Vitreoretinal Surgical Techniques Research Articles

Intraocular cysticercosis: clinical characteristics and visual outcome after vitreoretinal surgery

Purpose To report the clinical characteristics of, discuss the surgical options for, and analyze the factors affecting the anatomic and visual outcome of intraocular cysticercosis. Design Retrospective, noncomparative, interventional case series. Participants Forty-five eyes of 44 Indian patients with posterior segment intraocular cysticercosis. Methods The charts of 45 eyes, in which intraocular cysticercosis was removed by vitreoretinal surgery (either transscleral or transvitreal), were reviewed. Main outcome measures These included the postoperative retinal status and the best-corrected Snellen visual acuity. Results Intraocular cysticercosis was present in the vitreous cavity of 27 eyes (60%) and in the subretinal space of 18 eyes (40%). Anterior segment inflammation was seen in 13 eyes (28.8%) and vitreous inflammation in 38 eyes (84.4%). Retinal detachment was observed in 22 eyes (48.8%), with proliferative vitreoretinopathy in 13 eyes (59.09%). Subretinal cysts anterior to the equator (4 eyes) were removed transsclerally, whereas subretinal cysts posterior to the equator and intravitreal cysts (41 eyes) were removed transvitreally. The mean follow-up was 10.5 months. At the last follow-up, the retina was attached in 39 eyes (86.6%); visual acuity of ≥5/200 was achieved in 67.5%. Conclusions Current vitreoretinal surgical techniques enable removal of intraocular cysticercosis in all cases, with reattachment of the retina in 86.6% and recovery of ambulatory vision in approximately 67% of cases.

Retinal detachment in Marfan syndrome: clinical characteristics and surgical outcome.

To describe the clinical characteristics of retinal detachments in patients with Marfan syndrome and report the surgical outcome of vitreoretinal surgery. Records relating to 53 eyes of 45 patients with Marfan syndrome who underwent surgery for rhegmatogenous retinal detachment were reviewed. Of the 53 eyes, 24 (45.3%) underwent scleral buckling as the first procedure and 29 (54.7%) underwent vitrectomy surgery with scleral buckle as the first procedure. Main outcome measures included clinical characteristics of retinal detachment, reattachment rates, and functional improvement in vision. Characteristic findings included total retinal detachment in 40 (75.5%) eyes, atrophic holes in 24 (45.3%) eyes, more than four retinal breaks in 21 eyes (39.6%), preequatorial and postequatorial breaks in 20 (37.7%) eyes, giant retinal tears in six (11.3%) eyes, and proliferative vitreoretinopathy (posterior, anterior, or both) in nine (17%) eyes. In 30 (56.6%) eyes, retinal breaks were located only in the temporal half of the retina. Of the 24 eyes with myopia, 13 (54.2%) had a myopic correction greater than 7 diopters. At the median follow-up of 10.7 months, complete retinal reattachment was obtained in 87.6% and 86.2% of patients undergoing scleral buckling (including additional procedures such as vitrectomy) and vitrectomy surgery, respectively. In eyes with reattached retinas, a final visual acuity of 20/200 or better was obtained in 81% of the patients after scleral buckling and in 56% of the patients after vitrectomy surgery (P = 0.07). Retinal detachment in Marfan syndrome is complete in 75% of the eyes. More than half (56%) the eyes had a retinal break only in the temporal half of the retina, and 83% had at least a break in the temporal half of the retina. Currently available vitreoretinal surgical techniques result in successful reattachment of the retina in approximately 86% of the eyes.

Management of vitreoretinal complications in eyes with permanent keratoprosthesis.

To evaluate the spectrum and treatment of posterior segment complications in eyes that had undergone successful keratoprosthesis (KPro) placement and to determine whether transeyelid vitrectomy techniques could be effectively used in eyes otherwise vulnerable to surface exposure. In the last 10 years, 110 patients received a Dohlman-Doane KPro at the Massachusetts Eye and Ear Infirmary, Boston. We evaluated 22 eyes in 18 patients that required subsequent vitreoretinal surgery to treat posterior segment complications. One surgeon using modified vitreoretinal techniques, as described below, performed all vitreoretinal procedures. The posterior segment complications included 6 cases of retro-KPro membranes, 13 cases of retinal detachments, and 5 cases of isolated vitreous opacity. All 6 retro-KPro membranes were effectively removed by vitrectomy without significant complication and 3 of these patients enjoyed improvement of visual acuity of at least 5 Snellen lines. Of 13 cases of retinal detachment, 6 patients had some improvement in visual acuity, 5 showed no appreciable change, and 2 had some decline in the final visual acuity. In all 5 cases of isolated vitreous opacity, the media was effectively cleared with pars plana vitrectomy. Three patients enjoyed improvement of visual acuity of at least 3 Snellen lines. Four cases of transeyelid vitrectomy were attempted and anatomical success was achieved in all 4 and vision improved in 3 of these patients. No special surgical complications were encountered in any of the 22 eyes as a result of these modified surgical techniques. Best preoperative and postoperative visual acuity and anatomical success were evaluated in relation to the preoperative posterior segment complication. Modified vitreoretinal surgical techniques can be effectively and safely used to treat posterior segment complications in patients with KPro devices. Retro-KPro membranes and other vitreous opacities were the most amenable to treatment. Retinal complications posed a special challenge. However, all of these cases highlight that modified vitrectomy techniques can be used in eyes with permanent KPro devices. These techniques can be performed without additional risk to the eye. Additionally, we demonstrated that transeyelid vitrectomy techniques could be used effectively to manage complications in eyes with severe ocular surface disease without undue exposure of vulnerable tissues.

Cataract surgery in previously vitrectomized eyes.

Because of the application of vitreoretinal surgical techniques to a broader range of posterior segment diseases and because cataract develops frequently in postvitrectomy eyes, cataract surgeons should be familiar with the challenges of cataract extraction in vitrectomized eyes. The cataract surgeon can prepare for these challenges with awareness of such potential factors as an excessively mobile posterior capsule, possible need for vitrectomy equipment, and special considerations concerning intraocular lens selection and power calculation. Knowledge of ocular comorbidities will help the cataract surgeon to counsel the patient appropriately and will help the patient to form realistic expectations. Despite the challenges it presents, cataract extraction in postvitrectomy eyes is usually associated with favorable visual outcomes.

Update on surgical removal of choroidal neovascularization.

Surgical management of choroidal neovascularization may offer patients with subretinal membranes another therapeutic option. Current techniques allow extraction of subretinal membranes, but not all patients have favorable clinical outcomes with such an approach. This article reviews the current state of subretinal surgery and attempts to summarize those characteristics that may predict good surgical results. Vitreoretinal surgical techniques for the management of subretinal membranes are reasonably well established. Certain characteristics of choroidal neovascularization have been identified that may suggest favorable surgical outcomes; however, no randomized prospective data are yet available to show the role of these procedures. The National Institutes of Health-sponsored Submacular Surgery Trials are designed to determine whether surgery or observation is better for eyes with subfoveal choroidal neovascularization in presumed ocular histoplasmosis syndrome or age-related macular degeneration and in eyes with age-related macular degeneration-associated hematomas.

Visual acuity outcomes with and without surgery in patients with persistent fetal vasculature

Purpose To investigate visual acuity outcomes in patients with persistent fetal vasculature (PFV) left untreated or treated with vitreoretinal surgical techniques and to investigate clinical features associated with prognosis. Design Retrospective, noncomparative case series. Participants All patients with PFV examined at the Bascom Palmer Eye Institute from January 1, 1983 through December 31, 1998. Intervention All patients in the study had unilateral PFV. Of 42 PFV patients identified, 30 patients underwent vitreoretinal surgery. Indications for surgery included media opacity (e.g., cataract), vitreoretinal traction, and retinal detachment. Main outcome measures Final best postoperative visual acuity, prognostic ocular clinical features, and surgical complications. Results In the surgical group of patients, median age at diagnosis was 8 weeks, and median length of follow-up was 32 months, with all patients having at least 1 year of follow-up. Two patients had clinical and echographic findings consistent with anterior PFV, 2 patients had strictly posterior PFV, and the remaining 26 patients had components of both anterior and posterior PFV. Fourteen eyes (47%) achieved a final visual acuity of 20/400 or better at last follow-up. Risk factors for a poor visual acuity outcome (<20/400) included microphthalmia (28% of patients with microphthalmia versus 67% of patients with normal axial length achieved a final vision of 20/400 or better; P = 0.061) and preoperative retinal detachment or retinal or optic nerve abnormalities, or both, such as hypoplasia, folds, or indistinct macula with hypopigmentation (25% of patients with any of these anomalies versus 61% of patients without these findings achieved a final vision of 20/400 or better; P = 0.072). After surgery, retinal detachment developed in three eyes, chronic hypotony in two other eyes, and neovascular glaucoma in one eye. In the nonsurgical group there were 6 male and 6 female patients. Two patients with posterior PFV had minimal disease and were not considered surgical candidates, whereas 10 patients with combined anterior and posterior PFV had advanced pathologic features, and it was believed that surgery would not offer significant visual improvement; median age at diagnosis was 9.5 months, and median length of follow-up was 36 months, with all patients having at least 1 year of follow-up. At last follow-up, 3 eyes (25%) had a final visual acuity of 20/400 or better. During follow-up, retinal detachment developed in 2 eyes and chronic hypotony in an additional 2 eyes. Conclusions The current study indicates that approximately 50% of patients undergoing surgery for PFV will achieve useful vision. Visual acuity outcomes in patients with PFV are correlated with the nature and extent of ocular risk factors. Some patients may not be candidates for surgery because of either minimal changes or advanced disease that limit the potential of visual improvement.

Chorioretinal Venous Anastomosis for Central Retinal Vein Occlusion: Transvitreal Venipuncture

The authors describe an eye with a central retinal vein occlusion that developed chorioretinal anastomoses following transvitreal venipuncture, a vitreoretinal surgical technique.

The place of vitreoretinal surgery in the treatment of macular oedema.

Advances in vitreoretinal surgical techniques over the last twenty-five years have expanded the list of indications for vitreoretinal surgical treatment. There are several conditions in which macular oedema is associated with vitreous pathology that is amenable to surgical treatment. This article reviews the role of vitreoretinal surgery in the management of many of these conditions including pseudophakic macular oedema, epiretinal membranes, uveitis, vit-reomacular traction syndrome, and diabetic maculopathy.

Photoreceptor allografts in a feline model of retinal degeneration.

Photoreceptor transplants provide a potential means to restore function in a degenerate retina and/or rescue degenerating host photoreceptors by trophic influences. We have examined photoreceptor allografts in the Abyssinian cat model of hereditary photoreceptor degeneration to determine the viability and influence of such transplants on the host retina. Small pieces of 3- to 5-day-old normal kitten retina containing undifferentiated photoreceptors were injected into the subretinal space of adult Abyssinian cats at an early stage of retinal degeneration using standard vitreo-retinal surgical techniques. The retinas were examined by ophthalmoscopy and fundus photography, then by light and electron microscopy at different times after surgery. Such allografts survive for at least 6 months after surgery. The photoreceptors develop outer segments, invariably in rosettes. The transplants gradually integrate with the host retina but detach the host photoreceptor layer from the retinal pigment epithelium (RPE), which tends to reduce the number of host photoreceptors over the transplant. There is no slowing of the photoreceptor degeneration in neighboring non-detached retina. Inflammation or rejection was not detected. Undifferentiated, neonatal photoreceptor allografts survive and develop outer segments in the subretinal space of the Abyssinian mutant feline retina. The allografts gradually integrate with the host neural retina without inducing rejection. In the vicinity of the transplant there is increased loss of host photoreceptors, considered to be due to their detachment from the RPE layer. There is no evidence of any rescue of host photoreceptors elsewhere in this mutant retina.

Surgical management of posteriorly dislocated silicone plate intraocular lenses.

Silicone plate intraocular lenses do not adhere to the lens capsule and are placed under tension by postoperative contraction of the capsular bag. Recent reports suggest that a defect anywhere in the capsular bag can potentially lead to delayed posterior dislocation of silicone plate intraocular lenses. These implants are more difficult to grasp and manipulate inside the eye than traditional polymethylmethacrylate lenses and therefore, require special microsurgical techniques. Given sufficient anterior capsular support, posteriorly dislocated silicone plate implants can be repositioned in the ciliary sulcus and do not necessarily require intraocular lens exchange. With proper vitreoretinal surgical techniques, posteriorly dislocated silicone plate intraocular lenses can be repositioned or exchanged with excellent visual results and an acceptably low complication rate.

Management of glass intraocular foreign bodies.

To describe the results of management of glass intraocular foreign bodies (IOFBs). A total of 51 eyes of 43 patients that sustained penetrating injury with glass IOFB were studied retrospectively. A total of 23.5% had IOFB only in the anterior segment; the rest had IOFB in the posterior segment alone or in both the anterior and posterior segments. Six eyes were followed conservatively despite IOFB in a functional eye. Removal of IOFB was combined with repair of retinal detachment (where present) using internal tamponade with gas or silicone oil or buckle. After a mean follow-up of 16.8 months, 66.7% of eyes recovered better than 6/60 (20/200) vision and 75.6% had attached retina. On univariate analysis, scleral entry wound, posterior segment IOFB, larger size of IOFB, and retinal damage were found to be associated with poor anatomic outcome. Lower presenting visual acuity, hyphema, retinal damage, subretinal hemorrhage, detached retina, and larger IOFB were associated with a poor functional result. Multivariate analysis identified retinal damage caused by the foreign body as the only factor significantly associated with poor anatomic as well as functional outcome. Glass IOFBs are caused in a majority of cases by blast injury. Bilaterality is not uncommon. Presence of retinal damage is predictive of poor functional and anatomic results. Overall results are modest with modern vitreoretinal surgical techniques.

Submacular surgery for subfoveal choroidal neovascular membranes in patients with presumed ocular histoplasmosis.

To determine the visual results, recurrence rates, and postoperative complications of surgical removal of subfoveal choroidal neovascularization (CNV) in patients with the presumed ocular histoplasmosis syndrome. A consecutive surgical series of 63 eyes of 62 patients with subfoveal CNV and the presumed ocular histoplasmosis syndrome with longer than 6 months of follow-up. Tertiary care university medical center. Patients underwent surgical removal of subfoveal CNV using vitreoretinal surgical techniques. The anatomical and functional results of surgery were analyzed. The median age of the patients was 42 years (range, 16-68 years), and the median follow-up time was 24 months (range, 6-48 months). Visual acuity improved by 2 or more Snellen lines in 22 (35%) of the 63 eyes, was unchanged in 28 (44%) of the eyes, and worsened in 13 (21%) of the eyes. Eleven (17%) of the 63 eyes improved to a visual acuity of 20/50 or better. Eyes with an initial visual acuity of 20/200 or worse had a better prognosis for improved vision (ie, 26 [41%] of the eyes) than those with an initial visual acuity of 20/100 or better (ie, 5 [8%] of the eyes). Recurrence of the subfoveal CNV occurred in 24 (38%) of the 63 eyes and was more common in those eyes that received preoperative laser photocoagulation (ie, 15 [47%] of the eyes). The median time to recurrence was 5 months after surgery. Post-operative complications included macular striae in 4 (6%) of the 63 eyes, rhegmatogenous retinal detachment in 2 (3%) of the eyes, retinal tear in 1 (1.6%) of the eyes, and progression of cataract in 19 (30%) of the eyes. Surgical excision of subfoveal CNV may be an effective therapeutic modality in patients with the presumed ocular histoplasmosis syndrome that offers the possibility of improving central vision in many patients. Factors possibly associated with a favorable visual prognosis include younger patient age and the absence of previous laser photocoagulation.

The efficacy of silicone oil for complicated retinal detachments in the pediatric population.

To evaluate the efficacy of silicone oil as an intraocular tamponade for complicated retinal detachments in the pediatric population. Case series. Referral practice at a major university hospital eye center. Consecutive referred sample of 48 cases of complicated retinal detachments in children 16 years old or younger. Forty-two percent of the patients had traumatic injuries, and 35 of the eyes had undergone at least one previous retinal surgery. The minimum follow-up was 6 months, with an average follow-up of 23 months. Pars plana vitrectomy, silicone oil injection, and advanced vitreoretinal surgical techniques. Successful repair of complicated retinal detachment, improved visual acuity post-operatively, and frequency of complications. The postoperative visual acuity at the last follow-up examination was counting fingers or better in eight (17%) of the 48 cases, and only two eyes saw 20/200 or better. In the 46 eyes in which the retinal status could be determined, 16 retinas (35%) were successfully reattached at last follow-up. Significant complications included corneal opacification (62%) and hypotony (58%). Postoperative glaucoma was not a problem. In the pediatric population with complicated retinal detachments, silicone oil used for intraocular tamponade has disappointing results due to a low rate of sustained retinal reattachment, poor visual rehabilitation, and a high complication rate.

Surgical Management of Subfoveal Choroidal Neovascularization

Subfoveal choroidal neovascularization (CNV) usually is associated with a poor visual prognosis. Laser photocoagulation of certain subfoveal membranes secondary to age-related macular degeneration (ARMD) appears preferable to observation based on recent Macular Photocoagulation Study (MPS) findings but is associated with decreased vision. The authors explored the use of vitreoretinal surgical techniques as an alternative method of eradicating subfoveal CNV. After vitrectomy, a small retinotomy technique was used to extract or disconnect from the choroidal circulation subfoveal CNV in 58 eyes. There were 33 eyes with ARMD, 20 eyes with presumed ocular histoplasmosis, and 5 eyes with miscellaneous etiologies. Five eyes also received subfoveal RPE patches. With limited follow-up, significant improvement in vision (defined as 2 Snellen lines) was achieved in 7 of 22 eyes with ARMD CNV removal (1 eye 20/20), 0 of 4 eyes with ARMD CNV removal and RPE patches, and 1 of 7 eyes with ARMD CNV disconnection. Significant improvement was achieved in 6 of 16 eyes with presumed ocular histoplasmosis removal and 0 of 4 eyes with presumed ocular histoplasmosis CNV disconnection. In 5 eyes with miscellaneous CNV, 2 improved (20/20 and 20/40). CNV recurred in 29%. Some patients with subfoveal CNV appear to benefit from surgical removal. Only rarely do eyes with ARMD improve. Longer-term follow-up and refined case selection are required before this approach can be widely recommended.

Surgical Removal of Subfoveal Neovascularization in the Presumed Ocular Histoplasmosis Syndrome

We treated two patients with presumed ocular histoplasmosis, subfoveal neovascular membranes, and progressive visual acuity loss to 20/400. Vitreoretinal surgical techniques were used to remove the subfoveal membranes. Visual acuity returned to 20/20 with seven months of follow-up in one patient (Case 1) and to 20/40 with three months of follow-up in the other patient (Case 2). No evidence of persistent or current subretinal neovascular membranes in either patient have been noted. These preliminary results suggest that vitreoretinal surgical techniques may be successful in mechanically removing subfoveal neovascular membranes with preservation of overlying neurosensory retina and thus preservation of central visual acuity.