Mahesh P Shanmugam

Ultrasound biomicroscopy of sclerotomy sites after pars plana vitrectomy for diabetic vitreous hemorrhage.

OBJECTIVE This study was aimed at assessing changes at the sclerotomy site using the ultrasound biomicroscope (UBM) in eyes that underwent primary pars plana vitrectomy for complications of proliferative diabetic retinopathy. DESIGN Prospective, observational case series. PARTICIPANTS Eighty-six eyes of 84 patients with vitreous hemorrhage caused by proliferative diabetic retinopathy. INTERVENTION Three-port pars plana vitrectomy followed by UBM evaluation of all sclerotomy sites between 6 and 8 weeks after surgery. Correlation with intraoperative findings done in case of reoperations. Forty-one eyes had repeat UBM at 6 months. MAIN OUTCOME MEASURES The changes at the sclerotomy site were classified into six groups: well healed, gape, plaque, vitreous incarceration, fibrovascular proliferation, and anterior hyaloidal fibrovascular proliferation (AHFVP). The UBM characteristics of each of the groups were defined. The findings at 6 months were compared with those at 6 to 8 weeks. RESULTS At 6 to 8 weeks after surgery, most sclerotomies were well healed or had either moderate to high reflective plaques bridging the site. Wound gape was seen in 22.1% of active ports, 32.6% of light ports, and 25.6% of infusion ports. Vitreous incarceration was seen most often at the infusion port (18. 6% of eyes). Fibrovascular proliferation was seen in 9.3% of active ports, 12.8% of light ports, and 15.1% of infusion ports. Thirteen eyes had recurrent vitreous hemorrhage 6 to 8 weeks after surgery. Cases with rebleeding and no fibrovascular proliferation at the sclerotomy on UBM did well with outpatient fluid-air exchange (two eyes) or observation only (three eyes). Those with fibrovascular proliferation on UBM (eight eyes) required more extensive surgery. CONCLUSIONS UBM is helpful in detecting complications at the sclerotomy sites after pars plana vitrectomy and is an invaluable tool in the assessment of the patient before reoperation.

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.

Purpose To describe the clinical characteristics of retinal detachments in patients with Marfan syndrome and report the surgical outcome of vitreoretinal surgery. Methods 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. Results 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). Conclusions 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.

Multidrug resistant proteins: P-glycoprotein and lung resistance protein expression in retinoblastoma

Background/aim: Retinoblastoma is the commonest primary intraocular tumour in children. Chemotherapy now plays a big part in the treatment of these tumours. There is not much information about the role of the multidrug resistance proteins (MDR)—P-glycoprotein (P-gp) and vault protein lung resistance protein (LRP)—in retinoblastoma. The authors investigated the expression of P-gp and LRP in retinoblastoma and correlated them clinicopathologically. Methods: Among 60 retinoblastomas, 40 tumours were not subjected to preoperative or postoperative chemotherapy and 20 tumours were subjected to postoperative chemotherapy. In this cohort 27 tumours had no invasion and 33 tumours had invasion of choroid, optic nerve, and orbit. P-gp and LRP expression were studied by immunohistochemistry. Immunoanalysis was done semiquantitatively. Results: Among the 60 tumours P-gp was expressed in 23 (38%) tumours and LRP was expressed in 35 (58%). P-gp was expressed in 11/27 (40%) tumours with no invasion and in 12/33 (36%) tumours with invasion. LRP was expressed in 15/27 (55%) tumours with no invasion and in 20/33 (60%) tumours with invasion. Both P-gp and LRP were negative in three tumours with invasion, which had later developed bone marrow metastasis. There was no correlation between P-gp and LRP expression with invasion, differentiation and laterality of the tumours and response to treatment. Conclusion: Retinoblastoma expresses P-gp and LRP intrinsically before chemotherapy and none of these proteins predicted the response to chemotherapy. Thus, further studies are needed to understand the significance of the expression of the P-gp and LRP proteins in retinoblastoma.

Parabulbar Anesthesia for Primary Vitreoretinal Surgery

PURPOSE The efficacy and safety of parabulbar anesthesia was investigated prospectively in 100 patients undergoing primary vitreoretinal surgery. METHODS The technique involved three steps: (1) orbicularis oculi injection, (2) subconjunctival injection, and (3) sub-Tenon irrigation. The effect of anesthesia was graded 0 to 5 depending on inadequate anesthesia-akinesia with or without local supplementation. Ninety-three patients underwent vitrectomy without buckling and 4 with an encircling band; 3 had scleral buckling. Mean duration of surgery was 89.38 minutes. RESULTS In 69% of patients (grades 4 and 5), no supplementation was required and in 31% (grades 1-3), local supplementation was needed for inadequate anesthesia or akinesia or both. No ocular or systemic complication occurred. Early onset of anesthesia correlated with adequate anesthesia throughout the procedure (P < 0.04). CONCLUSIONS Parabulbar anesthesia is a safe and effective technique of local anesthesia in patients undergoing primary vitreoretinal surgery.

Subretinal fibrosis and nonrhegmatogenous retinal detachment associated with multifocal central serous chorioretinopathy.

Purpose: To report the rare occurrence of subretinal fibrosis in patients with multifocal central serous chorioretinopathy and evaluate the role of systemic corticosteroids and the effects of laser photocoagulation on multifocal leaks. Methods: A total of 29 patients (mean age, 37.7 years; 89.7% male) treated for subretinal fibrosis and multifocal central serous chorioretinopathy from 1983–1995 were reviewed retrospectively. Mean follow up was 26 months (range, 6.8–81 months). Results: Retinal detachment involved the macula in 72.4% cases. Fluorescein angiography showed a mean of 6.7 (range, 2–22) central serous chorioretinopathy leaks and a mean of 1.8 (range, 1–5) retinal pigment epithelial detachments. The fundus pictures of 23 patients who were taking systemic corticosteroids showed no improvement. Following laser treatment, however, retinal reattachment was obtained in all eyes, and improvement in visual acuity of > 2 Snellen lines was noted in 68.9% of patients. Conclusions: The presence of subretinal fibrosis with secondary retinal detachment in otherwise healthy young patients, particularly in men, should alert the physician to look for multifocal central serous retinopathy leaks. Systemic cortiosteroids did not prove effective in treating these patients, although laser treatment is recommended for each leak identified on an angiogram.

Retinoblastoma in adults : Report of three cases and review of the literature

Retinoblastoma usually presents in children younger than 5 years. To our knowledge, 20 cases of retinoblastoma in adults (older than 20 years) have been reported in the literature. Of 173 patients with histopathologically proven retinoblastoma seen in our institute, three were adults. All the patients had endophytic tumors with vitreous seeds. Ultrasonography did not reveal calcification in two cases. Immunohistochemistry with neuron-specific enolase was used to confirm the diagnosis in two cases. All three patients ultimately required enucleation. None of the patients had been referred with a diagnosis of retinoblastoma. The diagnosis of retinoblastoma should be considered in cases of whitish mass lesion in the fundus of an adult.

A Multivariate Analysis of Anatomic Success of Recurrent Retinal Detachment Treated with Pneumatic Retinopexy

PURPOSE The purpose of the study is to determine the success rate of pneumatic retinopexy (PR) after failed scleral buckling and to elucidate the predictors for anatomic failure by multiple logistic regression analysis. METHODS Thirty-six eyes with recurrent retinal detachment after failed scleral buckling underwent PR. Intraocular tamponade was attained with SF6 (20 eyes), C3F8 (13 eyes), and air (3 eyes). Median follow-up was 14 months. RESULTS Retinal reattachment was obtained in 69.4%. Multivariate analysis identified two risk factors for failure: location of retinal break either on the posterior slope or posterior to buckle (P = 0.01) and extent of retinal detachment greater than two quadrants (P = 0.02). CONCLUSIONS Pneumatic retinopexy is an effective alternative to revision surgical operations if the leaking retinal break is located on the buckle.

Management of recurrent retinal detachment in silicone oil-filled eyes.

PURPOSE To report causes of failure, management options, and outcomes after reoperations for recurrent retinal detachment in silicone oil-filled eyes. METHODS One hundred eighteen silicone oil-filled eyes with recurrent retinal detachment were managed with revision of vitrectomy with membrane surgery with or without silicone oil removal, just scleral buckling, or both. Anatomical success was defined as complete reattachment of the retina, and functional success was defined as recovery of ambulatory visual acuity of >or=5/200 at the last follow-up (mean follow-up, 29.7 months). RESULTS In 82.2% of the cases, proliferative vitreoretinopathy was responsible for recurrent retinal detachment in silicone oil-filled eyes. Reoperations without removal of the silicone oil were performed in 65.3% of the cases. Anatomical success occurred in 62.7% of the eyes, and functional success occurred in 52.5%. Silicone oil was removed in 59.5% of the eyes with retinal reattachment; the retina remained attached in 90.9% of the eyes. Predictors of poor anatomical success were presence of posterior diffuse proliferative vitreoretinopathy and combined posterior and anterior proliferative vitreoretinopathy (P <0.02). CONCLUSION Reoperations for recurrent retinal detachment in silicone oil-filled eyes were successful in nearly two thirds of the cases, and over one half of the eyes recovered ambulatory vision.

RPE Atrophy following Photodynamic Therapy in Type 2A Idiopathic Parafoveal Telangiectasis

We report a case of Type 2A idiopathic parafoveal telangiectasis treated by Photodynamic Therapy (PDT), resulting in retinal pigment epithelial (RPE) atrophy corresponding to the size of the laser spot used. This raises a doubt regarding the safety of photodynamic therapy in CNVM secondary to type 2A parafoveal telangiectasis.