|Year : 2019 | Volume
| Issue : 1 | Page : 5-8
Microperimetric findings after vitrectomy for dense traumatic vitreous hemorrhage
Nehal M Samy El Gendy
Department of Ophthalmology, Faculty of Medicine, Kasr Al Ainy Medical School, Cairo University, Giza, Egypt
|Date of Web Publication||14-Aug-2019|
Dr. Nehal M Samy El Gendy
43 Gameat El Dewal El Arabia Street, El Mohandeseen District, Giza 12411
Source of Support: None, Conflict of Interest: None
Purpose: The purpose of this study was to evaluate the functional outcome after early and late surgical evacuation of traumatic vitreous hemorrhage (VH) due to blunt trauma. Patients and Methods: Cases who had already undergone pars plana vitrectomy for dense traumatic VH were investigated. Microperimetry (MP) using the OPKO spectral optical coherence tomography (OCT)/scanning laser ophthalmoscopy combination imaging system (OPKO instrumentation, LLC, USA, version 1.89) was done 6–8 months after surgery. Patients were divided into two groups according to the time of surgical interference: patients who were operated upon 6 weeks or less after the onset of hemorrhage (Group A) and patients who had VH for more than 10 weeks before surgery (Group B). Primary outcome included mean and fovea retinal sensitivity (mean retinal sensitivity [MRS], foveal retinal sensitivity [FRS]) and its correlation to timing of surgical interference. Secondary outcome included spectral domain-OCT findings such as epiretinal membrane, subretinal fluid, ellipsoid zone integrity, and central subfoveal thickness. Results: Twenty-three eyes were sorted to Group A and 26 eyes to Group B. The average age was 36.2 ± 3.8 years for Group A, compared to 35.2 ± 3.9 years for Group B (P = 0.4). The average duration of hemorrhage was 27.1 ± 7.3 days for Group A and 60.5 ± 6.7 days for Group B. FRS was significantly higher in Group A (19.2 ± 1.9 dB) compared to 17.7 dB ± 2.4 dB in Group B (P = 0.02). MRS was comparable between the two groups (P = 0.5). FRS and MRS were negatively correlated to duration r = -0.49, P <0.001, r = -0.07, P = 0.61. Conclusion: Delayed surgery affects FRS (6–8 months) after surgery even with the absence of structural changes. Persistence of such changes is recommended to be evaluated by further follow-up.
Keywords: Early vitrectomy, functional outcome, microperimetry, retinal toxicity, traumatic vitreous hemorrhage
|How to cite this article:|
Samy El Gendy NM. Microperimetric findings after vitrectomy for dense traumatic vitreous hemorrhage. Egypt Retina J 2019;6:5-8
| Introduction|| |
The optimum timing for surgical evacuation of vitreous hemorrhage (VH), in the absence of retinal detachment, is still debatable. Some surgeons recommend conservative treatment, deferring surgery to late., However, some recommend early interference, from the fear of iron toxicity effect, missed retinal tears, and retinal detachment development.,
What duration is considered early, and what is believed to be late, is strongly none agreed upon. Traumatic VH due to blunt trauma is not uncommon in adults. Timing depends mainly on the presence of retinal tears.
Color vision and contrast sensitivity was the standard method of quantification of macular function in addition to the best-corrected visual acuity. The introduction of microperimetry (MP) is thought to provide better quantification of macular sensitivity, where point-to-point macular function is tested.,
MP testing can be simultaneously done optical coherence tomography (OCT) imaging using OPKO spectral OCT/scanning laser ophthalmoscopy (SLO) combination imaging system (OPKO instrumentation, LLC, USA, version 1.89). The machine allows real-time tracking of retinal movement and records patient fixation, along with mapping of the macular sensitivity.,
Since vitrectomy for VH timing is still debatable, this study was conducted to correlate duration of VH to macular retinal sensitivity. Also to compare functional and structural outcomes after early (<6 weeks) versus late (more than 10 weeks from the onset of VH) vitrectomies in cases with traumatic VH without retinal detachment using the recently available microperimetric evaluation of the macula.
| Patients and Methods|| |
The study and data collection conformed to all local laws and were compliant with the principles of the Declaration of Helsinki. The study was approved by the local ethics committee. This is an observational cross-sectional study where patients operated upon due to traumatic VH (due to blunt trauma) were investigated for retinal sensitivity using MP. MP and spectral domain (SD)-OCT scan was done 6–8 months post-operative. This was elected to allow for complete healing and subsidence of inflammation. Also to give chance for healing (reversibility) of neurological insult resulted from toxic effect of iron. Age was limited to this group to ensure fair comparison, as it is known that retinal sensitivity decreases with age and since we do not have the base line macular sensitivity before hemorrhage, we opted to select age range (from 30 to 45).
Patients with blunt trauma operated upon due to the development of VH only, with no other complications to blunt trauma, and patients not complicated with retinal detachment at the time of surgery were included.
- Macular diseases discovered after or during surgery including commotio retina and choroidal rupture
- Error of refraction more than six-dimensional (6D)
- Media opacities interfering with scanning as corneal blood staining or opacities
- Diabetic patients
- Patients with retinal vein occlusion.
Enrollment and grouping
Patients with traumatic VH for<6 weeks before pars plana vitrectomy were sorted to Group A, whereas patients who had VH for more than 10 weeks were included in Group B. This group included cases that still needed pars plana vitrectomy after a trial of conservative treatment and also neglected cases. We found that early cases fulfilling the inclusion and exclusion criteria were operated upon in the first 6 weeks. We do not have data about patients operated upon between 6 and 10 weeks.
All cases were operated upon under the same preoperative preparations in well-equipped operative room (OR) units. Twenty-three-gauge pars plana vitrectomy was the standard procedure. Noncontact wide-angle viewing system (binocular indirect ophthalmomicroscope) and the constellation vitrectomy machine (Alcon, Aliso Viejo, CA, USA) were used in all cases.
MP and SD-OCT were done using the OPKO spectral OCT/SLO combination imaging system (OPKO instrumentation, LLC, USA, version 1.89). Pupillary dilatation was done using tropicamide 1% eye drops. The patient was then left in a dark-adapted room for 30 min. The circular polar grid pattern 3°C–12°C was selected with target Goldmann size III. The patients were instructed to fixate on the central target and to push the handheld button whenever a stimulus is seen.
The circular grid consists of 28 dots: 4 central, 12 mid, and 12 outer rings. Stimulus was presented for 200 ms with 1500 ms interval. The system automatically checks for fundus alignment prior to each stimulus presentation.
At the completion of the study, each of 28 retinal test points (or loci) is scored according to the threshold sensitivity detected at that point. The MP value ranges from the lowest sensitivity level, 0 to the highest 20. The mean retinal sensitivity (MRS) was calculated as the average of all measured absolute thresholds expressed in dB. Foveal retinal sensitivity (FRS) was calculated as the average of the central four points from central 2°C.
The OPKO spectral OCT/SLO combination imaging system captures 28,000 A-scans/s. This speed allows the acquisition of up to 128 longitudinal OCT scans in 2 s over a 5-mm area, from which 3D retinal thickness map and a 5 × 5 2D grid can be represented.
The retinal thickness algorithm automatically measures the distance, in micrometers, between the retinal nerve fiber layer and the hyporeflective line above the retinal pigment epithelium, the inner/outer segment junction. No manual adjustment was needed in any case.
SD-OCT-3D retinal thickness map was used to record the mean central foveal thickness. Radial scanning of the retina was done to detect any anatomical abnormalities.
Statistical analysis was carried out using the SPSS® (Statistical Package for the Social Sciences) software version 10. Continuous variables were expressed as mean ± standard deviation. Independent sample t-test was used to test the significance at the univariate level. P<0.05 was considered statistically significant. Chi-square test was used to compare percentages. Visual acuity was converted from Snellen notation to logarithm of the minimum angle of resolution for the purpose of average and standard deviation calculation. Spearman's test was conducted to calculate correlation between FRS and MRS on one hand and duration of surgery from onset of hemorrhage on the other hand.
| Results|| |
The study included 23 cases in Group A and 26 cases in Group B. There was no statistical difference between both the groups as regards the age (P = 0.4). The percentage of males was comparable in both the groups. The percentage of cases with a history of hypertension was comparable in both the groups (P = 0.5). Demographic data are illustrated in [Table 1].
Average duration of hemorrhage was 27.1 ± 7.3 days for Group A and 60.5 ± 6.7 days for Group B.
Six (26.1%) cases in Group A had retinal tears reported during surgery compared to none in Group B (N. B. cases with retinal detachment were excluded from both groups). Seven (30.4%) cases in Group A had subhyaloid hemorrhage compared to 4 (15.4%) cases in Group B.
Spectral domain-optical coherence tomography findings
Cases from both the groups showed no evidence of epiretinal membranes, subretinal fluid, or interruption of the ellipsoid zone or external limiting membrane. Central subfoveal thickness was within normal in all cases.
FRS was significantly higher in Group A compared to Group B (P = 0.02); however, (MRS) was comparable between the two groups. Functional data are summarized in [Table 2].
FRS and MRS were negatively correlated to duration, r = -0.49, P<0.001, r = -0.07, P = 0.61
| Discussion|| |
Surgery for traumatic VH is usually reserved to cases where definite retinal tears or detachment are detected or if the hemorrhage fails to resolve spontaneously after a period of time. Furthermore, patients' own preference and need to return to activity and work early may indicate earlier surgery.
In this study, subtle decrease in RS was found in cases with delayed surgery (more than 10 weeks), shown by decreased mean FRS in spite of comparable MRS and CDVA. FRS was significantly negatively correlated to duration of VH compared to MRS (r = -0.49, P<0.001, r = -0.07, P = 0.61 respectively).
Since the development of MP using the OPKO spectral OCT/SLO combination imaging system, it has been widely used in various retinal and macular diseases;,,,,, however, to our knowledge, this is the first time to be used for the assessment of retinal function after VH.
Group A included cases with retinal tears, whereas Group B did not. This may be explained by the fact that retinal tears could have developed into retinal detachment during this period. Retinal detachment would have changed macular functional and structural outcomes dramatically, that is why eyes with retinal detachment (even with macular sparing) were excluded.
Complications occurring due to persistent VH include hemosiderosis bulbi, retinal damage, glial, and fibrovascular proliferation and glaucoma (either ghost cell or hemolytic). Fibrovascular proliferation and glaucoma pathogenesis are lengthy processes that were not expected to be seen in either of the current research groups. However, as regards retinal toxicity from blood and blood products, it is not yet clear what is considered early and late. Recurrent hemorrhage was not differentiated from persistent hemorrhage. Hypertensive cases could theoretically have recurrent hemorrhage. This is one of the limitations of our study as still it was not known whether old or fresh blood resulted into this difference in FRS.
Internal limiting membrane (ILM) peeling has been proved to affect retinal sensitivity. It has been shown to decrease retinal sensitivity in cases undergoing ILM peeling after primary retinal detachment surgery. In this study, ILM was not done in any of the cases.
With visual acuity as the main parameter compared, it was previously reported that early surgical intervention results in comparable visual outcomes compared to a conservative approach. However, early intervention significantly reduces the incidence of severe vision loss related to macula-off retinal detachment. The study highlighted the risk of development of retinal detachment with late intervention and recommended the need of close follow-up for early detection of retinal detachment that may be missed in dense VH. It was expected that if we included cases developing macula-off retinal detachment, that is expected to occur more in the late group, the results would have been even worse. On the other hand, Guo et al. recommended early vitrectomy to improve curative effect for VH caused by blunt ocular trauma when no improvement was observed after 2–3 weeks of medical treatment. Again, their study depended on visual acuity outcomes and not macular sensitivity. In an experimental study where rabbit eyes were injected with whole blood and hemoglobin, it has been found that despite the fact that the vitreous was almost transparent 8 weeks after hemoglobin injection, still 25% of ferric chloride iron remained in the eye. This may implicate that even cases with a complete resolve of VH have continuous toxic effect on photoreceptors and could be better washed out with surgical interference.
Room illumination may affect the microperimetric results. Mesopic MP tests cone function, whereas dark-adapted MP tests rods and cones. In this study, dark adaptation was the condition for all patients. It would have been interesting to compare mesopic and dark-adapted microperimetric findings between the patients to figure out which photoreceptors are more sensitive to iron.
One of the limitations of this study is the presence of retinal tears only in one group. Debris shed from the torn retina and exposed retinal pigment epithelium may augment toxic effect of blood on the retina. However, this did not affect our results as still FRS was better in Group A compared to Group B.
Another limiting factor is the lack of prolonged follow-up as FRS may improve with time.
| Conclusion|| |
Early vitrectomy to treat uncomplicated traumatic VH results in better FRS, 6–8 months after surgery. We recommend conduction of study with a longer duration follow-up period.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Spraul CW, Grossniklaus HE. Vitreous hemorrhage. Surv Ophthalmol 1997;42:3-9.
Wilkinson CP. What ever happened to bilateral patching? Retina 2005;25:393-4.
Batman C, Cekic O. Preoperative vitreous hemorrhage associated with rhegmatogenous retinal detachment. Graefes Arch Clin Exp Ophthalmol 1997;235:741-2.
Landa G, Su E, Garcia P, Rosen RB. OCT/SLO microperimetry and correlates. In: Microperimetry and Multimodal Retinal Imaging. Berlin, Heidelberg: Springer; 2014. p. 23-39.
Landa G, Rosen RB, Garcia PM, Seiple WH. Combined three-dimensional spectral OCT/SLO topography and microperimetry: Steps toward achieving functional spectral OCT/SLO. Ophthalmic Res 2010;43:92-8.
Crossland MD, Tufail A, Rubin GS, Stockman A. Mesopic microperimetry measures mainly cones; Dark-adapted microperimetry measures rods and cones. Invest Ophthalmol Vis Sci 2012;53:4822.
Zaidman GW, Hong A. Visual and refractive results of combined PTK/PRK in patients with corneal surface disease and refractive errors. J Cataract Refract Surg 2006;32:958-61.
Cappello E, Virgili G, Tollot L, Del Borrello M, Menchini U, Zemella M. Reading ability and retinal sensitivity after surgery for macular hole and macular pucker. Retina 2009;29:1111-8.
Finger RP, Charbel Issa P, Fimmers R, Holz FG, Rubin GS, Scholl HP. Reading performance is reduced by parafoveal scotomas in patients with macular telangiectasia type 2. Invest Ophthalmol Vis Sci 2009;50:1366-70.
Kiss CG, Barisani-Asenbauer T, Simader C, Maca S, Schmidt-Erfurth U. Central visual field impairment during and following cystoid macular oedema. Br J Ophthalmol 2008;92:84-8.
Kriechbaum K, Prager F, Geitzenauer W, Benesch T, Schütze C, Simader C, et al.
Association of retinal sensitivity and morphology during antiangiogenic treatment of retinal vein occlusion over one year. Ophthalmology 2009;116:2415-21.
Varano M, Tedeschi M, Oddone F, Perillo L, Coppè AM, Parravano M. Microperimetric retinal changes in myopic choroidal neovascularization treated with intravitreal ranibizumab. Retina 2010;30:413-7.
Yodoi Y, Tsujikawa A, Nakanishi H, Otani A, Tamura H, Ojima Y, et al.
Central retinal sensitivity after intravitreal injection of bevacizumab for myopic choroidal neovascularization. Am J Ophthalmol 2009;147:816-24, 824.e1.
Eissa MG, Abdelhakim MA, Macky TA, Khafagy MM, Mortada HA. Functional and structural outcomes of ILM peeling in uncomplicated macula-off RRD using microperimetry & en-face OCT. Graefes Arch Clin Exp Ophthalmol 2018;256:249-57.
Melamud A, Pham H, Stoumbos Z. Early vitrectomy for spontaneous, fundus-obscuring vitreous hemorrhage. Am J Ophthalmol 2015;160:1073-70.
Guo XR, Guo HY, Li YS, Tian QF, Dong YL, Zhao ZX, et al.
The surgical timing and effects for vitreous hemorrhage caused by ocular blunt trauma. Zhonghua Yan Ke Za Zhi 2003;39:419-21.
Regnault FR. Vitreous hemorrhage: An experimental study. I. A macroscopic and isotopic study of the evolution of whole blood and hemoglobin. Arch Ophthalmol 1970;83:458-65.1
[Table 1], [Table 2]