Anatomical and Visual Outcome following Macular Hole Surgery at a Tertiary Eye Care Centre in Nepal

Introduction: Macular hole (MH) leading to central vision loss is common in the elderly. This study aimed to explore the anatomical and functional outcome of MH surgery at a tertiary eye care setting in Nepal. Methods: This retrospective, interventional case series study included patients who had undergone MH treatment with pars plana vitrectomy, membrane peeling and perfl uoropropane gas (C3F8) from 2007 January to 2010 August and had completed three months of follow up. The best corrected visual acuity (BCVA) and anatomical status of MH assessed with bio-microscopy and optical coherence tomography (OCT) at six weeks, three months and at the last follow-up following surgery were recorded. Results: A total of 36 cases with the age range of 11 73 years and the mean age of 53.2 years (19.3 S.D) were included in the study. The mean duration of decreased vision was 11.1 months (12.1 S.D). Idiopathic macular hole comprised of 31 cases (86.1 %) and traumatic of fi ve cases (13.9 %). The mean follow-up period was 9.4 months. The MH closed in 27 cases (75 %) at six weeks and in 28 cases (77.8%) at three months and at the last follow-up. The vision had improved in 36 % of cases, with more than 2 lines in 27.8 %, and was stable in 27.7 % of cases during the the last follow-up. The anatomical success rate was higher in the idiopathic MH (80.65 %) than in the traumatic (60 %) and visual acuity improved in 45 % of cases in the idiopathic and 20 % in the traumatic cases. Conclusions: The overall anatomic success rate was 78 % and improvement in visual acuity was seen in one -third of cases. The success rate was higher among idiopathic MH than in traumatic. ________________________________________________________________________________________


INTRODUCTION
Macular hole is a posterior segment problem of the eye leading to central vision loss.Idiopathic macular hole occurs primarily in the elderly, with female predominance after the sixth decade of life although macular holes due to secondary causes like trauma and high myopia are seen in young adults. 1 Macular hole is usually diagnosed late as patients are unaware of this problem due to its characteristics feature of gradual painless diminution of vision.More than a century following the fi rst description of macular hole by Henry Noyes in 1871, 2 Kelly and Wendell fi rst reported the successful closure of macular holes by pars plana vitrectomy and membrane peeling in 1991, with the anatomical success rate of 58 %. 3 Subsequent series have been reported since then, with higher anatomic and functional success using various surgical techniques in selected cases. 1,4,5 atomical and physiological success largely depends on the size and duration of MH 6,7 but late presentation, costly surgical set-up for pars plana vitrectomy and lack of trained man power further complicate the timely treatment of MH in developing nations like Nepal.
To the best of our knowledge, there are no published case series regarding the outcome of macular hole surgery in Nepal.We hope this study will be useful to explore the anatomical and visual outcome following macular hole surgery at our hospital set up.

METHODS
This is a retrospective, interventional case series study conducted at the Tilganga Institute of Ophthalmology (TIO), a tertiary eye care centre of Nepal, from January 2007 to August 2010.Ethical approval was obtained from the Ethical Committee of the Institutional Review Board.Inclusion criteria included stage 2 to stage 4 idiopathic and traumatic MHs treated with pars plana vitrectomy, membrane peeling and perfl uoropropane gas (C3F8) and followed by a follow-up duration of at least three months.Macular hole associated with other macular pathology limiting visual acuity, like nonproliferative or proliferative diabetic retinopathy, agerelated macular degeneration, high myopia, previous retinal detachment surgery or concomitant retinal detachment, and cases with vitritis, posterior uveitis, retinal vein occlusion and those with a follow-up period of less than three months following surgery were excluded from the study.The staging of MH was determined bio-microscopically with a slit-lamp examination according to Gass Classifi cation and by optical coherence tomography (OCT). 8The maximum linear dimension (MLD) as defi ned by the greatest linear distance along the smallest hole aperture was recorded. 6The pre-operative data included were age, sex, duration of visual symptoms, laterality, ocular trauma prior to visual problem, best-corrected visual acuity (BCVA), and the MLD of macular hole.The intraoperative data recorded were type of vitrectomy (20 G and 23/25 G vitrectomy), presence or absence of ERM, use of intravitreal triamsinolone, indocyanine green, ILM peeling and any other intra-operative complications.Intravitreal triamsinolone was used in all cases for the visibility of complete posterior vitreous detachment (PVD).If no PVD was present, the elevation of the posterior hyaloids was induced via suction of the vitrectome.An epiretinal membrane (ERM) was removed if present.Indocyanine green, 0.5 %, 0.2 ml, was injected intravitreal in fi ve cases and a peeling of the inner limiting membrane (ILM) was performed with intraocular end-gripping forceps in all cases.Fluid -air exchange was followed by fl ushing with 50 ml of C3F8 16 % gas prior to closure of sclerotomies.
Patients with concurrent visually signifi cant cataract underwent phacoemulsifi cation with intra-ocular lens implantation at the same setting.The intra-operative period was uneventful in all cases.After surgery, oral acetazolamide 250 mg was prescribed three times a day for three days and oral analgesics as and when necessary.Patients were advised to maintain a facedown positioning for at least seven days.Patients were prescribed topical medications containing an antibiotic and steroid combination (chloramphenicol and dexamethasone) every two hourly, cycloplegics (Tropicamide) at bed time for a week and antiglaucoma medications in cases with raised intraocular pressure.Topical medications were reduced in a tapering dose and stopped at the end of six weeks.The post-operative data included were BCVA using Snellen chart, grading of cataract in phakics, clinical and OCT evaluation of macular hole and intraocular pressure (IOP) at six weeks, three months and at the last follow-up.
Postoperative anatomical success was defi ned as fl attening of the macular hole with no sub-retinal fl uid.Visual acuity was then converted to a logarithm of the minimum angle resolution algorithm to convert into a line score to record the number of lines gained or lost after surgery.Data was tabulated and analyzed using SPSS 11 (SPSS Inc; Chicago, IL, USA).The Spearman's rank correlation coeffi cient was used to assess the correlation of age with anatomic success.

RESULTS
A total of 36 patients (36 eyes) with the age ranging from 11 -73 years and the mean age of 53.2 years (19.3S.D) were included in the study.Females slightly outnumbered males, comprising of 19 cases (58.3 %) and 17 cases (41.7 %) respectively.Nearly half of the patients were in the age range of 60 -75 years (Table 1).poor vision of more than a year (Table 2).The last follow-up period ranged from 3 -36 months with the mean follow-up of 9.4 months (8 S.D).Onethird of the cases followed up for three months and nearly one-fi fth followed up for more than a year (Table 4).The macular hole was closed (anatomical success rate) in 27 cases (75 %) at the six-weeks follow-up.Likewise, the macular hole was closed in 28 cases (77.8 %) at follow up visits of 3 months and at the last follow-up (Table 5).All patients with post-operative complications like transient rise in IOP and retinal detachment had anatomical success.The vision improved with more than two lines following retinal detachment surgery whereas in cases with high IOP, the vision at the last follow-up was worse than the pre-operative visual acuity.During the subsequent follow-ups, the two cases had transient rise in intra-ocular pressure and one case was diagnosed as primary angle closure glaucoma and these were managed successfully with anti-glaucoma medications.One case had retinal detachment at one month followup and was managed with scleral buckle, pars plana vitrectomy, endolaser and silicon oil temponade.(68 years; age range 50 -80 years).This disparity in the ageing pattern could be due to the lower life expectancy and the inclusion of cases with traumatic macular hole of the younger age patients in our series.The female predominance for macular hole in our series was similar to those in other series. 1,7,10,11he mean duration of decreased vision in our series (11 months) was longer than that mentioned in other studies. 1,10This might be due to the tendency of late presentation for ocular consultation of our cases.The reason for delayed consultation could be due to the lack of awareness of the seriousness of the problem, lack of trained manpower for vitrectomy surgery and due to poor transportation facilities from the remote areas of the country.The idiopathic MH seen in the maximum number of cases in our series may be because of the commonest etiology seen worldwide, including in Nepal.
Although not a common problem, young patients also presented to our hospital set-up with a macular hole of traumatic origin.
.The overall anatomical closure rate in our series was 78 %, with 80.6 % in the idiopathic group and 60 % in the traumatic group during the last follow-up.Our anatomical success rate in idiopathic cases were nearly similar to the series by Gupta et al. 6 (86 %) but was Thapa et.al. Outcome of macular hole surgery lower than in the series by Posselt et al. 10 , (96 %), Muesseler et al. 12 (100 % and 96 %), and Kwok et al. 13 (92.3%).The better results in their series could be due to the ICG assisted complete peeling of ILM which is thought to yield a better anatomical success rate. 10,13,14n our series, there was a correlation between age and the anatomical success of macular hole but it was not statistically signifi cant (Spearman's rank correlation coeffi cient, r=0.63, p=0.37).Less anatomical success in the early age groups could be due to the predominant traumatic MH and the higher success in the elderly group having idiopathic MH.Again, the relatively lower anatomical success among the age group >70 years may be due to the longstanding chronic MH.
The overall visual success (6/18 and better snellen acuity) in our series was 11 %, unlike in the series by Gupta et al. (33 %). 6The better results in their series could be due to the concurrent phacoemulsifi cation with intraocular lens implantation among all phakic patients.The relatively lower visual outcome in our series could be due to the varying grades of cataract where only 16.7 % of the cases had undergone cataract surgery till the study period and inclusion of traumatic macular hole that are usually associated with retinal pigment epithelial change and macular scar limiting good visual recovery.
Among the cases with the macular hole of < 400 micron, the anatomical success and visual improvement of more than two lines was achieved in 100 % in our study, unlike in the series of Gupta et al. 6 with anatomical success of 93 % and visual success of 42 % among the cases with the macular hole of < 400 micron.But the sample size of our series was quite small.Likewise, among the cases with the macular hole of > 400 micron, the anatomical success was 77 % and visual success 20 % in the series of Gupta et al. 6 Our results were nearly similar to their fi ndings, with the anatomic success of 68 % and visual improvement in 26.3 %.Likewise, in the series of Posselt et al. 10  But there was no signifi cant change in visual outcome among the different surgical procedures.Some studies had concluded that though the anatomic success is better with ICG, the relatively poor visual outcome may be due to the toxic effects of ICG. 5 15,16 In our series, ILM peeling without the use of any ILM staining agents like ICG was done in the majority of cases (86 %) but the anatomical success and visual outcome were not different among the two groups.
Although the sample size of the ICG users was very small because routine ICG use is not possible, in developing nations like Nepal results were encouraging due to its high cost.
We were unable to correlate the anatomical and visual success rate among cases with pre-existing PVD and surgically-induced PVD cases due to lack of adequate information in the medical records in this retrospective case series.

CONCLUSIONS
Despite the relatively long duration of macular hole and various grades of cataract in our series, the overall anatomic success rate was 78 % and improvement in visual acuity was present in one-third of cases (36 %) during the last follow-up.The success rate was higher among the idiopathic than in the traumatic macular hole and with a smaller macular hole size.The concurrent Thapa et.al. Outcome of macular hole surgery phacoemulsifi cation and intraocular lens implantation along with the use of ICG might help to increase our overall anatomical and visual success in selective cases in the future.

Table 1 .
Age and gender distribution of patients.
The mean duration of decreased vision was 11.1 months (12.1 S.D).Nearly three-fi fths (58.77 %) of the patients had a history of decreased vision of within six months whereas one-fi fth (22.2 %) had a history of Thapa et.al. Outcome of macular hole surgery

Table 8 .
Correlation of age with anatomic success of the macular hole surgery at the last follow-up 10n our series, despite the longer duration of macular hole and varying grades of cataract at the last follow-up, the overall success rate was 78 % with improvement in visual acuity in one-third of cases.The mean age of patients in our series was 53.2 years, which was lower as compared to that of the series by Posselt et al.10(71 years; age range 62 -78 years), HirneiB et al. 11 (67 years; age range 50 -78 years), Schurmans et al. 1 ( 69 years; age range 51 -82 years); Ullrich et al.
5f improvement in vision of two lines in phakic, compared with 4.2 lines in the group that underwent cataract surgery concurrently or at the time of silicon oil removal.Ando et al.5have reported the improved anatomic success following ILM peeling with ICG (100%) as compared with ILM peeling without ICG (85.7 %) and with simple PPV with complete PVD and FAE with face down positioning for a week (85.4%).