Anatomical and functional outcomes of short-term DensironXTRA heavy silicone oil for rhegmatogenous retinal detachments: a comparative case series.

To assess the safety and efficacy of short-term DensironXTRA tamponade for repair of complicated rhegmatogenous retinal detachments (RRD). This is a retrospective consecutive case series of patients undergoing pars plana vitrectomy (PPV) with intravitreal DensironXTRA and a comparator group with gas (sulfur hexafluoride (SF6) or perfluoropropane (C3F8)) tamponades by a single surgeon between January 2017 and November 2020 at a tertiary care centre. A total of 121 eyes with DensironXTRA and 81 comparator eyes with a gas tamponade were included. The DensironXTRA group had a significantly higher number of cases with inferior breaks (82% vs. 48%; p < 0.0001) and a history of previous PPV for RRD (64% vs. 12%; p < 0.0001). DensironXTRA was removed after a median period of 70 (IQR: 48.5-105.5) days. There was similar anatomical success in both the comparator gas tamponade and DensironXTRA groups (98.8% vs. 97.5%, p = 0.6506). Although both groups experienced a significant improvement in visual acuity, this change was significantly higher in the comparator gas tamponade group versus DensironXTRA group (p = 0.0017). There was no significant change in IOP in the DensironXTRA group (mean difference - 0.7; 95% CI - 1.753 to 0.331, p = 0.1785). The rates of complications were low and not significantly different between the two groups. There was no evidence for central macular thinning with DensironXTRA compared to the contralateral eye without RRD as well as with DensironXTRA in situ versus after its removal. DensironXTRA is a promising short-term tamponade agent with good anatomical and functional outcomes and low rates of complications for the repair of complicated RRDs.

What Is a Preferred Retinal Locus?

This review examines the concept of the preferred retinal locus (PRL) in patients with macular diseases. Considering monocular and binocular viewing, we (a) explain how to identify the PRL and discuss the pitfalls associated with its measurement, (b) review the current hypotheses for PRL development, (c) assess whether the PRL is the new reference point of the ocular motor system, and discuss (d) the functional and (e) the clinical implications of the PRL. We conclude that the current definition of the PRL is probably incomplete and should incorporate the need to evaluate the PRL in the framework of binocular viewing. We emphasize the need for more research.

PREOPERATIVE GAS FOR PARS PLANA VITRECTOMY: A SURGICAL TECHNIQUE FOR REPAIR OF RHEGMATOGENOUS RETINAL DETACHMENTS WITH MULTIPLE, LARGE, OR INFERIOR BREAKS.

PURPOSE: To describe the role of preoperative gas for pars plana vitrectomy (PGP) as an adjunct to surgical repair of rhegmatogenous retinal detachment (RRD). METHODS: This is a retrospective consecutive case series of all rhegmatogenous retinal detachments with multiple breaks in more than one quadrant, large breaks extending greater than one clock hour, and/or inferior breaks requiring PPV, who received intravitreal injection of sulfur hexafluoride (SF 6 ) or perfluoropropane (C 3 F 8 ) 1-2 weeks before PPV between 2016 and 2020 at a tertiary care center. RESULTS: A total of 109 eyes underwent the PGP technique, 73% of which had macular involvement. The rhegmatogenous retinal detachments on average involved 5.5 (SD 2.1) clock hours with inferior retinal breaks in 51%. Based on clinical examination, subretinal fluid was noted to be dissipated in parts of the detached retina before PPV in 57% of cases. The use of perfluorocarbon heavy liquid or posterior drainage retinotomy was required in 16% of cases. A 95% primary anatomical success rate was achieved over the median 177 (interquartile range 105-526) follow-up days. A final visual acuity of 20/50 or better was achieved in 65%. CONCLUSION: PGP as an adjunct to PPV may facilitate ease of surgery, as well as anatomical and functional success for rhegmatogenous retinal detachments with multiple, large, and/or inferior breaks.

Binocularity Principles of PRL Development in Patients With Macular Disease.

Purpose: We tested the hypothesis that binocularity requirements for correspondence play a role in establishing the preferred retinal locus (PRL) in macular degeneration. Methods: Monocular PRL locations in 202 eyes of 101 patients with macular degeneration (79 ± 10 years) were recorded with the MP1 microperimeter. Corresponding PRLs were those with similar polar angle and distance from former fovea in the better eye (BE) and the worse eye (WE). Results: On average, the PRL in the BE was in the foveal proximity at 1.1 ± 0.99 degrees for 55 patients (foveal-driven PRL) and eccentrically at 6.9 ± 3.4 degrees for 46 patients with central lesions involving the fovea (peripheral-driven PRL). For the foveal-driven PRL group, the PRL in the BE was not affected by the status of the WE. In 100% of cases, the monocular PRL in the WE was in a corresponding location either on functioning retina or onto the lesion, or would fall onto the lesion during binocular viewing. For the peripheral-driven PRL group, the PRL location depended on the lesion size in both eyes to maximize correspondence and/or the function of peripheral vision during binocular viewing. In this group, PRL correspondence status was different for those with equal, unequal, or extensive lesions in both eyes. Conclusions: Binocularity requirements for correspondence play an important role in determining the PRL location. We formulated two principles based on whether the BE has foveal sparing (foveal-driven PRL) or central lesions affecting the fovea (peripheral-driven PRL). The PRL should be evaluated in the framework of binocular viewing.

Vogt-Koyanagi-Harada disease following influenza vaccination.

Purpose: To report a case of Vogt-Koyanagi-Harada (VKH) disease following influenza vaccination. Observations: A 30-year-old Filipino male developed bilateral pain, redness, photophobia, floaters, headache and tinnitus 2 days after receiving the annual influenza vaccine. He presented to the emergency department 5 days after symptom onset. His past medical and ocular history was unremarkable. His best-corrected distance visual acuity (BCVA) was 20/100 in the right eye (OD) and 20/150 in the left eye (OS). Slit-lamp examination revealed fine keratic precipitates and 1+ anterior chamber cells in both eyes (OU). Dilated fundus examination revealed 1+ vitreous cells with trace haze and multiple serous retinal detachments OU. Magnetic resonance imaging (MRI) of the brain and chest X-ray were unremarkable. Serologic testing was negative for infectious, inflammatory and neoplastic causes. The patient tested positive for HLA-DR4. A diagnosis of acute Vogt-Koyanagi-Harada disease was made and high-dose oral prednisone, intravitreal triamcinolone acetonide and mycophenolate mofetil were needed to achieve quiescence. At 6 months follow-up, our patient remains in remission with no active intraocular inflammation or subretinal fluid. His BCVA has improved to 20/50 OD and 20/30 OS. Conclusion and importance: The annual influenza vaccine may be a trigger for onset or recurrence of VKH in genetically susceptible individuals.

DENSIRON 68 HEAVY SILICONE OIL AS A SHORT-TERM INTRAOCULAR TAMPONADE FOR MACULA-ON INFERIOR RETINAL DETACHMENTS-A CASE SERIES.

PURPOSE: To describe our experience using short-term heavy silicone oil (Densiron 68) for macula-on inferior rhegmatogenous retinal detachments with inferior retinal breaks. METHODS: Retrospective, consecutive, observational case series. Data were retrospectively collected from the medical records of patients who underwent pars plana vitrectomy and Densiron 68 endotamponade for macula-on rhegmatogenous retinal detachment repair. RESULTS: Eight patients were included in the study. The mean patient age was 57.1 ± 12.3 (±SD) years. The mean time to Densiron 68 removal was 57.8 ± 17.8 (±SD) days (ranging from 24 to 83 days). One patient (12.5%) detached three weeks after Densiron 68 removal and required further surgery. All patients were attached at last follow-up with a mean follow-up of 192 days. The mean final best-corrected visual acuity was 20 of 40 (0.29 logarithm of the minimum angle of resolution) similar to the 20 of 45 preoperative best-corrected visual acuity (0.35 logarithm of the minimum angle of resolution, P = 0.501). No significant emulsification was noted before or during the removal of the Densiron 68. Two patients developed an increase in intraocular pressure before Densiron 68 removal that resolved after removal. One patient developed cystoid macular edema that resolved with a short course of topical medications, and one patient had persistent CME that required an intravitreal triamcinolone acetate 1% injection. CONCLUSION: The high anatomic success rate, good visual outcomes, and minimal complications suggest that Densiron 68 can be considered as a short-term tamponade for macula-on retinal detachments with inferior pathology.

Binocular visual function and fixational control in patients with macular disease: A review.

For normally sighted observers, the centre of the macula-the fovea-provides the sharpest vision and serves as the reference point for the oculomotor system. Typically, healthy observers have precise oculomotor control and binocular visual performance that is superior to monocular performance. These functions are disturbed in patients with macular disease who lose foveal vision. An adaptation to central vision loss is the development of a preferred retinal locus (PRL) in the functional eccentric retina, which is determined with a fixation task during monocular viewing. Macular disease often affects the two eyes unequally, but its impact on binocular function and fixational control is poorly understood. Given that patients' natural viewing condition is binocular, the aim of this article was to review current research on binocular visual function and fixational oculomotor control in macular disease. Our findings reveal that there is no overall binocular gain across a range of visual functions, although clear evidence exists for subgroups of patients who exhibit binocular summation or binocular inhibition, depending on the clinical characteristics of their two eyes. The monocular PRL of the better eye has different characteristics from that of the worse eye, but during binocular viewing the PRL of the better eye drives fixational control and may serve as the new reference position for the oculomotor system. We conclude that evaluating binocular function in patients with macular disease reveals important clinical aspects that otherwise cannot be determined solely from examining monocular functions, and can lead to better disease management and interventions.

Long-Term Safety and Efficacy of Siluron2000 with Pars Plana Vitrectomy in the Treatment of Patients with Severe Vitreoretinopathy and Chronic Macular Holes.

PURPOSE: Silicone oil intraocular retinal tamponade is a useful adjunct to pars plana vitrectomy (PPV) in the treatment of complex vitreoretinal conditions. Siluron2000, a modified silicone oil product containing an additional small, high molecular weight and low viscosity, very-long-chain silicone molecule, was developed to reduce post-operative silicone oil emulsification, a non-infrequent complication that occurs with low molecular weight silicone oil. This study was designed to assess the safety and efficacy of long-term Siluron2000. PATIENTS AND METHODS: This was a single-center, retrospective, observational study. All consecutive patients undergoing PPV with intravitreal Siluron2000 injection between January 2017 and September 2019 with at least 6-month follow-up were identified based on billing codes. RESULTS: A total of 57 eyes of 57 consecutive patients comprising 51 cases of proliferative vitreoretinopathy and 6 cases of recurrent full thickness macular hole were included. Median follow-up was 18 months. Emulsification occurred in 9 patients (15%). Retinal re-attachment was achieved in 47 patients (82%). The median time without silicone oil emulsification was 17 months. Of the cases with residual retinal detachment (RD) despite intravitreal Siluron2000, 4 (7%) were total RDs and 6 (10%) were inferior RDs with attached macula. The most common complications were glaucoma 12 (21%), cataract 11 (19%), and epiretinal membrane 2 (3.5%). There was no association between the duration of Siluron2000 and visual outcomes. CONCLUSION: Siluron2000 is an effective long-term tamponade agent in the treatment of complex vitreoretinopathy. Visual and anatomical outcomes are similar to those reported with higher mw silicone oil tamponade agents but with a lower emulsification rate.

Clinical Significance of Macula-Off Rhegmatogenous Retinal Detachment Preoperative Features on Optical Coherence Tomography.

BACKGROUND AND OBJECTIVE: To evaluate the clinical significance of preoperative spectral-domain optical coherence tomography (OCT) features and their association with postoperative outcomes in eyes with primary macula-off rhegmatogenous retinal detachment (RRD). PATIENTS AND METHODS: This is a retrospective case series of all consecutive cases undergoing repair of primary macula-off RRD at two tertiary care academic centers between January 2018 to January 2021. RESULTS: Among 406 eyes, baseline visual acuity (ß = 0.184, P = .001) and time to surgery (ß = 0.009, P = .033) were predictive of postoperative visual acuity at 1-year follow-up after adjusting for age, sex and lens status, as well as presence of preoperative features on OCT such as outer retinal corrugations and height of the retinal detachment. CONCLUSION: Baseline visual acuity and time to surgical repair are the best predictors of vision outcomes following macula-off RRD repair. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:S23-S29.].

Transient Macular Thinning during the Use of Heavy Silicone Oil, Densiron 68.

BACKGROUND: To evaluate the effect of short-term Densiron tamponade on macular thickness. METHODS: Retrospective case series. Data were collected from charts of patients who received short-term (less than 90 days) Densiron tamponade. The OCT parameters were compared between Densiron in situ and after Densiron removal and to the fellow eye. RESULTS: Twenty eyes were included in the analysis. Although there was a trend toward thinner CRT with Densiron in situ in situ the operated eye when compared to the fellow eye (248 and 264 microns, respectively, p = .066), this difference disappeared after DR. At the final OCT there was a statistically significant recovery in the CRT (from 248 to 277 microns, P = .001) and no statistical difference between operated and the fellow eye (p = .265) with no evidence of ERM or CME. CONCLUSIONS: We found transient macular thinning that resolved after Densiron removal with no evidence of long-term macular thinning in eyes treated with Densiron tamponade for retinal detachment.

Effect of Disease Progression on the PRL Location in Patients With Bilateral Central Vision Loss.

Purpose: To investigate the effect of disease progression on the monocular preferred retinal locus (PRL) of the better eye (BE) and worse eye (WE) of patients with central vision loss. Methods: Fifty-one patients with bilateral macular diseases were included. The monocular PRL was recorded for each eye (N = 102 eyes) with the MP-1 microperimeter in two visits that were 458 ± 249 days apart. For each eye and visit, the PRL distance from the former fovea, polar angle, and scotoma size were measured. The change in PRL location from visit 1 to visit 2 was evaluated with the differential map analysis. Results: Scotoma size increased significantly in both eyes. The PRL distance from the former fovea increased significantly from visit 1 to visit 2 in the BE, but not in the WE. The polar angle was relatively stable in both visits for the BE. The change in PRL location in the BE was predicted only by the PRL distance from the former fovea in visits 1 and 2, but not by polar angle or scotoma size. For the WE, the change in PRL location depended on the change in PRL location in the BE, rather than on measurements made on that eye. Conclusions: Disease progression affects monocular PRL location differently in the 2 eyes. The results suggest a recalibration of the oculomotor system with its reference at the PRL from the BE. Translational Relevance: These findings are important for deciding the course of treatment and/or for developing rehabilitation techniques focusing on PRL relocation.

Orbital Magnetic Resonance Imaging Demonstrates Better Contact between the Gas and Anterior Inferior Retina in Side versus Face-Down Position.

PURPOSE: To demonstrate the relationship between an intraocular gas bubble, the retina, and the residual intraocular fluid in different head positions using orbital magnetic resonance imaging (MRI) in 3 patients who underwent pars plana vitrectomy (PPV) with gas tamponade. DESIGN: Novel study. PARTICIPANTS: Patients undergoing PPV with gas-fluid exchange (sulfurhexafluoride [SF6] or perfluoropropane [C3F8]). METHODS: Magnetic resonance imaging scans were obtained in 3 patients undergoing PPV with gas-fluid exchange (SF6 or C3F8). All surgeries were performed by a single surgeon (E.D.M.). On the first postoperative day, the volume of intraocular gas fill was estimated separately by 2 surgeons (A.H. and E.D.M). Four orbital MRI scans were obtained from different head positions, including face up (supine), face down (prone on a massage pillow), flat on the right side, and flat on the left side. MAIN OUTCOME MEASURE: Relationship between the gas bubble and residual vitreous fluid. RESULTS: The MRI images demonstrated, with excellent contrast, the gas and fluid locations in the vitreous cavity in all scans. The relationship between the gas bubble and residual vitreous fluid showed a rapid shift when the patient's head position changed. The MRI images demonstrated that with both 70% gas fill and 95% gas fill, lying on the side can give better support to the inferior retina than face-down positioning. The images demonstrated the importance of accurate head positioning, because a slight change in head position resulted in inadequate contact between the anterior inferior retina and the gas bubble. CONCLUSIONS: To our knowledge, this is the first time that the relationship between an intraocular gas bubble and contact with the retina has been evaluated in different head positions in vivo using MRI imaging. The MRI images demonstrated that side positioning gives better contact between the gas bubble and the inferior and anterior retina than prone positioning even when the gas fill is only 70% of the vitreous cavity.

Effect of Visual Feedback on the Eye Position Stability of Patients with AMD.

The sources of the reduced fixation stability exhibited by patients with central vision loss in the light are relatively well understood, but we have no information on how they control eye position in complete darkness, in the absence of visual error signals. We therefore explored the effect of visual feedback on eye position stability by testing patients with age-related macular degeneration (AMD) and controls with normal vision in the light and in complete darkness. Nine patients (ages 67 to 92 years) and 16 controls (ages 16 to 74 years) were tested binocularly in the light and in complete darkness while remembering the location of a now invisible target. Binocular eye position was recorded with a video-based eye tracker. Results show that eye position stability both in the light and in the dark is worse for patients than for controls and that, for the two groups, eye position stability in the dark is, on average, 5.9 times worse than in the light. Large instability of fixation in patients with AMD was found even in absolute darkness when the scotoma cannot impair vision. These data reflect permanent changes in the oculomotor reference of patients with AMD.

Fixation parameter test-retest repeatability of the worse eye in central field loss.

OBJECTIVE: Patients with bilateral central field loss develop peripheral retinal loci (PRLs) in the functional eccentric retina. PRL characteristics and visual performance in the better-seeing eye (BE) of these patients have previously been reported. In this study, we determined the test-retest repeatability of fixation parameters, including fixation stability, PRL eccentricity, and PRL span in the worse-seeing eye (WE). DESIGN: Retrospective consecutive case series. PARTICIPANTS: Thirty-six patients with bilateral central field loss referred from the Toronto Western Hospital Retina Clinic, who had completed 2 consecutive fixation examinations on the same day. METHODS: Fixation stability was recorded using the Nidek MP-1 microperimeter (Nidek Technologies Srl., Padova, Italy). For each fixation recording, the following parameters were retrieved: (i) 68.2% bivariate contour ellipse area (BCEA), (ii) PRL span (major and minor axes of the BCEA), (iii) PRL meridian (polar angle), and (iv) PRL eccentricity. Test-retest repeatability for each parameter was assessed using Bland-Altman plots to determine 95% limits of agreement. RESULTS: The mean difference between the fixation trial pairs and the 95% limits of agreement for fixation stability, PRL major axis, PRL minor axis, PRL meridian, and PRL eccentricity were 0.06 ± 0.47 log deg2, 0.05° ± 1.42°, 0.07° ± 0.63°, -0.44° ± 66.0°, and -0.23° ±1.56°, respectively. CONCLUSIONS: The fixation parameters in the WE showed robust repeatability, comparable to that of the BE as determined from previous studies. The WE's fixation repeatability should be considered in the interpretation of fixation outcome measures subsequent to treatment interventions.

Image Stabilization in Central Vision Loss: The Horizontal Vestibulo-Ocular Reflex.

For patients with central vision loss and controls with normal vision, we examined the horizontal vestibulo-ocular reflex (VOR) in complete darkness and in the light when enhanced by vision (VVOR). We expected that the visual-vestibular interaction during VVOR would produce an asymmetry in the gain due to the location of the preferred retinal locus (PRL) of the patients. In the dark, we hypothesized that the VOR would not be affected by the loss of central vision. Nine patients (ages 67 to 92 years) and 17 controls (ages 16 to 81 years) were tested in 10-s active VVOR and VOR procedures at a constant frequency of 0.5 Hz while their eyes and head movements were recorded with a video-based binocular eye tracker. We computed the gain by analyzing the eye and head peak velocities produced during the intervals between saccades. In the light and in darkness, a significant proportion of patients showed larger leftward than rightward peak velocities, consistent with a PRL to the left of the scotoma. No asymmetries were found for the controls. These data support the notion that, after central vision loss, the preferred retinal locus (PRL) in eccentric vision becomes the centre of visual direction, even in the dark.

Changes in Fixation Stability with Time during Binocular and Monocular Viewing in Maculopathy.

The purpose of this study was to examine changes in fixation stability over time during binocular and monocular viewing in patients with age-related macular degeneration (AMD). Seventeen patients with AMD and 17 controls were enrolled. Using an EyeLink eyetracker (SR Research Ltd., Mississauga, Ontario, Canada), fixation stability was recorded binocularly and monocularly with each eye for a duration of 15 s while the fellow eye was covered. Fixation stability was analyzed over 3 s intervals for each condition using a 68% bivariate contour ellipse area. Fixation stability did not change with time during binocular viewing for both groups, both monocular conditions for the control group, and monocular viewing with the better eye for the AMD group. However, during monocular viewing with the worse eye, the test of within-subject contrasts showed linear improvement in fixation stability with time (p = 0.016). In conclusion, in patients with AMD, monocular fixational control with the worse eye is poor, but improves with time.

The reading accessibility index and quality of reading grid of patients with central vision loss.

PURPOSE: In this study we evaluated the reading accessibility index (ACC) and a quality of reading grid as assessment tools for reading and as outcome measures for reading rehabilitation of patients with central vision loss. METHODS: Reading performances on the MNRead chart (www.precision-vision.com) were reviewed from our research database. Participants were 24 controls with normal vision [mean age: 34 (SD, 14) years] and 61 patients with bilateral central vision loss [mean age: 81 (SD, 9) years] among which a subgroup of 18 patients [mean age, 76 (SD, 13) years] had undergone perceptual learning training for reading rehabilitation. The outcome measures were maximum reading speed, reading acuity, critical print size, ACC, and the reading quality. A reading quality grid that classified reading speed as spot, slow, functional, or fluent and print size as small, regular, medium, or large was used. All reading speed values were normalised (i.e., divided by 200, the average reading speed in young adults with normal vision measured with the MNRead). RESULTS: The ACC was associated perfectly with the maximum reading speed in the control group (r22  = 0.99, P < 0.001) and strongly with all parameters of reading in the patient group (smallest r value: r59  = -0.66, P < 0.001). For patients with central vision loss, reading was functional for large print, but slow for medium print and spot for regular print. For some patients with the same ACC values, the quality of reading grid revealed important performance differences. For the subgroup (n = 18) of patients who were trained, the ACC revealed a greater effect of training than the other three parameters of reading, and although there were statistically significant improvements across all print size categories, a qualitative improvement in reading was noticed only for the medium print sizes. CONCLUSIONS: The ACC is a good measure of reading performance in patients with central vision loss. Examining reading quality for different print size categories can provide a more detailed picture of reading impairment and should be considered as an outcome for rehabilitation in addition to the ACC.

Failed Pneumatic Retinopexy for Rhegmatogenous Retinal Detachment Repair in Ocular Albinism: Clues to the Role of Melanin in Retinal Pigment Epithelium Pump Function.

The authors report the first case, to their knowledge, of failed pneumatic retinopexy (PR) for rhegmatogenous retinal detachment (RRD) repair in a patient with ocular albinism (OA). The failure of PR to spontaneously resolve the subretinal fluid and reattach the retina in this case is suggestive of a deficiency in subretinal fluid reabsorption by the retinal pigment epithelium (RPE). These findings suggest that in cases of RRD in OA, primary PR should be avoided since this procedure relies on an adequately functioning RPE pump to reabsorb subretinal fluid prior to laser retinopexy. The use of primary vitrectomy or scleral buckling with cryopexy may constitute a more effective strategy for RRD in OA. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:1016-1020.].