regions (P = 0.05). ICAM-1 immunoreactivity in the CNVMs was found predominantly on RPE cells, but also on small vessels in the periphery. ICAM-1 staining was significantly more intense in the peripheral, more cellular areas of the membranes than in the central, more fibrotic regions (P = 0.04). ICAM-1 staining in the periphery of the CNVMs was greater than that in choroidal vessels and the RPE of the normal control eye. ICAM-1 immunostaining grade in peripheral regions of the CNVMs decreased with the increasing number of PDT treatments (P = 0.05). Some of the CNVMs also stained for E-selectin in RPE cells and small vessels in the periphery.

CONCLUSIONS

In subfoveal CNVMs from patients with AMD, there is increased immunostaining for leukocyte adhesion molecules, particularly in the peripheral, more cellular regions where angiogenesis may be ongoing. Increasing numbers of PDT treatments may be associated with decreased ICAM-1 immunostaining in the proliferating edges of the CNVMs.

Preventing retinal detachment-associated photoreceptor cell loss in Bax-deficient mice

PURPOSE

To characterize photoreceptor cell apoptosis and cell loss in a mouse model of experimental retinal detachment (RD), and to use the technology of mouse genetics to study the molecular mechanisms underlying RD-associated photoreceptor degeneration.

METHODS

Retinal detachments were created in adult wild-type and Bax-deficient mice by subretinal injection of 1.4% sodium hyaluronate. At 1, 3, 7, and 28 days after injection, animals were killed, eyes enucleated, and retinal sections studied by histochemistry, immunofluorescence labeling, and confocal microscopy. Rods and cones were labeled, and apoptotic cells were identified with terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Photoreceptor cell apoptosis and cell loss were assessed quantitatively by counting both surviving and TUNEL-positive rods and cones.

RESULTS

TUNEL-positive cells were found within the outer nuclear layer (ONL) of the detached portions of the retina. They were detected in the detached retina on day 1, peaked on day 3, and dropped precipitously after day 7 after RD. Photoreceptor cell loss of both rods and cones followed a similar time course after RD. Moreover, deletion of the proapoptotic gene Bax in a knockout mouse model abolished the RD-associated photoreceptor cell degeneration.

CONCLUSIONS

Apoptosis is a major mechanism leading to photoreceptor cell death after RD. Blockage of the activity of the proapoptotic molecule Bax in a knockout mouse model prevents photoreceptor cell apoptosis and cell loss. These data suggest that the Bax-mediated apoptotic signaling pathway plays a critical role in RD-associated photoreceptor cell death.

Bilateral Candida albicans Endophthalmitis Associated with an Infected Deep Venous Thrombus

BACKGROUND

To describe the clinical and histopathologic findings in a patient with bilateral Candida albicans endophthalmitis due to an infected deep venous thrombus.

CASE

A 43-year-old patient with bilateral Candida albicans endophthalmitis due to an infected central venous thrombus. The patient's ophthalmology and hospital charts were reviewed. Histopathologic sections of the Candida albicans retinal granuloma were examined under light microscopy.

OBSERVATIONS

Our patient had multiple blood cultures positive for Candida albicans owing to an infected subclavicular venous thrombosis. Bilateral Candida albicans endophthalmitis was diagnosed. Bilateral vitrectomy and membrane peeling for macular traction retinal detachments were performed. In the right eye, a large retinal granuloma was excised during surgery to adequately relieve traction on the macula. Vision improved in both eyes after surgery. Histopathologic findings revealed branching hyphae surrounded by giant cells, endothelial cell-lined vascular channels, and inflammatory cells.

CONCLUSIONS

This is the first report of an infected deep venous thrombosis causing bilateral endogenous endophthalmitis. Appropriate management of these patients requires clear differentiation between endogenous chorioretinitis and endophthalmitis. Patients with documented fungemia should have a dilated fundus examination on a regular basis until complete clearance of the infection.

A matched study of primary scleral buckle placement during repair of posterior segment open globe injuries

AIMS

To compare the visual and anatomical outcomes of patients who underwent primary scleral buckle (SB) placement during posterior segment open globe repair with matched control patients who did not undergo primary SB placement.

METHODS

Patients who underwent open globe repair alone or with SB placement at Duke University Eye Center (November 1994-September 1997) and the Massachusetts Eye and Ear Infirmary (July 1993-July 1997) were identified. 19 open globe patients who received primary SB placement were matched with control patients who did not receive a primary SB based on three important prognostic factors: (1) visual grade; (2) zone of injury; and (3) mechanism of injury. The outcomes of interest were: (1) visual outcome; (2) anatomical outcome; (3) subsequent retinal detachment (RD); and (4) number of subsequent surgeries.

RESULTS

Baseline characteristics between the groups were similar. Patients who received primary SB placement had a better final visual grade (p = 0.02), logMAR vision (p = 0.007), and anatomical grade (p = 0.01) compared with control patients. Primary SB patients had an average final vision of 20/270, whereas control patients had an average final vision of hand movement. Primary SB placement also resulted in fewer subsequent RDs (26% versus 53%), but this difference did not reach statistical significance (p = 0.10). There were no complications associated with primary SB placement.

CONCLUSION

Primary SB placement during posterior segment open globe repair may decrease the risk of subsequent RD and improve final visual and anatomical outcome.

Mechanisms in proliferative vitreoretinopathy

The wound-healing paradigm for proliferative vitreoretinopathy has provided numerous avenues for investigation into the pathobiology of the process. The emerging picture is a complex interaction of cytokines, matrix proteins, and metalloproteinases influencing cell behavior and resulting in the formation of undesirable periretinal membranes. It seems unlikely that focusing therapy on one particular target will be sufficient to stop the entire cascade of cellular events leading to proliferative vitreoretinopathy. Rather, multiple adjunctive agents targeted at different stages of the process and given at the appropriate time might be more successful in achieving improved visual outcomes for patients.