To use spectral-domain optical coherence tomography (SD OCT) to evaluate macular hole surgery outcomes and features predicting anatomic failure.
Retrospective, interventional case series.
Fifty-two eyes of 50 consecutive patients with macular holes were examined. All eyes underwent 3-port pars plana vitrectomy with internal limiting membrane peeling. Eyes were examined after surgery by dense serial SD OCT scanning over the macula.
Eyes with initial anatomic failure were significantly more likely to have greater axial length and refractive error and more posterior staphyloma compared with eyes with initial anatomic success ( P = .031 to .0060, < .0001). Overall initial and final anatomic success rates were 92.3% (48 of 52 eyes). In highly myopic eyes with axial lengths of 26.0 mm or more, initial and final success rates were 73.3% (11 of 15 eyes) compared with 100.0% (37 of 37 eyes) of eyes with axial lengths of less than 26.0 mm ( P = .0050). In highly myopic eyes, initial and final success rates were 0% (0 of 3 eyes) of eyes with axial lengths of 30.0 mm or more compared with 91.7% (11 of 12 eyes) of eyes with axial lengths of 26.0 mm or more and of less than 30.0 mm ( P < .0001). Retinoschisis-like thickening of the outer retina was seen in 3 (75.0%) of 4 eyes with initial failure compared with 3 (6.3%) of 48 eyes with initial success ( P = .0030).
Axial length of 30.0 mm or more may increase the risk of anatomic failure of macular hole surgery.
Based on the theory that vitreous traction is the cause of idiopathic macular holes, vitreoretinal surgery to relieve traction has become the established treatment and currently is highly successful for closing macular holes. In a pilot study reported in 1991, Kelly and Wendel achieved a 58% success rate for anatomic closure of full-thickness macular holes using pars plana vitrectomy (PPV) with posterior hyaloid peeling and intraocular gas tamponade. For surgery in which internal limiting membrane (ILM) peeling was also performed, primary closure rates of 76.4% to 100% have been reported.
Shorter duration of symptoms, earlier stage or smaller size of the macular hole, better preoperative visual acuity, younger patient age, and male gender have been reported to be associated significantly with better surgical outcomes. However, consensus is lacking that high myopia and longer axial length is related to worse outcomes of macular hole surgery. Patel and associates reported a relatively low (60%) closure rate for macular holes in highly myopic eyes. However, in case-control studies, Sulkes and associates and Kobayashi and associates found no association between axial length and anatomic success of surgery. However, these studies did not use optical coherence tomography (OCT) to confirm closure of the macular hole, and it can be difficult to determine whether macular holes are closed by biomicroscopic examinations alone, especially in highly myopic eyes with choroidal atrophy, as shown by Coppé and associates, who detected macular holes by OCT in 24 (6.26%) of 383 asymptomatic myopic eyes.
With more recently developed spectral-domain (SD) OCT technology, macular features can be visualized in great detail. Commercially available SD OCT instruments acquire images 43 to 133 times faster than time-domain (Stratus; Carl Zeiss Meditec, Dublin, California, USA) OCT instruments, which allows for acquisition of densely spaced serial B-scans that can be used to detect macular holes more precisely. High-speed image acquisition also allows averaging of multiple OCT B-scans at each location of interest on the retina, so as to reduce speckle noise and thus provide a detailed view of macular anatomic features. In this study, we used SD OCT to study the relationship between preoperative and postoperative factors and the success of macular hole surgery.
Patient data were obtained by retrospective review of the medical records of 49 consecutive patients (52 eyes) who underwent surgery for macular hole at Kyoto University Hospital between February 2006 and July 2008. Candidates for the study were identified by review of the authors’ surgical lists for the study period. The inclusion criteria for this study were as follows: (1) clinical presentation of macular hole, (2) treatment with conventional 20-gauge or 23-gauge 3-port PPV with ILM peeling, and (3) a follow-up period of more than 6 months from the last intraocular surgery. Eyes were excluded from the study if they had pre-existing ocular diseases or a history of ocular surgery, except for cataract surgery. Other exclusion criteria included (1) a history of treatment for peripheral retinal breaks before and after the primary surgery or (2) macular hole with retinal detachment.
All patients had undergone comprehensive ophthalmologic examinations before macular hole surgery, measurements of refractive errors (ARK-700A autorefractor; Nidek, Gamagori, Japan), measurements of uncorrected visual acuity and best-corrected visual acuity (BCVA) using the 5-m Landolt chart, measurement of axial length using A-scan ultrasonography (UD-6000; Tomey Corp., Nagoya, Japan), slit-lamp examinations, measurements of intraocular pressure using a Goldmann applanation tonometer, and dilated indirect slit-lamp biomicroscopy. The size of each macular hole before surgery was measured with reference to the diameter (approximately 150 μm) of the vein on the edge of the optic disc.
Conventional 20-gauge 3-port PPV was performed in 10 eyes and 23-gauge transconjunctival PPV was performed in the other 43 eyes. A posterior vitreous detachment was created, followed by removal of the residual thin premacular posterior cortex. The peripheral vitreous also was excised. Triamcinolone acetonide was used during surgery to facilitate visualization of the vitreous and posterior hyaloid in all of the eyes in this study. All of the eyes underwent ILM peeling (3 to 4 disc diameters in size) with an ILM forceps, after staining with indocyanine green or triamcinolone acetonide. In all eyes, fluid–air exchange was performed, followed by gas tamponade (instillation of 40 mL sulfur hexafluoride, 25%). Patients were instructed to keep the head prone (face downward) for at least 1 week after surgery. In the 46 of 52 eyes (88.5%) that were phakic before macular hole surgery, phacoemulsification was performed before PPV, with implantation of an intraocular lens in all 46 eyes.
Optical Coherence Tomography Examinations
OCT examinations were performed by experienced ophthalmologists using time-domain OCT (Stratus), SD OCT (usually Spectralis HRA+OCT [Heidelberg Engineering, Heidelberg, Germany] or occasionally RTVue-100 [Optovue, Fremont, California, USA]). On preoperative scans of eyes with moderate cataract, time-domain (Stratus) OCT images tended to provide better information than SD OCT scans.
SD OCT was used only after surgery. To determine whether the macular hole closed after surgery, dense serial SD OCT scans were obtained over the macula; scanning usually was horizontal, but sometimes was vertical or radial. Initial anatomic success was defined as no visible open macular hole on any serial SD OCT B-scans during the first month after the first macular hole surgery. To identify possible abnormalities in retinal microanatomic features, so-called speckle-noise–reduced images were generated by averaging 20 to 50 SD OCT B-scans obtained at each location of interest on the retina.
Statistical analyses were performed using SPSS software version 17.0 (SPSS, Inc, Chicago, Illinois, USA). The logarithm of the minimal angle of resolution (logMAR) was used for statistical analyses involving visual acuity. For continuous values, the mean ± standard deviation was calculated for each group, and differences between 2 groups and 3 groups were evaluated for statistical significance by the Mann–Whitney U test and the Kruskal-Wallis H test, followed by the Dunnett rank test, respectively. Differences in categorical variables were evaluated for statistical significance by the Fisher exact test.
Fifty-two eyes of 49 patients (18 men, 31 women) with macular holes were included in this study. The 49 patients had a mean age ± standard deviation of 63.4 ± 8.6 years (range, 34 to 82 years) and the 52 eyes had a mean ± standard deviation preoperative refractive error of −3.0 ± 5.2 diopters (range, 4.4 to −18.5 diopters). The median preoperative BCVA (Snellen equivalent) for the 52 eyes was 20/80 (range, 20/500 to 20/25).
Factors Associated with Initial Failure of Macular Hole Surgery
Table 1 shows the preoperative and postoperative characteristics of eyes in which the initial surgery was a success or failure. There were significant preoperative differences between the groups in mean axial length ( P < .0001), refractive error ( P = .031), and whether there was posterior staphyloma ( P = .0060).
|Factor||Initial Success||Initial Failure||P Value||All Eyes|
|No. of eyes||48||4||52|
|Mean patient age ± SD (range; n = 50), yrs||63.4 ± 8.9 (34 to 82)||63.0 ± 5.0 (58 to 70)||.70 a||63.4 (34 to 82)|
|No. of men/women||20/28||0/4||.15 b||20/32|
|No. of right eyes/left eyes||25/23||3/1||.62 b||28/24|
|Mean axial length ± SD (range), mm||24.2 ± 1.87 (21.1 to 28.1)||30.0 ± 2.3 (26.7 to 31.9)||<.0001 a||24.6 (21.1 to 31.9)|
|Mean preoperative refractive error ± SD (range), diopters||−2.36 ± 4.41 (4.4 to −14.4)||−10.3 ± 8.89 (−2.5 to −18.5)||.031 a||−3.0 ± 5.2 (−18.5 to 4.4)|
|Macular hole stage|
|Mean symptom duration ± SD (range), mos||3.1 ± 2.6 (0.5 to 12)||10.0 ± 12.3 (1 to 24)||.39 a||3.5 ± 4.0 (0.5 to 24)|
|Size of hole, relative to disc vein diameter||4.0 ± 1.6 (1.2 to 9.7)||5.8 ± 1.4 (4.7 to 7.4)||.056 a||4.1 ± 1.6 (1.2 to 9.7)|
|Mean preoperative logMAR BCVA ± SD (range)||0.60 ± 0.33 (0.046 to 1.40)||0.89 ± 0.36 (0.398 to 1.222)||.11 a||0.62 ± 0.34 (0.050 to 1.40)|
|Mean postoperative logMAR BCVA ± SD (range) c||0.247 ± 0.32 (−0.18 to 1.05)||0.87 ± 0.42 (0.40 to 1.40)||.0050 a||0.30 ± 0.36 (−0.18 to 1.40)|
|Preoperative OCT findings|
|Posterior staphyloma||4||3||.0060 b||7|
|Retinoschisis-like thickening||3||3||.0030 b||6|
Grouping According to Axial Length
Mean axial length for the 52 eyes (24.6 ± 2.4 mm; range, 21.1 to 31.9 mm) was correlated negatively with age ( r = −0.447; P = .001; Figure 1 ), but positively correlated with refractive error ( r = −0.715; P = .0001). Three (60%) of 5 eyes with initial surgical failure were outliers on the linear regression curve ( Figure 1 ). All 3 eyes had axial lengths of 30.0 mm or more. Accordingly, the 52 eyes were divided into 3 groups based on whether they had severely high myopia (group 1), defined as an axial length of 30.0 mm or more; moderately high myopia, defined as an axial length of 26.0 mm or more and less than 30.0 mm (group 2); or mild myopia, emmetropia, or hyperopia (group 3), defined as an axial length of less than 26.0 mm ( Table 2 ). Eyes were statistically significantly different among the 3 groups in mean age at onset of macular holes, mean axial length, and mean preoperative refractive error and in terms of the existence of posterior staphyloma (all P < .0001), but not significantly different in patient gender, laterality, stage or size of macular hole, duration of symptoms, or preoperative logarithm of the minimal angle of resolution BCVA ( Table 2 ).
|High Myopia||Emmetropia/Mild Myopia/Hyperopia (G3)||P Value a||Total (G1 + G2 + G3)|
|Severely High Myopia (G1)||Moderately High Myopia (G2)||All (G1 + G2)||Among 3 Groups||G1 vs G2||G1 vs G3||G2 vs G3|
|Axial length (mm)||≥26.0||≥26.0||<26.0|
|No. of patients||3||10||13||36||49|
|Mean patient age ± 1 SD (range), yrs||63.3 ± 6.1 (58 to 70)||54.2 ± 9.4 (34 to 70)||56.0 ± 9.4 (34 to 70)||66.4 ± 6.2 (56 to 82)||<.0001 b||.232 c||.800 c||.002 c||63.4 ± 8.60 (34 to 82)|
|No. of men/women||0/3||3/7||3/10||15/21||.40 d||18/31|
|No. of eyes||3||12||15||37||52|
|No. right eyes/left eyes||2/1||6/6||8/7||20/17||1 d||28/24|
|Macular hole stage|
|Symptom duration (range), mos||10.0 ± 12.3 (1 to 24)||3.3 ± 2.2 (0.75 to 6)||4.8 ± 6.1 (1 to 24)||3.0 ± 2.8 (0.5 to 12)||.60 b||3.5 ± 4.0 (0.5 to 24)|
|Mean axial length ± SD (range), mm||31.0 ± 0.9 (30.1 to 31.9)||27.0 ± 0.7 (26.0 to 28.1)||27.8 ± 1.8 (26.0 to 31.9)||23.4 ± 1.1 (21.1 to 25.7)||<.0001 b||.019 c||<.005 c||<.0001 c||24.6 ± 2.4 (21.1 to 31.9)|
|Refractive power, diopters||−7.9 ± 9.2 (−18.5 to −2.5)||−9.6 ± 3.9 (−17.4 to −3.8)||−9.3 ± 5.0 (−18.5 to −2.5)||−0.4 ± 2.3 (−5.5 to 4.4)||<.0001 b||.99 c||.54 c||<.0001 c||−3.0 ± 5.2 (−18.5 to 4.4)|
|Size of hole relative to disc vein diameter||5.8 ± 1.4 (4.7 to 7.4)||4.6 ± 2.7 (1.5 to 9.7)||4.9 ± 2.4 (1.5 to 9.7)||3.9 ± 1.3 (1.2 to 6.7)||.14 b||4.1 ± 1.6 (1.2 to 9.7)|
|Mean logMAR BCVA ± SD (range)||0.77 ± 0.35 (0.40 to 1.10)||0.70 ± 0.44 (0.10 to 1.40)||0.71 ± 0.42 (0.10 to 1.40)||0.59 ± 0.30 (0.05 to 1.05)||.54 b||0.62 ± 0.34 (0.05 to 1.40)|
|Posterior staphyloma||3||3||6||1||<.0001 d||.070 d||.0004 d||.028 d||7|
|Retinoschisis-like thickening present||2||2||4||2||.01 d||.15 d||.02 d||.25 d||6|
|Hole closure, no. (%)|
|Initial||0 (0)||11 (91.7)||11 (73.3)||37 (100)||<.0001 d||<.0001 d||<.0001 d||.24 d||48 (92.3)|
|Final||0 (0)||11 (91.7)||11 (73.3)||37 (100)||<.0001 d||<.0001 d||<.0001 d||.24 d||48 (92.3)|
|Mean logMAR BCVA ± SD (range) e||0.93 ± 0.50 (0.40 to 1.40)||0.33 ± 0.31 (0.05 to 1.00)||0.45 ± 0.30 (0.05 to 1.40)||0.23 ± 0.32 (−0.18 to 1.05)||.042 b||.34 c||.27 c||.75 c||0.30 ± 0.36 (−0.18 to 1.40)|
|Mean change in logMAR BCVA ± SD (range)||0.16 ± 0.15 (0 to 0.3)||−0.39 ± 0.42 (−1.24 to 0)||−0.26 ± 0.43 (−1.24 to 0.30)||−0.36 ± 0.32 (−1.0 to 0.22)||.036 b||.015 c||.020 c||1.00 c||−0.33 ± 0.36 (−1.24 to 0.30)|
Anatomic and Functional Success According to Axial Length
The overall initial and final anatomic success rates of the macular hole surgeries were both 92.3% (48 of 52 eyes; Table 2 ). The median final BCVA (Snellen equivalent) was 20/32 (range, 20/500 to 20/12.5). In eyes with axial lengths of less than 26.0 mm, the initial and final success rates were both 100.0% (37 of 37 eyes), and in highly myopic eyes with axial lengths of 26.0 mm or more, the initial and final success rates were both 73.3% (11 of 15 eyes); this difference was significantly different (both P = .0050). In highly myopic eyes with axial lengths of 30.0 mm or more, the initial and overall success rates were both 0% (0 of 3 eyes), whereas in highly myopic eyes with axial lengths of 26.0 mm or more and less than 30.0 mm, the initial and final success rates were both 91.7% (11 of 12 eyes). The initial and final success rates in eyes with axial lengths of 30.0 mm or more were significantly lower than those in eyes with axial lengths 26.0 mm or more and less than 30.0 mm and in eyes with axial lengths of less than 26.0 mm ( P < .0001 for both; Table 2 ). At 6 months after the last surgery, the mean change in logarithm of the minimal angle of resolution BCVA in eyes with axial lengths of 30.0 mm or more also was significantly smaller than those in eyes with axial lengths of 26.0 mm or more and less than 30.0 mm ( P = .015) and in eyes with axial lengths less than 26.0 mm ( P = .020; Table 2 ).
Spectral-Domain Optical Coherence Tomography Findings
On SD OCT images obtained before surgery, almost all eyes with all stages of macular holes (2, 3, or 4) had centrifugal elevation of the retina limited to the fovea and cystoid spaces in the Henle nerve fiber layer and sometimes in the inner nuclear layer, in the fovea, or just outside the fovea ( Figure 2 ).
However, on preoperative SD OCT images of 6 (11.5%) of the 52 eyes, a retinoschisis-like feature was seen consisting of widespread thickening of the retina in the extrafoveal as well as the foveal region ( Figures 3 and 4 ). The thickening appeared to be located in the outer retina. The retinoschisis-like feature was seen in 3 (6.3%) of 48 eyes with initial success and in 3 (75.0%) of 4 eyes with initial failure of macular hole surgery; this difference was statistically significant ( Table 1 ; P = .0030). This retinoschisis-like feature was found to be associated with axial lengths ( Table 2 ). In eyes with axial lengths of 26.0 mm or more, the retinoschisis-like feature was seen in 3 (75%) of the 4 eyes with initial failure, compared with only 1 (9.1%) of 11 eyes with initial success ( Table 3 ); this difference was statistically different ( P = .033).