Manoharan Shunmugam

Primary Wegener’s Granulomatosis of the Orbital Apex with Initial Optic Nerve Infiltration

Wegener’s granulomatosis can involve the orbit and sometimes the optic nerve. This usually occurs as a result of contiguous spread from affected sinuses or extraocular muscles, or from a vasculitic posterior optic neuropathy. However, we present an unusual case of isolated orbital apex infiltrative disease in a patient with known Wegener’s granulomatosis. This initially caused painless optic neuropathy and progressed to painful ophthalmoplegia and blindness. Optic nerve biopsy, performed to exclude methotrexate-induced lymphoma, confirmed optic nerve infiltration. The condition was refractory to high-dose pulsed methylprednisolone but the patient gained symptomatic relief from rituximab. Wegener’s granulomatosis should be considered in cases of isolated posterior optic neuropathy, and close attention should be placed on imaging the orbital apex.

Spectral domain optical coherence tomography findings in long-term silicone oil-related visual loss.

Purpose: To investigate spectral domain optical coherence tomography findings in long-term silicone oil–related visual loss. Methods: Four symptomatic patients were reviewed 4 years to 9 years after vitrectomy with silicone oil tamponade for macula-on retinal detachment. Three lost vision with oil in situ, with one at the time of oil removal. Eleven control eyes with good vision were included. Patients underwent assessment of best-corrected visual acuity, contrast sensitivity, Farnsworth-Munsell 100 Hue testing, static perimetry, and spectral domain optical coherence tomography imaging of the macula and disk. Results: Long-term best-corrected visual acuity was significantly reduced in affected eyes (range, 0.44–1.02), as was contrast sensitivity (0.75–1.35) and color discrimination (Farnsworth-Munsell-100 Hue score, 151–390). Static perimetry showed a central scotoma in all affected eyes. Optical coherence tomography revealed microcystic macular changes in the inner nuclear layer of all affected eyes associated with severe loss of the papillofoveal retinal nerve fiber layer. In one patient, serial optical coherence tomography images showed development of microcystic macular changes 18 months after oil removal. Control eyes lacked these features, except two asymptomatic eyes that showed microcystic changes on optical coherence tomography with a corresponding paracentral scotoma. Conclusion: We have demonstrated microcystic macular changes in the inner nuclear layer of affected eyes, as well as focal severe loss of the papillofoveal projection. These changes share significant morphologic features reported in multiple sclerosis–associated optic neuritis and Leber hereditary optic neuropathy.

Air-gas exchange reevaluated: clinically important results of a computer simulation.

PURPOSE The primary aim of this study was to evaluate the efficiency of air-gas exchange techniques and the factors that influence the final concentration of an intraocular gas tamponade. Parameters were varied to find the optimum method of performing an air-gas exchange in ideal circumstances. METHODS A computer model of the eye was designed using 3D software with fluid flow analysis capabilities. Factors such as angular distance between ports, gas infusion gauge, exhaust vent gauge and depth were varied in the model. Flow rate and axial length were also modulated to simulate faster injections and more myopic eyes, respectively. The flush volume of gas required to achieve a 97% intraocular gas fraction concentration were compared. RESULTS Modulating individual factors did not reveal any clinically significant difference in the angular distance between ports, exhaust vent size, and depth or rate of gas injection. In combination, however, there was a 28% increase in air-gas exchange efficiency comparing the most efficient with the least efficient studied parameters in this model. The gas flush volume required to achieve a 97% gas fill also increased proportionately at a ratio of 5.5 to 6.2 times the volume of the eye. CONCLUSIONS A 35-mL flush is adequate for eyes up to 25 mm in axial length; however, eyes longer than this would require a much greater flush volume, and surgeons should consider using two separate 50-mL gas syringes to ensure optimal gas concentration for eyes greater than 25 mm in axial length.

Characteristics Of Rhegmatogenous Retinal Detachment And Their Relationship To Success Rates Of Surgery

Purpose: To determine features of rhegmatogenous retinal detachment predictive of anatomical success with surgical procedure. Methods: All patients undergoing surgery at a tertiary referral practice had contemporaneous data collection in an electronic database. Overall, 847 eyes from 847 patients undergoing surgical procedure for rhegmatogenous retinal detachment were included in this study. Results: Mean age was 62.2 years with 60% male subjects and 56% right eyes. Mean postoperative follow-up was 9.6 months (range, 6 weeks to 10 years). With univariate analysis, the presence of superotemporal breaks was associated with a reduction in the chance of failed primary surgery (P = 0.005); detached inferonasal breaks (P = 0.002), proliferative vitreoretinopathy (PVR) (P < 0.0001), breaks in detached inferior retina (P < 0.0001), fovea off (P = 0.001), and 4-quadrant rhegmatogenous retinal detachment (P < 0.0001) increased the risk of failure. After multivariate analysis PVR, detached inferior breaks, increased number of breaks, and 4-quadrant detachment remained associated with an increased risk of failure, and superotemporal detached breaks with the reduced risk of failure (r2 = 0.08). For patients without PVR, only inferonasal detached breaks and 3 to 4 quadrants of detachment remained predictive of failure (r2 = 0.04). For patients with PVR (n = 120), multivariate analysis showed that PVR C4-12 and posterior breaks increased the failure risk and detached superotemporal breaks reduced the risk of failure (r2 = 0.22). Conclusion: Number of breaks, inferior positioning of breaks, the extent of rhegmatogenous retinal detachment, and PVR are associated with failed primary surgery.

The Pattern and Distribution of Retinal Breaks in Eyes With Rhegmatogenous Retinal Detachment

PURPOSE To identify which presenting features of rhegmatogenous retinal detachment (RRD) suggest the presence of multiple retinal breaks and to ascertain relevant patterns in retinal break location. DESIGN Observational single-center case series. METHODS We collected data from 851 eyes undergoing surgery for RRD between January 2001 and September 2011. Data recorded included patient demographics; extent of RRD; and the size, location, and number of retinal breaks. Statistical regression was used to identify risk factors for the presence of multiple breaks and to analyze patterns in break location. RESULTS Of 851 patients, 7 patients were excluded because of insufficient data. Of 844 patients analyzed, 60% were male. The mean age was 62 years. Three hundred twenty-eight eyes (38.9%) had solitary breaks, whereas 58.8% had breaks in more than 1 quadrant. The superotemporal (ST) quadrant was involved most frequently (582 eyes; 69%). The superonasal and inferotemporal quadrants were involved in 341 (40%) and 274 (32%) eyes, respectively. The inferonasal (IN) quadrant was involved the least frequently (144 eyes; 17%). Of 328 eyes with only 1 break, it was most likely to be in the ST quadrant (182 eyes; 55%) and least likely to be in the IN quadrant (19 eyes; 6%). The risk of having multiple breaks was highest for patients with inferior breaks. Eyes with an IN quadrant break were almost twice as likely to harbor further breaks compared with eyes with an ST quadrant break. Vitreous hemorrhage at presentation was associated with larger breaks. ST quadrant breaks were most likely to be detached (92%), whereas IN quadrant breaks were least likely to be detached (60%). CONCLUSIONS The ST quadrant is the most likely location for retinal breaks, the most frequently involved quadrant in eyes with solitary breaks, and has the highest proportion of detached breaks. By contrast, the IN quadrant is the least likely location for a break, the least frequently involved quadrant in eyes with solitary breaks, and the most likely location for attached breaks. The presence of an inferior (especially IN quadrant) retinal break should raise suspicion that the eye harbors further breaks.

Macular displacement following rhegmatogenous retinal detachment repair

Aims To investigate the incidence of macula displacement and symptoms of distortion following rhegmatogenous retinal detachment (RRD) repair, quantify the displacement where seen and further characterise the nature of the displacement. Methods Consecutive patients undergoing primary RRD repair were assessed postoperatively with fundus autofluorescence and optical coherence tomography imaging, and the extent of macula displacement quantified using a novel means. Findings were examined for correlations with symptoms and pre-operative features. Results Macula displacement was evident postoperatively in 72% of 32 consecutive fovea-involving detachments treated with vitrectomy and gas. It was also evident in 5/17 foveal-sparing cases treated with vitrectomy and gas and in two of two patients with fovea-involving detachments treated with vitrectomy and oil. There was a significant correlation between the presence of macula displacement and symptoms of distortion in the early postoperative period (p=0.013). Symptomatic patients described bending of lines with or without objects appearing smaller or narrower in the operated eye. Quantifying the displacement demonstrated that the extent of displacement was associated with distance from the optic disc (p=0.005) and the extent of retinal detachment. Conclusions Displacement of the macula is common following RRD repair and heterogeneous in nature. Most affected patients are symptomatic in the early postoperative period.

Spectral Domain Optical Coherence Tomography Findings in a Case Series of Patients with Bilateral Diffuse Uveal Melanocytic Proliferation

Bilateral diffuse uveal melanocytic proliferation (BDUMP) is a rare paraneoplastic disorder characterized by bilateral serous retinal detachment with degeneration of the retinal pigment epithelium (RPE). The condition commonly occurs in females with gynecological carcinoma or males with lung malignancy, although several other cancer sites have been described. Furthermore, the condition may occur as the first sign of yet undiscovered malignancy. Our understanding of BDUMP has increased significantly in the last 5 years. Affected patients have recently been shown to possess cultured melanocyte elongation and proliferation (CMEP) factor in the IgG fraction of the serum, explaining the efficacy of plasma exchange in the treatment of the condition. Furthermore, BDUMP-associated dermal and conjunctival melanocytic proliferations have been shown to have minimal malignant potential. Although several authors have reported histological retinal findings in BDUMP, these may be complicated by preparation artifact. We present, for the first time to our knowledge, a mini case series of spectral domain optical coherence tomography (OCT) findings in BDUMP. CASE REPORTS

Morphision: A method for subjective evaluation of metamorphopsia in patients with unilateral macular pathology (i.e., full thickness macular hole and epiretinal membrane)

Background: Lack of clinical tests to quantify spatial components of distortion in patients with full thickness macular holes (FTMH) and epiretinal membranes (ERM). Aim: To develop a test for subjective evaluation of visual distortion in the central visual field around fixation in patients with unilateral FTMH or ERM. Settings and Design: Prospective case-control study carried out at tertiary referral center. Materials and Methods: Twenty-five patients with unilateral macular disease (13 macular epiretinal membranes, 12 full-thickness macular holes), and nine controls (without ocular pathology) underwent ophthalmological examination with logMAR ETDRS visual acuity, near vision and contrast sensitivity assessed. Macular optical coherence tomography and metamorphopsia assessment using Morphision test was also carried out. This test consists of a set of modified Amsler charts for detection, identification, and subjective quantification of visual distortion in the central visual field around fixation. Morphision test content and construct validity, and reliability (test-retest method) were evaluated. Sixteen patients completed an unstructured survey on test performance and preference. Results: Every patient with unilateral FTMH or ERM identified a particular chart using Morphision test (content validity). None of the normal subjects without symptoms of metamorphopsia identified any distortion (construct validity). Test-retest showed a 100% consistency for frequency and 67% for amplitude. The mean amplitude difference between measurements was 0.02 degrees (SD = 0.038). The coefficient of repeatability was 0.075. There was a correlation between Morphision amplitude score and visual acuity and contrast sensitivity, individually. Conclusions: Morphision test allowed detection and subjective quantification of metamorphopsia in the clinical setting in our patients with unilateral macular epiretinal membranes and full thickness macular holes.

Risk factors for visual impairment in patients with sickle cell disease in London.

Purpose Dramatically improved health care in recent years has increased the life expectancy of patients with sickle cell disease (SCD) as well as the prognosis for its ocular complications. We sought to identify risk factors for visual impairment in patients with SCD in London 4 decades after Goldbergs seminal studies. Methods Patients 16 years and older with SCD (genotypes HbSS, HbSC, HbSβ-thalassemia) attending hematology and ophthalmology services were offered ocular examination. Retinopathy was graded according to the Goldberg classification. Visual impairment was defined as corrected distance visual acuity of 20/40 or poorer. Results In total, 182 eyes of 182 patients (mean ± SD age, 37.2 ± 12.8 years; female, 65.9%) were included. Women were significantly older than men (mean ± SD age, 38.8 ± 13.1 vs 34.2 ± 11.8 years; p = 0.0174). There was no difference in mean age of each genotype group (p>0.15). Risk factors for sight-threatening proliferative sickle retinopathy (PSR) were age over 35 years (odds ratio [OR] 2.01; 95% confidence interval [CI] 1.05-3.89; p = 0.0359) and HbSC genotype (OR 4.06; 95% CI 2.07-7.98; p<0.0001). Although visual impairment was related to the presence of sight-threatening PSR (OR 7.23; 95% CI 1.50-35.0; p = 0.0138), it was not related to hemoglobin genotype (p>0.50). Conclusions We present the largest study of ocular findings in SCD in the United Kingdom. Sight-threatening PSR is a risk factor for visual impairment, but hemoglobin genotype status is not.

Characteristics of rhegmatogenous retinal detachments secondary to retinal dialyses.

OBJECTIVE The pattern of retinal features in patients with retinal detachment caused by retinal dialyses is poorly described. The association with trauma has also been inconsistently reported. The authors aim to analyze patient and retinal characteristics in such cases and identify the proportion where trauma is likely causative mechanism. DESIGN Retrospective case series. PARTICIPANTS Sixty-three eyes from 63 patients with retinal detachment secondary to retinal dialysis. METHODS Population was selected from consecutive patients presenting to a single surgeon at a tertiary referral vitreoretinal service (2001-2010). RESULTS Sixty-three patients were identified (4.4% incidence rate). The cohort had a mean age of 32 years with a male preponderance (67%). Seventy-one percent had a single break, 21% had 2 breaks, and 8% had 3 to 7 breaks. Six percent of eyes had dialyses smaller than 0.5 disc diameters. Eighty-one percent of eyes had inferotemporal dialyses, but other quadrants also were involved in 25%, or exclusively in 17.5%. The primary success rate for surgery was 92% (94% final success). The presence of proliferative vitreoretinopathy (PVR) was rare (4 cases) but was a significant factor in failure of retinal reattachment (p < 0.001). Twenty-two percent were regarded as traumatic (93% male; p < 0.05). Other variables were similar between traumatic and nontraumatic eyes. CONCLUSIONS Most retinal dialyses are located inferotemporally; however, multiple dialyses, small dialyses, and dialyses that involve multiple quadrants may be seen. In patients with evidence of direct globe injury, no difference in the pattern of retinal presentation of the dialyses was observed. Although surgical success rates are high, patients with PVR had poor response to surgery.