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Abstract
Aims To investigate the influence of lag time between the onset of central visual acuity loss and surgical intervention of macula-off retinal detachment.
Methods This retrospective case series examined all consecutively treated eyes with primary macula-off retinal detachment at the University Hospital Hamburg (Germany) from February 2010 to February 2015. Records of 1727 patients operated by six surgeons were reviewed. Eighty-nine eyes (5.2%) from 89 patients met the inclusion and exclusion criteria. The main outcome measure studied was final visual acuity as a function of symptom duration of macula-off detachment. Secondary outcome measures studied were influence of age and surgical technique. Symptom duration was defined as the time from the onset of loss of central vision to surgical intervention.
Results After 10 days no clinically relevant difference was seen in final visual acuity. Eyes with symptom duration of 3 days or less achieved best final visual acuity (p<0.001). Age and preoperative visual acuity had no influence while vitrectomised eyes had better outcome compared with those with scleral buckling.
Conclusions Our study suggests that 1. After 10 days of central visual acuity loss, the final visual outcome is clinically comparable and independent of further delay of surgery up to 30 days. 2. Eyes treated up to 3 days after onset of loss of central vision have better final visual acuity than eyes with longer lag time. However, we did not find statistically significant differences within the first 3 days. 3. Surgery for macula-off retinal detachment may therefore most likely not be postponed without compromising the patient's visual prognosis.
- Treatment Surgery
- Retina
- Rehabilitation
- Vision
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Introduction
Macular detachment has been consistently identified as a negative prognostic indicator for visual recovery after surgical repair of rhegmatogenous retinal detachment (RRD). Several factors such as preoperative visual acuity, height of macular detachment, age, comorbidities and duration of the macular detachment have been found to have an impact on visual outcome.1 ,2
Recently, van Bussel et al3 reviewed articles published from 1995 to October 2013 of patients with macula-off RRD and treated with scleral buckling (SB) or pars plana vitrectomy (PPV). These authors reported a limitation of their study was that there were insufficient data about the final visual acuity (FVA) in patients who received surgery during the first 3 days after onset of central vision loss.
The current study was thus set up to investigate whether eyes treated up to 3 days after macula-off RRD achieved clinically significant better FVA than those with longer lag time between onset of central visual acuity loss and surgical intervention.
Materials and methods
This retrospective case series examined all consecutively repaired eyes with primary macula-off RRD at the University Hospital Hamburg (Germany) from February 2010 to February 2015.
Inpatient and outpatient records including operative notes together with other clinical and demographic data were recorded in a structured database for subsequent analysis. Data collection included age, gender, eye affected, symptom duration, preoperative corrected distance visual acuity (VA), lens status preoperatively and postoperatively, intraoperative and postoperative complications, postoperative VA and follow-up (FU) after 6 months. The main outcome measure studied was FVA as a function of symptom duration of macular detachment. Secondary outcome measures studied were influence of age and surgical technique on FVA. Symptom duration was defined as the time from the onset of loss of central visual acuity to surgical intervention.
All patients analysed in the current study were otherwise ocular healthy patients with no previous history of ocular disease and included in the study only if there was accurate documentation of the onset of loss of central vision to a specific 24 h period. Retreatments or eyes with intraoperative or postoperative complications were not analysed. Further exclusion criteria were FU <6 months, traumatic dialysis or traumatic aetiology of RRD, giant retinal tears, proliferative vitreoretinopathy of grade B or worse, previous ocular surgery in the study or fellow eye and the presence of any condition that may affect visual acuity over time (ie, age-related macular degeneration, diabetic retinopathy, retinal vein occlusion, glaucoma or hereditary retinal dystrophies). All data were anonymised prior to analysis, and this study adhered to the tenets of the Declaration of Helsinki.
Surgery
Eyes were repaired either with PPV alone, phacovitrectomy (PHV) or SB based on the extent of RRD and lens status. Those who underwent PPV were treated with either a 20-gauge, 23-gauge or 25-gauge 3-port PPV, based on the preference of the surgeon. Complete vitrectomy with shaving of the vitreous base was performed in all eyes. All retinal breaks were treated with laser retinopexy or cryopexy. Intraoperative perfluorocarbon, posterior drainage retinotomy or 360° laser was performed in some cases based on the preference of the surgeon. The postoperative tamponade (air, sulphur hexafluoride, hexafluoroethane) was chosen at the discretion of the surgeon. In cases with PHV, cataract surgery was performed using the phacoemulsification technique through a 2.4 mm clear-corneal incision followed by intracapsular implantation of a foldable acrylic posterior chamber intraocular lens (IOL). In all cases, the diameter of the continuous curvilinear capsulorhexis was smaller than the optics of the IOL. Following cataract surgery, a 3-port PPV was performed.
SB involved appropriate exposure of the affected quadrant(s), retinopexy was achieved using cryotherapy followed by either radial or circumferential sponges secured with 4-0 Mersilene sutures. External drainage of subretinal fluid was not routinely performed but when necessary an anterior chamber paracentesis was made to control for any elevation of intraocular pressure as a consequence of tightening the scleral elements. All surgeries were performed under either peribulbar or general anaesthesia.
Statistical analysis
Descriptive statistics for continuous variables were written as the mean±SD, whereas categorical variables were documented as counts (percentages). The initial and final decimal visual acuity was converted into logarithm of the minimum angle of resolution (logMAR) values for statistical analysis. For VA of count fingers, hand motion and light perception, these measurements were converted to logMAR as described by Schulze-Bonsel et al.4
LogMar VA (preoperative and postoperative) between cumulative groups of onset of vision loss was compared with an independent t test. The differences in VA between the age groups or treatment techniques were tested either with an independent t test or with a non-parametric Mann–Whitney test depending on whether assumption of normality within each group was satisfied.
The p values from multiple comparisons were adjusted using Bonferroni correction. Statistical significance was set at 0.05 and analysis was performed using IBM SPSS Statistics V.20 (Armonk, New York, USA).
Results
Patient demographics
Records of 1727 patients operated by six surgeons were reviewed. Only 89 eyes (5.2%) from 89 patients met the inclusion and exclusion criteria. The mean age for the studied cohort was 61 years (range, 26–93 years). The mean duration between the onset of central visual acuity loss and surgical intervention was 11±7 days (range, 1–30 days). The mean length of FU was 185±28 days. A summary of patient demographics is shown in table 1.
Patient demographics
Visual outcome
The mean preoperative VA of 1.6 (range, 0.40 to 2.00) logMAR improved to 0.29 (range, 0.01 to 1.00) logMAR (p<0.001), with 65.2% (n=58) of all patients obtaining 0.7 logMAR (=0.2 decimal) or better FVA. The effect of central vision loss duration on FVA (at 6-month FU) is summarised in table 2.
Final visual acuity (FVA) of patients based on duration of vision loss before surgery of primary macula-off rhegmatogenous retinal detachment
Cumulative groups of patients with a shorter duration of symptoms and who had earlier surgical intervention achieved better FVA (table 2). According to our data there was no statistically significant difference (p=1.00, tested with independent t test and adjusted using Bonferroni correction, data not shown) in FVA of eyes with surgery within the first 3 days (n=33) after central vision loss. However, this message should be interpreted with caution as a low sample size and a relatively high SD in postoperative VA may not be statistically sufficient to discover differences between day 1 (n=10) versus day 2 (n=15) versus day 3 (n=8). After 10 days of central vision loss, although still statistically significant, no clinically relevant difference was seen in FVA as no difference of lines in VA could be obtained. On the other hand, eyes with loss of central vision of 3 days or less achieved clinically and statistically better FVA (p<0.001).
Further analysis was performed to determine whether age or the preoperative VA influenced visual outcome. Age (tested with Mann–Whitney test, data not shown) did not have any influence on FVA. The preoperative VA also did not influence FVA (p=0.17) although eyes with worse preoperative VA showed higher SD in FVA.
Surgical technique
There was no statistical significant difference in gender, eye laterality and choice of treatment options or treatment outcomes (data not shown). The lag time between onset of loss of central vision and surgical intervention was also similar among the groups (table 3). While PPV and PHV resulted in comparable FVA, eyes with SB showed statistically significant less appropriate FVA (p=0.012 and 0.007) although the preoperative mean VA was better in that group.
Effect of surgical technique on final vision after surgery of rhegmatogenous retinal detachment
Discussion
A major impact on the functional outcome of retinal detachment surgery is whether the macula is still attached or is part of the detachment.5 ,6 After a macula-off retinal detachment, improvement of central vision often remains compromised owing to the permanent functional damage the macula has suffered while detached. Photoreceptor apoptosis has been reported to mainly occur within 3 days of RRD onset in experimental animal models.7 ,8 Clinically, many cases of macula-off RRD undergo postoperative atrophy of the outer macular layer after reattachment. Even in cases where surgery has been successful, a reattached retina with macula-off rarely regains normal sensitivity or acuity.9
Several studies have concluded that the outcome of the surgical repair of macula-off retinal detachment is time dependent. After applying the above-mentioned strict inclusion and exclusion criteria, the medical records of 89 consecutive eyes with macula-off retinal detachment that underwent surgery with either PPV, PHV or SB from February 2010 to February 2015 at the Hamburg University Hospital were analysed. Our study suggested that surgery up to 3 days after central VA loss resulted in best FVA (mean FVA of 0.25±0.21 logMAR compared with 0.29±0.24 logMAR in eyes repaired within 10 days (p<0.001)). This is in line with van Bussel et al3 who showed FVA worsens already significantly after a maximal lag time of 3 days and deteriorates further with longer durations. According to our data, a pairwise comparison of eyes that had surgery at either day 1, 2 or 3 showed no statistically significant difference (p=1.00) in FVA. However, FVA steadily decreases from day 4 to day 10; after a lag time of at least 10 days, although statistically significant, no further clinically relevant difference was seen in FVA as no difference in lines of VA could be obtained (table 2). There was neither a significant correlation between the patients’ age, gender nor the preoperative VA and FVA. However, eyes with SB showed statistically significant less appropriate FVA (p=0.012 and 0.007) compared with PPV or combined surgery.
Several studies have explored the correlation between the duration of macular detachment and the final visual outcome following surgical repair. Hassan et al10 showed that better VA was achieved in eyes that were treated within 10 days after detachment. Burton11 found that there was a progressive decrease in VA beginning on the fifth day of macular detachment. Another study9 demonstrated that starting 6 days following the development of the retinal detachment, the visual outcome can be expected to become progressively worse. By contrast, Kim et al12 defined 7 days delay as cut-off after which visual outcome was not affected by further delay of treatment. Other studies7 ,8 ,13 noted no difference in anatomical or visual outcome in eyes repaired anytime within 7 days to 10 days of macular detachment. This is partly confirmed by Ross14 that showed the duration of macular detachment within the first week does not influence the visual recovery after surgery. Our results show that there was a steady decrease in VA up to 10 days after macular detachment. After 10 days of central vision loss, the final outcome was clinically comparable and independent of further delay of surgery up to 30 days. This could be explained by the patients’ selection in our study as we analysed eyes without further comorbidities which could additionally limit visual acuity during FU.
Nonetheless, we should admit that the outcome of any surgery also depends on the experience of the surgeon. Koch et al15 showed that the possibility to schedule surgery may improve delivery of care without compromising the outcome as they found a trend for better VA for experts and routine setting. In our study all surgeons were experienced and the cases were homogenously distributed among the surgeons involved.
The methods of treatment were SB and PPV or combined surgery. Recent studies16–20 suggested that primary PPV repair of RRD may result in different anatomical and visual outcomes compared with SB. According to those studies, accurate diagnosis of breaks and higher reattachment rate with a single surgery were allocated to PPV while phakic eyes benefit from SB with respect to VA improvement. Wolfensberger21 showed that foveal reattachment after macula-off RRD occurred faster after vitrectomy than after SB. However, the anatomical success rate is dependent on preoperative pathology; anatomical success rates after buckling surgery or PPV may be as high as 96%.22 While we cannot rule out any bias in patient selection completely, we consider it unlikely that so-called less severe cases have been treated with SB, while the more severe retinal detachments might have received PPV. Our data show that there was insignificant (p=1.00) difference in FVA between patients following PPV or PHV; surprisingly to the authors, SB, however, resulted in statistically significant less appropriate FVA (p=0.012 and 0.007). We hypothesised that advanced patient age, undocumented comorbidity rate, primary or secondary cataract or formation of epiretinal gliosis or preoperative VA could have negatively influenced these eyes. However, after testing each parameter, we could rule out any statistically significant impact on FVA. There was also no statistically significant difference in outcome between men and women, eye side or surgeon (data not shown). In our clinical experience, however, SB offers a good and safe surgical option and is preferably used in cases with 1–2 quadrants (3–6 h) RRD where the macula is not involved. The negative trend in the current analysis could be explained by the lack of preoperative optical coherence tomography data, because the height of macular detachment seems to play a major role in the functional outcome (of buckling surgery) in cases of macula-off. It is known that a lower height of macular detachment correlates with better visual recovery.14 Moreover, functional findings from standard automated perimetry or focal electroretinography could also be advantageous when discussing retinal integrity after detachment. In all cases, macular involvement was diagnosed by preoperative and intraoperative funduscopy; nevertheless as mentioned above, this study does not deliver exact data on the extent of the detachment. Another limitation is that the report on symptoms duration is rather subjective and may vary between individuals.
On the other hand, advantages of our study are the application of strict inclusion and exclusion criteria (only 89 (=5.2%) from 1727 were included) and thus, we were able to focus on the distinct role of onset of central VA acuity loss and its impact on final visual outcome.
To conclude, our study suggests that:
After 10 days of central VA loss, the final visual outcome is clinically comparable and independent of further delay of surgery up to 30 days.
Eyes treated up to 3 days after onset of loss of central vision have better FVA than eyes with longer lag time. However, we did not find statistically significant differences within the first 3 days.
Surgery for macula-off retinal detachment may therefore most likely not be postponed without compromising the patient's visual prognosis.
We currently set out to investigate the distinct role of ocular (ie, glaucoma) and systemic pathologies (ie, diabetes) in FVA in a separate study.
Acknowledgments
The authors would like to thank Mrs Verena Frings who took time from her busy schedule to read the manuscript when it was in need of a critical reappraisal.
References
Footnotes
Contributors AF and LW: conception and design, analysis and interpretation of data. AF, NM, TK, BS, CS, VD and LW: drafting the article or revising it critically for important intellectual content. LW: final approval of the version to be published.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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