Mark Mandelcorn

Internal limiting membrane peeling for decompression of macular edema in retinal vein occlusion: a report of 14 cases.

Background: Currently, there is no proven treatment for macular edema due to central retinal vein occlusion (CRVO). Moreover, not all cases with macular edema due to branch retinal vein occlusion (BRVO) respond to laser photocoagulation. We postulated that internal limiting membrane (ILM) peeling for decompression of macular edema in cases of retinal vein occlusion would facilitate egress of blood and extracellular fluid out of the inner retinal layers, leading to reduction of macular edema and improvement in visual acuity. Methods: Fourteen consecutive patients with macular edema due to CRVO or selected cases of BRVO, not eligible for laser photocoagulation, underwent pars plana vitrectomy with removal of preretinal hyaloid and peeling of the ILM stained with indocyanine green dye. Results: In all cases, intraretinal blood and retinal thickening diminished within 6 weeks of surgery. Visual acuity improved in 78.6% of cases. No surgical complications occurred, although one patient developed nuclear cataract 10 months postoperatively. Conclusion: Pars plana vitrectomy with ILM peeling in selected cases of CRVO and BRVO showed improvement in visual acuity in this nonrandomized, noncontrolled study. This pilot study adds support to the concept that ILM peeling may of visual benefit when compared with the natural history in these vaso-occlusive diseases.

Fixation Stability, Fixation Location, and Visual Acuity after Successful Macular Hole Surgery

PURPOSE This study examined whether changes in fixation stability and fixation location are good predictors of visual acuity after successful macular hole surgery. METHODS Ten patients with macular hole were tested before surgery and at 1 and 3 months after surgery. Visual acuity was measured with the ETDRS; fixation stability and fixation location were assessed with the MP-1 Microperimeter (Nidek Technologies Srl., Vigonza, PD, Italy). The quantitative measure of fixation stability was calculated with a bivariate contour ellipse area (BCEA). Fixation location shift was evaluated using the differential map analysis feature of the MP-1 Microperimeter. RESULTS There was a significant improvement in visual acuity after macular hole closure. Fixation location shifted an average of 0.55 deg and 0.87 deg at 1 month and 3 months after surgery, respectively. The fixation shift was not a good predictor of visual outcome. Fixation stability improved from an average of 0.35 deg(2) before surgery to 0.29 deg(2) at 3 months after surgery. The change in fixation stability (DeltaBCEA = BCEA before - BCEA after surgery) correlated highly with visual outcome. The regression model showed that DeltaBCEA accounted for a significant proportion of the variance in visual acuity both 1 and 3 months after surgery. CONCLUSIONS Some changes in ocular motor function explain the visual outcome after the anatomic success of macular hole surgery. Fixation location shift has no influence on visual acuity post-operatively; however, change in fixation stability is a strong predictor of visual outcome after successful closure of the macular hole.

Fixation Control before and after Treatment for Neovascular Age-Related Macular Degeneration

PURPOSE We studied changes in visual acuity (VA), fixation stability, and location of the preferred retinal locus (PRL) after treatment for unilateral neovascular age-related macular degeneration (AMD) for previously untreated eyes. Concomitant changes in fixation stability, PRL, and VA in the untreated fellow eye were also analyzed. METHODS Pre- and posttreatment tests of visual acuity, fixation stability, and PRL location in both the treated and the untreated eyes were performed on 13 patients undergoing three monthly intravitreal injections of ranibizumab in one eye. RESULTS For the treated eyes there were improvements in VA and fixation stability but no changes in the location of the PRL. No significant changes in any of the three variables were found in the untreated eye. CONCLUSIONS For previously untreated eyes, the improvement in visual acuity after intravitreal ranibizumab injections was accompanied by improvement in fixation stability.

Retinal Arteriolar Hemodynamic Response to a Combined Isocapnic Hyperoxia and Glucose Provocation in Early Sight-Threatening Diabetic Retinopathy

PURPOSE To quantify the magnitude of change of retinal arteriolar hemodynamics induced by a combined isocapnic hyperoxia and glucose provocation in diabetic patients with early sight-threatening diabetic retinopathy (DR) and in age-matched control subjects and to compare the response to that of an isocapnic hyperoxia provocation alone. The study hypothesis was that hyperglycemia reduces the retinal vascular reactivity response to a hyperoxic stimulus. METHODS The sample comprised 17 control subjects (group 1), 15 patients with no clinically visible DR (group 2), 16 patients with mild-to-moderate nonproliferative DR (group 3), and 15 patients with diabetic macular edema (group 4). Retinal hemodynamic measurements were acquired in the subjects, at baseline and 1 hour after consuming a standardized oral glucose load drink while breathing oxygen isocapnic with baseline. RESULTS Retinal blood velocity and flow significantly decreased in all groups (P < or = 0.001 and P < or = 0.0002, respectively) in response to a combined isocapnic hyperoxia and glucose provocation. The maximum-to-minimum velocity ratio significantly increased (P < or = 0.005), and wall shear rate (WSR) significantly decreased (P < or = 0.0002), in groups 1, 2, and 3, but not in group 4. The vascular reactivity response was not significantly different across the groups. The control group demonstrated a reduced change in flow (P = 0.009) and WSR (P = 0.010) to the combined isocapnic hyperoxia and glucose provocation compared with that of hyperoxia alone. CONCLUSIONS The vascular reactivity response to a combined isocapnic hyperoxia and glucose provocation produced a pronounced reduction in blood flow. Unlike the response to hyperoxia alone, the vascular reactivity response was not significantly different across the groups. Hyperglycemia reduced the retinal vascular reactivity response to hyperoxia in age-matched control subjects.

Idiopathic epiretinal membranes: cell type, growth factor expression, and fluorescein angiographic and retinal photographic correlations

BACKGROUND We studied the cellular constituents and the expression of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-beta2) in idiopathic epiretinal membranes (ERMs), attempting to correlate the presence of these growth factors with fluorescein leakage during angiography and with the amount of macular scar tissue. METHODS Idiopathic ERMs were excised at vitrectomy in 41 consecutive cases and stained for glial fibrillary acidic protein (GFAP), vimentin, cytokeratin, desmin and actin. A subset of 13 cases for which fluorescein angiograms and colour retinal photographs were available was further studied for the presence of VEGF and TGF-beta2 in the ERMs, fluorescein leakage and amount of macular scar tissue. RESULTS Of the 41 ERMs, 31 (76%) were found to be fibroglial by light microscopy; 40 (98%) stained for GFAP, 39 (95%) for vimentin, 10 (24%) for cytokeratin, 3 (7%) for desmin and 11 (27%) for actin. Of the 13 ERMs in the subset, staining was positive for VEGF in 11 (85%) and for TGF-beta2 in 11 (85%). There was no statistically significant relationship between the presence of VEGF and leakage (p = 0.68) or between the presence of TGF-beta2 and scar size (p = 0.90). When both VEGF and TGF-beta2 were present, there was likely to be leakage or a large scar, or both, which suggested that an interaction exists between the two growth factors (p = 0.057). When leakage occurred, large scars were 2.5 times less likely to be present; when no leakage occurred, large scars were 2.5 times more likely to be present (odds ratio 0.4; Yules association coefficient -0.43). INTERPRETATION The cells constituting idiopathic ERMs were primarily fibroglial with minimal staining evidence for the presence of contractile proteins in their cytoplasm. VEGF and TGF-beta2 were present in 85% of specimens. Although there was no direct correlation between the presence of these growth factors and either fluorescein leakage or the abundance of scar tissue respectively, there was some evidence for the interaction of these growth factors in producing either leakage or abundance of scar tissue.

High-Resolution Optical Coherence Tomography Retinal Imaging: A Case Series Illustrating Potential and Limitations

Purpose. To present a series of retinal disease cases that were imaged by spectral domain optical coherence tomography (SD-OCT) in order to illustrate the potential and limitations of this new imaging modality. Methods. The series comprised four selected cases (one case each) of age-related macular degeneration (ARMD), diabetic retinopathy (DR), central retinal artery occlusion (CRAO), and branch retinal vein occlusion (BRVO). Patients were imaged using the Heidelberg Spectralis (Heidelberg Engineering, Germany) in SD-OCT mode. Patients also underwent digital fundus photography and clinical assessment. Results. SD-OCT imaging of a case of age-related macular degeneration revealed a subfoveal choroidal neovascular membrane with detachment of the retinal pigment epithelium (RPE) and neurosensory retina. Using SD-OCT, the cases of DR and BRVO both exhibited macular edema with cystoid spaces visible in the outer retina. Conclusions. The ability of SD-OCT to clearly and objectively elucidate subtle morphological changes within the retinal layers provides information that can be used to formulate diagnoses with greater confidence.

Fixation stability as a goal in the treatment of macular disease

Recent advances in the treatment of macular diseases have improved macular anatomy and function as measured and quantified by visual acuity, retinal thickness, and vascular changes detailed by fluorescein angiography. Such observed changes do not always explain improvement in visual function and do not always correlate with patient satisfaction. In some cases, there is poor correlation between anatomic changes and functional improvement. Microperimetry studies on fixation stability after treatment of macular diseases have shown a strong correlation between better fixation stability and visual acuity. Furthermore, achieving better fixation stability facilitates low-vision rehabilitation. These microperimetry findings suggest that fixation stability should be regarded as an important outcome measure in studies of macular disease treatment and should be considered in clinical and research studies of low-vision rehabilitation in cases of treated macular diseases.

Update on pneumatic retinopexy.

Purpose of review Pneumatic retinopexy is an effective, cost-efficient procedure for retinal detachment repair. We review the history, indications, procedure, outcomes, economics, and trends regarding this in-office procedure. Recent findings Pneumatic retinopexy is classically performed in patients with small, superior retinal breaks, but these indications are expanding, with good results. Retinal reattachment rates with pneumatic retinopexy vary from 60% to 91% depending upon patient selection. Pneumatic retinopexy is less costly to perform than scleral buckling and pars plana vitrectomy and avoids many of the complications associated with these procedures. Despite these good results, recent data suggest that the use of pneumatic retinopexy is on the decline. Summary Recent review of the literature and our own personal experience using pneumatic retinopexy in selected cases of retinal detachment indicate that it is an effective and inexpensive procedure that avoids many of the complications that are associated with other retinal reattachment procedures.

A controlled clinical interventional trial comparing 2% chloroprocaine-bupivicaine versus 2% lidocaine- bupivicaine for retrobulbar anesthesia in scleral buckling surgery

OBJECTIVE We undertook this prospective study to compare the relative effectiveness of a bupivicaine mixture with either lidocaine or chloroprocaine for retrobulbar anesthesia in scleral buckling surgery, since chloroprocaine, in some types of nonocular nerve block anesthesia, has been demonstrated to be a more effective nerve block anesthetic. DESIGN This prospective, randomized, double-blind, controlled, clinical, unicentre, interventional trial compared mixtures of lidocaine-bupivacaine with chloroprocaine-bupivacaine in scleral buckling surgery performed by 1 surgeon during a 12-month period. PARTICIPANTS A total of 136 patients who underwent scleral buckling surgery constituted the cases studied. METHODS A total of 31 variables comprising surgical, anesthetic, and patient-centered data were analyzed to determine which drug combination was more efficacious. RESULTS No statistically significant differences were found between chloroprocaine and lidocaine mixtures for retrobulbar anesthesia in scleral buckling surgery from the point of view of the surgeon, anesthetist, or patient. CONCLUSIONS We found no difference in effectiveness for bupivicaine mixed with either lidocaine or chloroprocaine for retrobulbar anesthesia in scleral buckling surgery. Surgeon, anesthetist, and patient-centered data showed no differences in any of the measures studied.

Characteristics of the preferred retinal loci of better and worse seeing eyes of patients with a central scotoma

OBJECTIVE Patients with central vision loss develop preferred retinal loci (PRLs) in the eccentric retina. The characteristics of the PRLs for the better eye (BE) are well studied, but not those of the worse eye (WE). We examined the distribution of monocular PRLs in the visual field (VF), as well as visual acuity, fixation stability, and PRL eccentricity for the BE and WE of patients with central vision loss. DESIGN Retrospective consecutive case series. PARTICIPANTS A total of 87 BE and 50 WE of patients with central vision loss. METHODS Visual acuity, fixation stability, PRL location, and PRL eccentricity measures were retrieved from our database. PRL location was categorized into 5 VF segments: central, superior, inferior, left, and right. RESULTS For BE, PRL frequency distribution was significantly different for the 5 VF segments, χ2(4) = 19.9, p = 0.001. Most PRLs occurred in inferior (31%) and left (31%) VF segments. Visual acuity, fixation stability, and PRL eccentricity depended on the VF segment. Visual acuity correlated with fixation stability and PRL eccentricity. For WE, PRL frequency distribution was not different for the 5 VF segments and visual acuity was not dependent on the VF segment. No relationships between visual acuity and PRL eccentricity or fixation stability were found. CONCLUSIONS Different patterns of PRL characteristics were found for BEs and for WEs. These findings are important to consider when factors such as PRL eccentricity, visual acuity, fixation stability, and PRL location are used as outcome measures after treatment or rehabilitation and when monitoring disease progression.