Clinical and Experimental Ophthalmology (2002) 30, 261–265

Original Article _____________________________________

Original Article

Vitreous surgery in highly myopic retinal detachment resulting from a macular holeLin Lu MD, Yonghao Li MD, Shengshi Cai MD and Jiu Yang MDEye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou, China

ABSTRACT

Purpose: This study aimed to assess the therapeutic effectof vitreous surgery in conjunction with photocoagulationfor highly myopic retinal detachment resulting from amacular hole.

Methods: Sixty-two consecutive highly myopic patients(65 eyes) with retinal detachment from macular holesunderwent vitreous surgery. Gas tamponade in conjunctionwith laser photocoagulation was performed in 46 eyes (44cases, group 1); gas tamponade only was performed in 12eyes (11 cases, group 2); and silicone oil tamponade onlywas performed in seven eyes (seven cases, group 3).Additional laser photocoagulation was given in group 1 ifnecessary. The anatomical and functional success rateswere compared between the groups.

Results: Primary retinal reattachment was achieved in 43eyes (93.5%) in group 1, seven eyes (58.3%) in group 2 andfour eyes (57.1%) in group 3. Final visual acuity was 6/60 ormore in 24 eyes (52.2%) in group 1, in six eyes (50.0%) ingroup 2 and in three eyes (42.9%) in group 3. The initialretinal reattachment rate was significantly higher in group 1than in group 2 (P = 0.0075) and group 3 (P = 0.0248).The macular hole was completely closed in 18 eyes ingroup 1 and one eye in group 2 after 2 months or longer.A thin fibrous membrane and scar could be easily noticedbeneath the macula in 15 eyes.

Conclusion: Vitreous surgery in conjunction with laserphotocoagulation can improve the surgical success rate forhighly myopic retinal detachment resulting from a macularhole.

Key words: macular hole, myopia, photocoagulation, retinaldetachment, surgery.

BACKGROUND

In highly myopic eyes with macular holes and retinaldetachment, laser photocoagulation to the hole marginduring vitrectomy and fluid gas exchange improves thesurgical success rate for retinal detachment.

Reduced retinal adherence to the choroid and increasedtangential traction are believed to be the causes of retinaldetachment from macular hole.1–3 The presence of posteriorstaphyloma and atrophy of the retinal pigment epithelium(RPE) causes reduced retinal adherence to the choroid. Theinternal limiting membrane (ILM) may increase the retinaltraction.4

In response to these considerations, some surgeons havesuggested removing the ILM to release the traction. How-ever, the ILM is thin, friable and firmly adherent to theretina in high myopia. Therefore, it is difficult to remove itfrom the retina completely.3,4 Oshima et al. designed adiamond-dusted brush to separate the ILM.5 Further histo-logical study of any possible mechanical damage induced byscraping the neural retina is pending. The role of membranepeeling also remains controversial.6

In order to increase the retinal adherence, some adjuvantgrowth factors were applied to facilitate foveal wound heal-ing.7–9 Some investigators have advocated silicone oil tam-ponade,10 or laser photocoagulation,11–13 for the treatmentof macular holes. However, it is uncertain whether laserphotocoagulation improves the success rate of the operationin highly myopic retinal detachment resulting from amacular hole.

We investigated the therapeutic effect and complicationsof vitreous surgery with macular hole margin laser photo-coagulation during retinal detachment surgery in patientswith high myopia and a macular hole.

METHODS

This retrospective study was carried out with 62 consecutivepatients (65 eyes) who had high myopia with retinal detach-ment caused by macular hole. All the patients underwent

� Correspondence: Dr Lin Lu, Eye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, 54 Xianlie Road, Guangzhou, 510060,

China. Email: lulin888@public.guangzhou.gd.cn

262 Lu et al.

surgical management in our centre between January 1994and December 1999. The patient selection criteria were:(i) a refractive error of –6.00 D or more; (ii) an axial globelength, measured by A-scan echography, of 26 mm or more;and (iii) a diagnosis of retinal detachment due to a macularhole having been established clinically by a detailed ocularexamination that included indirect ophthalmoscopy and/ora contact three-mirror lens examination.

The patients were recruited into three groups dependingon operation type. From January 1994 to March 1995, 11cases (12 eyes) were treated with long-acting gas tamponadeonly (group 2). From April 1995 to December 1999, 44cases (46 eyes) were treated with long-acting gas tamponadein conjunction with macular hole margin laser photocoagu-lation (group 1) and the other seven cases (seven eyes) weretreated with silicone oil tamponade only (group 3).

The preoperative data recorded were: age, sex, eye affected,duration of disease, corrected Snellen visual acuity, lens status,presence of posterior vitreous detachment (PVD), extent of theretinal detachment, refraction and axial globe length.

Postoperative data included the anatomical result, bestcorrected visual acuity and complications. From January1994 to December 1998, we used contact lens biomicro-scopy, fundus fluorescein angiography (FFA) and, later,optical coherence tomography (OCT) to confirm whetherthe edges of the macular hole had been attached to thechoroid in group 1 within 2–8 weeks after the operation. Allpatients were followed up for 6 months or more (average27.6 months).

A standardized pars plana vitrectomy was performed inall eyes. Fragmatome lensectomy was performed in two eyeswith cataract obscuring fundus visibility. If a PVD was notpresent, the vitreous cortex was separated from the opticdisc using cutter suction or a silicone-tipped cannula with

active suction. A complete vitrectomy with removal ofperipheral vitreous was intended. The absence of the fish-strike sign with a silicone-tipped cannula helped confirm theremoval of posterior vitreous cortex. We removed the ILMfrom the detached retina around the macular hole only if itwas visible and could be easily removed. Afterwards anair–fluid exchange was performed.

In group 1, the macular hole margin endolaser photo-coagulation was of 0.2 s duration and 100–400 mW powerin a circular pattern just on the edge of the macular hole.Tamponade with long-lasting gas was performed and theintraocular pressure assessed.

In group 2, patients received long-lasting gas tamponadeafter vitrectomy without laser, while group 3 patients under-went silicone–air exchange after air–fluid exchange.

Various gases were used according to the time of retinaldetachment and the rigidity of the retina: 10% of C3F8 wasused as a long-term tamponade; 12–14% of C2F6 was used asa medium-term tamponade; and 16–20% of SF6 was used asa short-term tamponade.

Patients maintained a prone position for 16 h daily for atleast 14 days after the operation. Contact lens biomicro-scopy, FFA or OCT was performed on the patients in group1 within 2–8 weeks after the operation. Laser photocoagula-tion was added immediately if: (i) OCT showed a localizedretinal detachment at the macula; (ii) contact lens biomicro-scopy examination showed detachment of the macular holeedge; or (iii) FFA showed that the pigment scars around themacular hole were not enough (that is, the adherence ofretina to choroid was not very secure).

The data was analysed with Statistical Package for theSocial Sciences (SPSS, Chicago, IL, USA) by the methods ofanalysis of variance (ANOVA), χ2 test and Fisher’s exact test.P ≤ 0.05 was considered as statistically significant.

Table 1. Patient characteristics and baseline examination data

Characteristic Group 1 Group 2 Group 3 P value

Total no. eyes 46 12 7Age (years; mean ± SD) 52.5 ± 13.6 51.7 ± 14.8 54.3 ± 7.6 0.5466Sex†

Male 7 2 2Female 39 10 5

Affected eye†

Left 22 7 3Right 24 5 4

Refraction (D; mean ± SD) –14.8 ± 4.2 –15.7 ± 5.8 –15.8 ± 4.9 0.3432Axial length (mm; mean ± SD) 28.9 ± 1.7 29.2 ± 1.9 29.3 ± 1.5 0.4329Symptom duration (days; mean ± SD) 20.4 ± 10.3 19.6 ± 9.9 18.5 ± 9.6 0.2345Extent of retinal detachment†

PS 13 3 3PS + inferior 23 7 4PS + inferior + superior 5 1 0Peripheral retinal tear 5 2 1

†Data were not analysed because the samples were too small. Group 1, gas tamponade plus laser photocoagulation; group 2, gas tamponadeonly; group 3, silicone oil tamponade only. PS, posterior staphyloma.

Highly myopic RD with macular hole 263

RESULTS

Patient characteristics and baseline examination data aresummarized in Table 1. There was no statistically significantdifference among the groups in age, sex, symptom duration,preoperative refractive condition, axial length and extent ofretinal detachment.

In group 1, 12 eyes were confirmed by FFA or OCT ashaving an adherence of the retina to the choroid that wasnot very secure. Argon laser photocoagulation was addedfor these patients. Primary retinal reattachment wasachieved in 43 eyes (93.5%). Visual acuity of 6/60 or morewas achieved in 24 eyes (52.2%). Retinal redetachmentoccurred in three eyes due to reopening of the macularhole. This was treated by an injection of 0.5 mL pure C3F8

into the vitreous cavity followed by argon laser photo-coagulation 5 days later for two of the three eyes withsuccessful retinal reattachment. The third patient refusedfurther treatment. The edge of the macular hole could beseen in all cases in the early postoperative phase in thisgroup, but the holes were completely closed in 18 eyes at2 months or later (Fig. 1). A markedly thin fibrous mem-brane could be observed in the bed of the macular hole in15 eyes (Fig. 2).

In group 2, primary retinal attachment was achieved inseven eyes (58.3%) and visual acuity was 6/60 or more in sixeyes (50.0%). Further vitreous surgery in conjunction with

photocoagulation was undertaken in four of five eyes withredetachment. Silicone oil tamponade was applied in threeeyes and gas tamponade was applied in one eye. One patientrefused further treatment. Under indirect ophthalmoscopyand/or a contact three-mirror lens examination, the edge ofthe macular hole was seen in all cases in this group immedi-ately after the operation and one hole was completelyclosed 4 months later.

In group 3, shallow retinal detachment developed in oneeye 2 weeks after silicone oil tamponade. Retinal redetach-ment occurred in two eyes after removal of silicone oil.Primary retinal attachment was achieved in four eyes (57.1%)and visual acuity was 6/60 or more in three eyes (42.9%). Theedge of the macular hole was seen in all patients duringindirect ophthalmoscopy and/or a contact three-mirror lensexamination in this group during the follow up.

Table 2 shows the primary surgical success rate in eachgroup. The success rate of reattachment was significantlyhigher in group 1 than in group 2 and 3. However, there wasno significant difference in regard to postoperative visualacuity among the groups.

Table 3 lists the complications among the groups. Ingroup 1, the intraoperative complications were retinal dothaemorrhage (three eyes) and shallow anterior chamber(two eyes), which was attributable to the manipulationintended to completely eliminate the subretinal fluid. Thedepth of the anterior chamber became normal after 1 day

Figure 1. The optical coherence tomograph of a macula post-operatively. The macula hole was closed.

Figure 2. Fundus appearance of the macula postoperatively. Themacula hole was closed. A thin fibrous membrane could beobserved in the macular hole (→).

Table 2. Primary surgical success rate and resultant visual acuity

No. eyes (%) P value Group 1 Group 2 Group 3 P1–2 P2–3 P1–3

Successful attachment 43 (93.5) 7 (58.3) 4 (57.1) 0.0075* 0.6634 0.0248*Visual acuity ≤ 6/60 24 (52.2) 6 (50.0) 3 (42.9) 0.8932 0.5700 0.9573

*P ≤ 0.05. Group 1, gas tamponade plus laser photocoagulation; group 2, gas tamponade only; group 3, silicone oil tamponade only.

264 Lu et al.

postoperatively. There were no intraoperative complica-tions in group 2 or group 3.

The postoperative complication of epiretinal membraneformation was found in one eye each of group 1 and group2. The most severe complication was an increase in nuclearsclerosis, seen in nine eyes (19.6%) in group 1, three eyes(25.0%) in group 2 and four eyes (57.1%) in group 3.Cataract surgery was performed in one eye from group 1and two eyes from group 3 during the follow-up period, andthe final visual acuity was more than 6/60.

DISCUSSION

At present, the mechanism of retinal detachment in highlymyopic eyes with a macular hole is unclear. However, themain reasons for surgical failure may involve the presence ofposterior staphyloma, atrophy of the RPE and tangentialtraction of the epiretinal membrane. One of the most seriouscomplications of the operation was the failure to close or thereopening of the macular hole. Therefore, the importance ofinitial surgical success (i.e. hole closure) should be emphasized.

Vitreous surgery combined with photocoagulation couldreduce the vitreous traction and increase the macular adher-ence to the choroid. In our study, anatomical reattachmentof the retina was achieved in 43 of 46 eyes in group 1 incontrast to seven of 12 eyes in group 2 and four of seveneyes in group 3. The initial retinal attachment rate wassignificantly higher in group 1 than in group 2 (P = 0.0075)and group 3 (P = 0.0248). The surgical results were compa-rable to previous reports regarding vitrectomy for retinaldetachment with macular holes in high myopia.3–5 How-ever, there was no significant difference in the final visualacuity among the groups and no significant relationship wasfound between successful retinal reattachment and thechoice of gas tamponade agent.

In evaluating the condition of the macular hole, OCTwas more helpful than FFA. Optical coherence tomographycould not only show whether the macular hole was com-pletely closed, but could also indicate if the macula wasadhered to the choroid in a case where the macular hole wasnot completely closed. The holes were evaluated by contactlens biomicroscopy and FFA where OCT was not available.

Laser photocoagulation should be added if the macula wasnot adhered to the choroid or the macular hole was notclosed completely.

Gass suggested that the closure of the macular hole wasthe result of centripetal movement of previously displacedparacentral photoreceptors, not simple reapproximation ofthe retinal edge to the RPE.14 Hainsworth et al. confirmedthis mechanism happened in the course of macular holeclosure.15 Perhaps there is a different situation in highmyopia. Macular holes are more difficult to close com-pletely in high myopia than in idiopathic cases. Centripetalmovement of paracentral photoreceptors may be less effec-tive because of thin retina and rare paracentral photo-recep-tors resulting from RPE atrophy in the staphyloma, orsurface traction more difficult to relieve because of thestaphyloma.

Ohana and Blumenkranz applied photocoagulationdirectly to the RPE in a circular pattern just inside the edgeof the macular hole in selected patients with persistent orreopened macular holes after vitrectomy in the hope ofstimulating the wound-healing response.12 Macular holeswere completely closed in 16 eyes, although an epiretinalmembrane was not removed in most of the patients in thestudy. In addition, there was a thin fibrous membrane on thesurface of the macular holes in seven eyes.

All of these observations support the contention thatphotocoagulation stimulated the wound-healing response inhighly myopic macular holes. An adequate wound healingresponse may be one of the important mechanisms ofclosure of macular holes in high myopia.

REFERENCES

1. Aaberg TM, Blair CJ, Gass JDM. Macular holes. Am. J. Ophthal-mol. 1970; 65: 555–61.

2. Smiddy WE, Michels KG, de Bustros S et al. Histopathology oftissue removed during vitrectomy for impending idiopathicmacular holes. Am. J. Ophthalmol. 1989; 108: 360–64.

3. Stripe M, Michels RG. Retinal detachment in highly myopiceyes due to macular holes and epiretinal traction. Retina 1990;10: 113–14.

4. Seike C, Kusaka S, Sakagami K, Ohashi Y. Reopening ofmacular holes in highly myopic eyes with retinal detachments.Retina 1997; 17: 2–6.

5. Oshima Y, Ikuno Y, Motokura M et al. Complete epiretinalmembrane separation in highly myopic eyes with retinaldetachment resulting from a macular hole. Am. J. Ophthalmol.1998; 126: 669–76.

6. Lansing MB, Glaser BM, Liss H et al. The effect of pars planavitrectomy and transforming growth factor-beta 2 withoutepiretinal membrane peeling on full-thickness macular holes.Ophthalmology 1993; 100: 868–71.

7. Glaser BM, Michels RG, Kuppermann BD et al. Transforminggrowth factor-beta 2 for the treatment of full-thicknessmacular holes. A prospective randomized study. Ophthalmology1992; 99: 1162–72.

Table 3. Intraoperative and postoperative complications

Complication No. eyes (%) Group 1 Group 2 Group 3

Intraoperative complicationsRetinal haemorrhage 3 (6.5) 0 0Shallow anterior chamber 2 (4.3) 0 0

Postoperative complicationsEpiretinal membrane formation 1 (2.2) 1 (8.3) 0Cataract 9 (19.6) 3 (25.0) 4 (57.1)

Group 1, gas tamponade plus laser photocoagulation; group 2,gas tamponade only; group 3, silicone oil tamponade only.

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8. Liggett PE, Skolik DS, Horio B et al. Human autologous serumfor the treatment of full-thickness macular holes. A prelimi-nary study. Ophthalmology 1995; 102: 1071–6.

9. Korobelnik JF, Hannouche D, Belayachi N et al. Autologousplatelet concentrate as an adjunct in macular hole healing: apilot study. Ophthalmology 1996; 103: 590–94.

10. Goldbaum MH, McCuen BW, Haneken AM et al. Silicone oiltamponade to seal macular holes without position restrictions.Ophthalmology 1998; 105: 2140–48.

11. Del Priore LV, Kaplan HJ, Bonham RD. Laser photocoagula-tion and fluid–gas exchange for recurrent macular hole. Retina1994; 14: 381–2.

12. Ohana E, Blumenkranz MS. Treatment of reopened macularhole after vitrectomy by laser and outpatient fluid–gasexchange. Ophthalmology 1998; 105: 1398–403.

13. Ikuno Y, Kame M, Ohno T et al. Photocoagulation andfluid–gas exchange for persistent macular hole. Retina 1996;16: 264–6.

14. Gass JDM. Reappraisal of biomicroscopic classification ofstages of development of macular hole. Am. J. Ophthalmol. 1995;119: 752–9.

15. Hainsworth DP, Johnson MW, Jaffe GJ. Sustained closure ofsurgically repaired macular holes after retinal detachment withsubmacular fluid. Am. J. Ophthalmol. 1997; 123: 364–9.