Comparative analysis of in-silico tools in identifying pathogenic variants in dominant inherited retinal diseases.

Inherited retinal diseases (IRDs) are a group of rare genetic eye conditions that cause blindness. Despite progress in identifying genes associated with IRDs, improvements are necessary for classifying rare autosomal dominant (AD) disorders. AD diseases are highly heterogenous, with causal variants being restricted to specific amino acid changes within certain protein domains, making AD conditions difficult to classify. Here, we aim to determine the top-performing in-silico tools for predicting the pathogenicity of AD IRD variants. We annotated variants from ClinVar and benchmarked 39 variant classifier tools on IRD genes, split by inheritance pattern. Using area-under-the-curve (AUC) analysis, we determined the top-performing tools and defined thresholds for variant pathogenicity. Top-performing tools were assessed using genome sequencing on a cohort of participants with IRDs of unknown etiology. MutScore achieved the highest accuracy within AD genes, yielding an AUC of 0.969. When filtering for AD gain-of-function and dominant negative variants, BayesDel had the highest accuracy with an AUC of 0.997. Five participants with variants in NR2E3, RHO, GUCA1A, and GUCY2D were confirmed to have dominantly inherited disease based on pedigree, phenotype, and segregation analysis. We identified two uncharacterized variants in GUCA1A (c.428T>A, p.Ile143Thr) and RHO (c.631C>G, p.His211Asp) in three participants. Our findings support using a multi-classifier approach comprised of new missense classifier tools to identify pathogenic variants in participants with AD IRDs. Our results provide a foundation for improved genetic diagnosis for people with IRDs.

Optic inversion of scleral-fixated intraocular lens after vitrectomy with fluid-air exchange: case series and review of the literature.

Lens dislocation is a significant complication after cataract surgery. Scleral fixation of 3-piece intraocular lens provides favorable visual outcome and can spare patients the need for lens exchange. Two patients presented with dislocated 3-piece lenses implanted over 10 years earlier. Both patients underwent pars plana vitrectomy and dropped lens rescue with scleral fixation. Postoperatively, the lens optic was found flipped nearly 90° at the optic-haptic junctions secondary to fluid-air exchange performed during vitrectomy. Both patients underwent intraocular lens exchange with a four point sclera fixated lens. Our study found that air tamponade is better avoided during rescue of old dislocated 3-piece lens implants. Intraocular lens exchange is preferred, when possible, to avoid complications associated with old dislocated lenses. Larger studies are needed to determine the effect of time on dislocated lens implants materials.

Treatment of serpiginous choroiditis with sub-tenon triamcinolone in conjunction with systemic steroids case report.

PURPOSE: To report two cases of serpiginous choroiditis which were treated with sub-Tenon's triamcinolone in conjunction with systemic steroids to control acute and chronic disease progression. Increased success of disease remission has been postulated for sub-Tenon's triamcinolone therapy in conjunct with systemic steroids. METHODS: Retrospective chart review of two serpiginous choroiditis patients who presented at an eye center. Both patients received sub-Tenon's triamcinolone and systemic steroids. Visual acuity and disease course are reported. RESULTS: Both cases of serpiginous choroiditis received sub-Tenon's triamcinolone on presentation and were hospitalized for intravenous corticosteroids and systemic work up. The first patient had been on oral corticosteroids before presentation. Both patients reported same day visual improvement after sub-Tenon's triamcinolone was administered. CONCLUSIONS: These two case reports describe unique clinical scenarios in which sub-Tenon's triamcinolone was used in both the acute and chronic phases of serpiginous choroiditis. Local steroid therapy can be a useful adjunctive therapy when systemic steroids are delayed, contraindicated or intolerable.

Endoscopy-assisted pars plana vitrectomy in retinal detachments associated with anterior proliferative vitreoretinopathy and epiciliary membranes.

BACKGROUND: Proliferative vitreoretinopathy (PVR) is the leading cause of recurrent retinal detachment. Anterior PVR can contribute to recurrent retinal detachment and is often difficult to remove during conventional pars plana vitrectomy. The purpose of this study is to report surgical outcomes of single endoscopy-assisted pars plana vitrectomy (E-PPV) in patients with tractional retinal detachments associated with anterior proliferative vitreoretinopathy and epiciliary membranes. METHODS: Retrospective review of E-PPV between 2017 and 2021 at a tertiary referral center. Inclusion criteria involved adult patients who underwent E-PPV for tractional retinal detachment with anterior PVR and epiciliary membranes. Data collection included patients' demographics, ophthalmic exam findings, and surgical outcomes. A series of independent sample tests of proportion were conducted using a p-value of 0.05 as the threshold for statistical significance. RESULTS: Eighteen out of 55 patients who underwent E-PPV met the inclusion criteria. There were six females (33%) and 12 males (p-value = 0.096). Age ranged between 27 and 82 years old (mean age 52.1 ± 17.3 years). Nine patients (50%) had a history of ipsilateral retinal detachment repair. Single E-PPV success rate was 100% after three months, and 94.4% at the latest follow up visit. Recurrent retinal detachment with posterior PVR occurred in one patient four months after surgery. Cataract progressed in 57% (8/14) of phakic patients, with 63% (5/8) undergoing cataract extraction surgery within the first postoperative year. CONCLUSION: E-PPV enabled epiciliary membrane and anterior PVR visualization and removal. The single E-PPV success rate remained high at the latest follow up visit. E-PPV enabled the preservation of the phakic lens in all study patients. Larger prospective studies are needed on the role of E-PPV in retina surgeries.

Bilateral Cystoid Macular Edema with Zanubrutinib Therapy: A Case Report.

We present a patient with recurrent mantle cell lymphoma (MCL) who was treated with zanubrutinib, a Bruton's tyrosine kinase inhibitor. He subsequently developed bilateral cystoid macular edema (CME) in both eyes. This is the first report of CME in a patient with MCL who was treated with zanubrutinib. CME was refractory to topical corticosteroid therapy, but sub-Tenon's steroid injections and holding off zanubrutinib managed to decrease the CME. Treatment managed to prevent further vision loss but did not restore lost vision. The prompt ophthalmic exam is recommended for patients on zanubrutinib with decreased vision.

Unilateral COVID-19-associated vasculitic central retinal vein occlusion: phlebitis with subhyaloid, intraretinal and subretinal hemorrhages.

PURPOSE: To describe unilateral vasculitic central retinal vein occlusion (CRVO) in a young adult whose vision problems preceding system symptoms of COVID-19 infection. METHODS: Observational clinical case report. RESULTS: A 39-year-old immunocompetent male without prior ocular disease presented for vitreoretinal care complaining of decreasing vision in his right eye for two weeks. Headaches, pharyngitis and coughing began four days after his visual symptoms. COVID-19 testing was negative prior to initial vitreoretinal evaluation and positive afterward. Dilated and tortuous major retinal veins in his right eye had prominent perivascular sheathing. A large subhyaloid hemorrhage spanned the macula. Subretinal hemorrhages were present in areas of sheathing and diffuse nerve fiber layer hemorrhages were arrayed in the distribution of the radial peripapillary capillary plexus. Laboratory tests for inflammatory diseases were negative. The patient was hospitalized for COVID-19 pneumonia a few days after his initial vitreoretinal evaluation. Pars plana vitrectomy was performed for persistent subhyaloid hemorrhage eight weeks after his hospitalization. The visual acuity in the patient's right eye improved from CF to 20/30 post-operatively. CONCLUSION: The patient's findings are consistent with an atypical CRVO which we hypothesize to be of vasculitic origin because of prominent associated retinal phlebitis and venous sheathing. Concomitant subhyaloid, nerve fiber layer and subretinal hemorrhages involved the superficial and deep retinal vascular complexes. The patient's COVID-19-related hospitalization and systemic management delayed surgical management of his subhyaloid hemorrhages but a good visual result was achieved despite persistence of macular preretinal blood for three months.

Endoscopic Pars Plana Vitrectomy in Patients With Open-Globe Injury and Corneal Opacity.

Purpose: To determine the 1-year outcomes of endoscopic pars plana vitrectomy (EPPV) and its impact on the corneal transplantation rate in patients with open-globe injury (OGI) and corneal opacity. Methods: This retrospective cohort study collected data between December 2018 and August 2021. All EPPVs were performed at a level I trauma center. Inclusion criteria were adult patients with a history of OGI complicated by corneal opacification that prevented fundus visualization. The main outcome measures were the rate of successful retinal reattachment, final visual acuity (VA), and number of patients who had penetrating keratoplasty (PKP) within 1 year of the OGI. Results: Ten patients (3 women; 7 men) with a mean age of 63.4 ± 22.7 years (SD) met the inclusion criteria. The indications for EPPV were intraocular foreign bodies in 2 patients, dense vitreous hemorrhage in 3 patients (1 with a retinal tear; 1 with a choroidal hemorrhage), and retinal detachment in 5 patients. The final VA ranged from 20/40 to no light perception. All 4 repaired detachments remained attached after 1 year. Corneal opacity was treated with PKP in 3 patients. Conclusions: Results indicate EPPV can be a useful tool to treat posterior segment pathology in patients with a recent OGI and corneal opacity. EPPV can help address posterior segment disease and postpone corneal transplantation until the visual potential can be fully determined. Larger prospective studies are needed.

Unilateral Episcleritis Following COVID-19 Booster Vaccination of a Crohn's Disease Patient: A Case Report and Review of the Literature.

Purpose: The Coronavirus Disease 2019 (COVID-19) pandemic spurred vaccine development and resulted in the development of the novel mRNA COVID-19 vaccine and with it, a growing public concern of vaccine side effects. There are reports of ocular inflammatory processes such as episcleritis being possible side effects of COVID-19 vaccination. Here we reported the first case of unilateral episcleritis in a Crohn's disease patient following her third mRNA COVID-19 vaccination booster shot. Patient and Methods: A 27-year-old female presented with a 1-day history of right eye redness, itching, and burning. Patient reported developing these symptoms within 3-4 hours after vaccination. Her past medical history was relevant for Crohn's disease. Ophthalmic examination revealed right 2+ conjunctival injection that blanched with phenylephrine drops. Otherwise, her ophthalmic exam was unremarkable. The patient was started on artificial tears and ibuprofen 200 mg three times daily for one week. After one week all symptoms resolved, and ophthalmic examination was back to baseline. Conclusion: This is the first case in the literature of ophthalmic side effects in a Crohn's disease patient after the third mRNA COVID-19 booster. Patients with Crohn's disease may respond differently to booster vaccination. This case report may help healthcare providers when counselling Crohn's disease patients about future COVID-19 mRNA vaccine side effects.

Mycobacterium chimaera chorioretinitis preceding central nervous system lesions: a case report and review of the literature.

BACKGROUND: Mycobacterium chimaera ocular infection is a rare disease that is linked to bypass devices used during cardiothoracic surgeries. Reported cases in the literature of ocular involvement preceding CNS involvement are based on clinical exam with no neuroimaging. Here we present a case of M. chimaera ocular infection with no CNS M. chimaera lesions on brain magnetic resonance imaging (MRI). CASE PRESENTATION: A 59-year-old female presented with altered mental status and blurred vision in February 2021. Her past medical history was significant for aortic valve replacement and ascending aortic aneurysm repair in 2017 complicated by known M. chimaera infection. She had been receiving azithromycin, ethambutol, rifampin, and amikacin as systemic anti-mycobacterium treatment. Her dilated fundus exam showed numerous yellow placoid circular lesions scattered throughout the macula and peripheral retina in both eyes with associated vitritis. Systemic workup, including brain MRI showed no acute infectious lesions. Her infections workup was unremarkable except for a positive toxoplasma IgM, for which she was treated with sulfamethoxazole/trimethoprim. One month later, a head computed tomography showed new numerous scattered round foci of hyperdensity throughout the cerebrum and brainstem thought to be foci of M. chimaera infection. Clofazimine was added per culture and sensitivity. MRI brain 1 month later showed mild decrease in conspicuity and number of these intensities while on anti-mycobacterium treatment. Her cognition had improved at that time as well. She was seen in retina clinic 2 months later where her exam showed similar retinal lesions with no associated vitritis or anterior chamber cell in bilateral eyes, suggesting a lack of active infection. Optical coherence tomography macula showed parafoveal cystoid macular edema bilaterally. She was started on steroidal and non-steroidal anti-inflammatory eye drops. CONCLUSIONS: To the best of our knowledge, this is the first case in the literature to report M. chimaera chorioretinitis with concomitant negative neuroimaging. Chorioretinal M. chimaera lesions should motivate high suspicion of CNS involvement prompting early neurological work up.

Prophylactic Laser Treatment Posterior to Pars Plana Vitrectomy Sclerotomy Wounds During Macular Surgery.

Introduction: Sclerotomy related retinal breaks (SRRBs) are a risk factor for postoperative retinal detachment (RD). Endolaser posterior to sclerotomy wounds decreased the risk of SRRBs after 20G pars plana vitrectomy (PPV) for macular disease. However, similar data do not exist for 25G and 23G wounds. Methods: A retrospective cohort study of patients after 23G and 25G PPV for macular pathology was conducted between August 2017 and August 2020. The primary outcome was the postoperative rate of SRRBs or RDs. The secondary outcome was the postoperative rate of pupillary dysfunction and neurotrophic keratopathy. All participants had a minimum postoperative follow-up of one year. Results: One hundred seventeen patients were included in the study (62 in the laser group and 55 in the control group). Mean age was 65.4 ± 11.3 years (56.4% female and 43.6% male). Most of the laser group underwent 23G PPV (90%) while most of the control group underwent 25G PPV (96%). One patient in the control group developed RD secondary to a SRRB. No SRRBs or RDs developed in the laser group. None of the secondary outcomes developed in either group after one year. Conclusions: To the best of the authors' knowledge, this is the first report in the literature on prophylactic laser posterior to small gauge sclerotomies (25G and 23G) during macular surgery. Laser treatment posterior to small gauge sclerotomies (25G and 23G) had a similar incidence of SRRBs as with 20G sclerotomies. Larger prospective studies are needed to further understand the role of laser in lowering SRRB risk.

Uveo-meningeal syndrome secondary to Herpes Simplex Virus related acute retinal necrosis.

PURPOSE: To present a rare case of uveo-meningeal syndrome secondary to herpes simplex virus (HSV-1) in a patient with acute retinal necrosis. OBSERVATIONS: A 49-year-old female with a past medical history of herpes simplex encephalitis 18 years prior presented with a 3-day history of right sided headache and decreased vision of the right eye. Her visual acuity was 20/30 in the right eye and 20/20 in the left eye. Clinical examination revealed right relative afferent pupillary defect, panuveitis, and retinal necrosis. Examination of the left eye was unremarkable. Cerebral spinal fluid (CSF) analysis by polymerase chain reaction (PCR) was negative for herpes simplex virus 1 (HSV-1) but did reveal pleocytosis consistent with meningitis. The patient was admitted and empirically treated with intravenous acyclovir (10 mg/kg every 8 hours) and systemic steroids. Topical steroids and cycloplegia were also started. Magnetic resonance imaging revealed no leptomeningeal, pachymeningeal, or parenchymal enhancement. Systemic autoimmune and infectious workup were unremarkable. Based on clinical exam findings and negative PCR results, an anterior chamber tap was performed with aqueous fluid PCR testing which revealed 71,000 copies of HSV-1. A repeat lumbar puncture was performed on day three of admission and revealed a decrease in pleocytosis after initiation of acyclovir therapy and remained negative for HSV on PCR testing. She was discharged home on intravenous acyclovir, topical steroids, and topical cycloplegics. Her retinal necrotic lesions continued to regress and her headaches continued to improve. CONCLUSIONS AND IMPORTANCE: Uveo-meningeal syndromes are a rare clinical entity that involve the uvea, retina, and meninges. This case highlights the importance of aqueous fluid PCR testing despite negative CSF PCR, as it may hasten treatment with antiviral therapies to preserve vision and limit neurologic sequelae.

Unilateral retinopathy post perilesional interferon α2b injections for ocular surface squamous cell carcinoma.

PURPOSE: To describe the clinical course of a patient presenting with unilateral retinopathy after perilesional interferon alpha injections for treatment of ocular surface squamous cell carcinoma. OBSERVATIONS: A patient, who was being treated with interferon alpha for ocular squamous cell carcinoma, presented with new onset decreased vision in her left eye. Upon examination, she was found to have cotton wool spots and retinal hemorrhages in the affected eye. CONCLUSIONS AND IMPORTANCE: Retinopathy is a well-documented side effect of systemic usage of interferon alpha. However, retinopathy has not been well discussed in the scenario of perilesional injections of interferon. It is important for clinicians to monitor for such pathology when using interferon alpha not only systemically, but also locally.

MINIMAL INVASIVE DRAINAGE TECHNIQUE FOR LARGE EXPANDING SUBRETINAL GAS BUBBLE.

PURPOSE: To report a minimally invasive drainage technique for large expanding subretinal gas bubble and conduct a review of the literature. METHODS: Case report, with schematic diagrams and multimodal imaging including fundus photography and spectral domain optical coherence tomography. Controlled drainage of large subretinal gas bubble using a 30-gauge needle introduced through cryotherapy-treated area in office-based setting. RESULTS: Forty-year-old male patient presented with bullous rhegmatogenous retinal detachment and had gas inadvertently injected into the subretinal space during cryo-pneumatic retinopexy. After successful drainage of subretinal gas in clinic, 0.3cc of perfluoropropane (C3F8) gas was injected in different quadrants near the attached retina. The macula remained attached on immediate fundus examination. The gas bubbles of fish eggs coalesced into a single large bubble within 1 week. Spectral domain optical coherence tomography showed unremarkable foveal scans. After 45 days, the gas bubble completely disappeared, the retina remained attached, and vision in the treated eye was 20/20. CONCLUSION: To the best of our knowledge, this is the first case report of a large expanding gas bubble injected into the subretinal spaces being drained successfully by the described minimal invasive technique. Although it may offer a possible office-based approach to a rare complication, it is generally recommended that surgeons capable of dealing with its possible complications may attempt such technique when immediate vitrectomy is not accessible.

Bilateral Exudative Retinal Detachments Associated with Nivolumab Immunotherapy.

A 58-year-old Caucasian female presented to the retina service with a 2-week history of bilateral decrease in vision. She had stage 4 renal cell carcinoma with osseous metastasis and choroidal metastasis for which she has been treated with Nivolumab immunotherapy. Her exudative retinal detachments resolved after cessation of Nivolumab in association with subtenon steroids (STK) and intravitreal bevacizumab injections. To the best of our knowledge, this is the first report in the literature describing the resolution of Nivolumab-related exudative retinal detachment after early local therapy using STK injections (10 mg), bevacizumab intravitreal injections, and cessation of Nivolumab. We hope by sharing this report to provide new insight into the management of similar patients.

Seronegative ocular toxoplasma panuveitis in an immunocompetent patient.

PURPOSE: Toxoplasma gondii is the most common cause of infectious posterior uveitis worldwide in immunocompetent patients. Despite its prevalence, diagnosis can still be challenging and vision-threatening in cases with atypical presentations. This case exemplifies the importance of clinical exam and additional workup when required despite negative initial serology results. OBSERVATIONS: A 73-year-old immunocompetent woman presented with a 2-year history of recurrent panuveitis and retinal necrosis not responsive to systemic antiviral therapy. Toxoplasma serum antibodies (IgG and IgM) were not detected on systemic workup one year prior. The slit-lamp exam revealed mutton fat keratic precipitates, panuveitis, and necrotic retinal lesions adjacent to a retinal scar. Repeated Toxoplasma serum antibodies (IgG and IgM) were again negative. However, aqueous fluid testing by polymerase chain reaction (PCR) was highly positive for Toxoplasma gondii. The patient improved after starting systemic anti-toxoplasma therapy. CONCLUSION/IMPORTANCE: To our knowledge, this is the first report in the literature of an immunocompetent patient with ocular toxoplasmosis and undetectable serum IgG and IgM. Aqueous fluid PCR testing is useful in suspected ocular toxoplasmosis in patients with vision-threatening lesions despite negative serology.

NONCONFOCAL ULTRA-WIDEFIELD SCANNING LASER OPHTHALMOSCOPY: Polarization Artifacts and Diabetic Macular Edema.

PURPOSE: Bowtie-shaped polarization artifacts are often present in nonconfocal ultra-widefield scanning laser ophthalmoscope (SLO) images. We studied these artifacts and evaluated their potential value as clinical biomarkers in screening for center-involving diabetic macular edema (DME). METHODS: We performed a retrospective, observational, cohort study on 78 diabetic adult patients (143 eyes) who had spectral domain optical coherence tomography and nonmydriatic nonconfocal ultra-widefield SLO testing on the same day. Scanning laser ophthalmoscope green-only (532 nm), red-only (635 nm), and composite pseudocolor (532 plus 635 nm) images were examined for the presence of a foveal bowtie polarization artifact. RESULTS: Polarization artifacts were absent in all but one eye with center-involving DME (32 of 33 eyes). Polarization artifacts were also absent in many eyes without center-involving DME (49 of 110 eyes in pseudocolor images). As clinical biomarkers of center-involving DME, artifact absence has high specificity (99, 100, and 98% for green, red, and pseudocolor images, respectively) but poor sensitivity (49, 31, and 40% for green, red, and pseudocolor images, respectively). CONCLUSION: Foveal bowtie-shaped polarization artifacts occur routinely in nonconfocal ultra-widefield SLO images. Their presence indicates preserved foveal Henle fiber layer structure. Contemporary nonconfocal ultra-widefield SLO images lack the sensitivity for their bowtie artifacts to serve as reliable biomarkers in screening for center-involving DME.

Anterior hyaloid membrane dissection using the conventional surgical microscope: a novel surgical approach in 2 patients.

BACKGROUND: To describe the dissection and removal of the anterior hyaloid membrane using the conventional surgical microscope. CASE PRESENTATION: This microscopic surgical approach involves dissecting the anterior hyaloid at the natural anatomical plane. A 30-gauge needle mounted on a 3.0 cc syringe is used to inject filtered air anterior to the anterior hyaloid membrane. Two patients needed this procedure; the first patient was pseudophakic with proliferative diabetic retinopathy, tractional retinal detachment, and vitreous hemorrhage. The second patient was phakic with proliferative diabetic retinopathy, anterior proliferative vitreoretinopathy, and recurrent vitreous hemorrhage. Both patients tolerated the procedure well with no complications. CONCLUSION: Pneumatic dissection of the anterior hyaloid membrane is previously thought to be only possible with the aid of ophthalmic endoscopy. This novel surgical approach provides surgeons with the option to perform pneumatic dissection of the anterior hyaloid when ophthalmic endoscopy is not available. Prospective studies are needed to reveal possible additional benefits or risks associated with this approach.

Cryotherapy and Pneumatic Retinopexy in Schisis-Related Retinal Detachment.

A 57-year-old female presented with macula-involving retinal detachment secondary to degenerative retinoschisis. She was repaired with transscleral cryotherapy to both inner and outer retinoschisis breaks followed by intravitreal sulfur hexafluoride (SF6) gas injection and anterior chamber paracentesis. Postoperative imaging at 4 months showed preserved fovea and completely attached retina. To the best of the authors' knowledge, this is the first report in the literature treating retinoschisis-related detachment with this minimally invasive technique without subretinal fluid drainage. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:791-794.].

Ocular infarction following ethanol sclerotherapy of an arteriovenous malformation.

PURPOSE: To illustrate a case of ocular infarction following percutaneous ethanol sclerotherapy of an orbital arteriovenous malformation. OBSERVATIONS: The patient is a 31-year-old female who developed ocular infarction of the left eye with light perception vision, proptosis, ophthalmoplegia, and a cherry red spot following sclerotherapy of an orbital arteriovenous malformation. Fluorescein angiography demonstrated decreased arteriolar filling with vascular leakage, indocyanine green angiography showed decreased choroidal perfusion, and optical coherence tomography revealed full thickness retinal edema. Magnetic resonance angiography and venography were negative for venous sinus thrombosis or intracranial vascular compromise. CONCLUSIONS AND IMPORTANCE: Ocular infarction is a rare and devastating disorder that may result in permanent vision loss. Ethanol sclerotherapy has been reported to be effective in treating arteriovenous malformations. To the best of our knowledge, this is the first report in the literature of ocular infarction following percutaneous ethanol sclerotherapy to highlight this disease with multimodal imaging.

Endoscopic vitreoretinal surgery: principles, applications and new directions.

PURPOSE: To analyze endoscopic vitreoretinal surgery principles, applications, challenges and potential technological advances. BACKGROUND: Microendoscopic imaging permits vitreoretinal surgery for tissues that are not visible using operating microscopy ophthalmoscopy. Evolving instrumentation may overcome some limitations of current endoscopic technology. ANALYSIS: Transfer of the fine detail in endoscopic vitreoretinal images to extraocular video cameras is constrained currently by the caliber limitations of intraocular probes in ophthalmic surgery. Gradient index and Hopkins rod lenses provide high resolution ophthalmoscopy but restrict surgical manipulation. Fiberoptic coherent image guides offer surgical maneuverability but reduce imaging resolution. Coaxial endoscopic illumination can highlight delicate vitreoretinal structures difficult to image in chandelier or endoilluminator diffuse, side-scattered lighting. Microendoscopy's ultra-high magnification video monitor images can reveal microscopic tissue details blurred partly by ocular media aberrations in contemporary surgical microscope ophthalmoscopy, thereby providing a lower resolution, invasive alternative to confocal fundus imaging. Endoscopic surgery is particularly useful when ocular media opacities or small pupils restrict or prevent transpupillary ophthalmoscopy. It has a growing spectrum of surgical uses that include the management of proliferative vitreoretinopathy and epiretinal membranes as well as the implantation of posterior chamber intraocular lenses and electrode arrays for intraretinal stimulation in retinitis pigmentosa. Microendoscopy's range of applications will continue to grow with technological developments that include video microchip sensors, stereoscopic visualization, chromovitrectomy, digital image enhancement and operating room heads-up displays. CONCLUSION: Microendoscopy is a robust platform for vitreoretinal surgery. Continuing clinical and technological innovation will help integrate it into the modern ophthalmic operating room of interconnected surgical microscopy, microendoscopy, vitrectomy machine and heads-up display instrumentation.