Retina Retina

Decision Making in Rhegmatogenous Retinal Detachment

B.P. Guliani MS

B.P. Guliani MS, Sandeep Gupta MBBS Vardhman Mahavir Medical College, Safadrjung Hospital New Delhi

A

s we all know that Retinal detachment is separation of neurosensory retina (NSR) from Retinal Pigment epithelium (RPE). If it occurs due to one or more fullthickness retinal breaks it is called Rhegmatogenous retinal detachment (RRD).

Important definitions 1. Retinal break means retinal tear or a retinal hole. 2. Retinal tears are usually associated with well-defined vitreoretinal traction either on an attached flap or operculum. 3. Retinal holes occur more commonly as a result of localized retinal atrophy and are not associated with vitreoretinal traction. 4. Symptomatic tear is a tear caused by posterior vitreous detachment in the eye of a patient complaining of light flashes (photopsias) and/or floaters (entopsias). 5. Atrophic round hole in lattice degeneration in a patient with floaters should not be considered to be symptomatic, since it is unrelated to the posterior vitreous detachment. 6. Fresh tear is either a symptomatic tear or a tear found in a location where no tear was seen on prior ophthalmic examination. 7. Giant tear is defined as a tear which is 900 or larger. 8. Subclinical (RD) defined as having less than 1–2 disc diameter (DD) of associated sub retinal fluid (SRF) and usually do not progress.

Prevention of RD Why is it important to discuss or practice prevention of RD? 1. Initial surgical attempts to reattach the retina fail in approximately 10–20% of cases.

2. Reoperations are unsuccessful in as many as 50% of cases. 3. Anatomical success is significantly less common in eyes with features suggesting an increased risk of proliferative Vitreoretinopathy (PVR). 4. Following anatomically successful surgery, visual acuity returns to 20/50 or better in only approximately 50% of cases.

How one can prevent RD1,2? By the use of laser photocoagulation (LIO) or cryotherapy which create a chorioretinal adhesion around both visible sites of vitreoretinal adhesion and retinal breaks. This is frequently successful in sealing the treated lesion and preventing it from causing a clinical RD. One must be careful as extensive laser or cryo may cause vitreous changes that actually increase the chances of subsequent vitreoretinal traction and retinal detachment.

What type of tears / flaps should be sealed? Though there are no clinical trials available for this but following guidelines may be helpful in deciding whether to treat or not treat. 1. Symptomatic tears in patients with no history of Retinal Disease

•

Flap (Horseshoe) Tears are associated with symptoms and are dangerous. 25-90 % have been found to cause retinal detachment. Flap tears associated with vitreous haemorrhage are more prone to develop RD. Studies shows only fresh tears are dangerous. Prophylactic treatment of symptomatic flap tears has been shown to reduce the incidence of RD to 0-19%. Such treatment therefore seems justified.

www. dosonline.org l 33

Retina



•

Operculated tears are less likely to cause detachment than fresh flap tears. Fresh operculated tears are largely benign, it does not seem reasonable to treat them all. Those that are either large or located superiorly are most likely to cause detachment and should therefore be treated. Moreover, in evaluating operculated tears for therapy, it is very important to examine the vitreous carefully with the Goldmann 3-mirror lens. If vitreous is adherent to the edge of the round hole, the hole should be considered the equivalent of a flap tear and should be treated.

2. Asymptomatic breaks in patients with no history of retinal disease

•

Flap Tears: Eyes with asymptomatic flap tears have been shown to have a very low incidence of subsequent retinal detachment. The evidence indicates that patients with asymptomatic flap tears are not highly prone to retinal detachment. Almost all such tears can be followed without treatment.



•

Asymptomatic Round Holes, with or Without Operculum: These holes have been found to be harmless in several series. There is no evidence that such tears should be treated.



•

Lattice Degeneration Without Holes Lattice degeneration is a known precursor of retinal detachment, as vitreous traction on its posterior edge may cause a horseshoe tear and are found in approximately 30% of patients who undergo retinal detachment surgery. No treatment is indicated for lattice degeneration without holes.



•

Lattice Degeneration with Holes Lattice degeneration with holes is more likely to lead to detachment than is lattice degeneration without holes, because of the possibility of fluid seepage under the retina. Nevertheless, the risk is not great. 2-3 %population have lattice degeneration with holes, but they never develop retinal detachment. Therefore, prophylactic therapy of lattice degeneration with holes in low risk is not indicated.

3. Breaks in Aphakic Eyes Since approximately 2% of all aphakic eyes develop retinal detachment, 50% of which occurs in first years; they should be carefully examined for retinal holes and early aphakic retinal detachment. Observation is particularly important during the first year following cataract surgery, when 50% of the detachments occur. Breaks in aphakic eyes are more common than in phakic eyes. 4. Breaks in Fellow Eyes

•

Phakic Fellow Eyes Several studies have shown the bilateral incidence of retinal detachment to

34 l DOS Times - Vol. 19, No. 3 September, 2013

be 10%. If prophylaxis is effective, this easily identifiable high-risk group should benefit from treatment. Clearly then, fellow eyes are at very high risk of retinal detachment. The risk is still higher if there are peripheral vitreoretinal abnormalities. Several studies have shown that prophylaxis of such abnormalities is beneficial. Therefore, all full-thickness retinal holes, lattice degeneration and vitreoretinal tags with traction in second eyes should be treated. Following the introduction of prophylactic therapy, the incidence of retinal detachment in fellow eyes decreased from 11% to 3%.

•

Aphakic Fellow Eyes The incidence of retinal detachment in aphakic fellow eyes is 2-3 times that of phakic fellow eyes (21-36% as compared to 10%) Aphakic fellow eyes with retinal breaks are thus particularly prone to retinal detachment. In such eyes we treat all retinal breaks, as well as lattice degeneration and vitreoretinal tags.

5. Giant Tears At Moorfields Eye Hospital, it has been determined that 48% of patients who have a giant tear in one eye, will have a subsequent retinal detachment in the other eye. Since retinal detachments with giant tears are among the most difficult detachments to repair, prevention of detachment in the second eye is very important. At Moorfields, even if it has no clinically apparent vitreoretinal abnormalities, the peripheral retina of the fellow eye is treated with circumferential cryotherapy. 6. Breaks in Myopic Eyes Because highly myopic eyes are much more likely to develop retinal detachment than non myopic eyes, some surgeons treat all breaks found, even asymptomatic round holes. There are 35 myopic eyes with breaks for every myopic eye which develops a retinal detachment. The evidence however does not support prophylactic treatment of retinal breaks found in asymptomatic myopic eyes. 7. Breaks in Senile Retinoschisis On routine autopsy examination of eyes with no history of ocular disease, 2.4% were found to have senile retinoschisis. Because of the low incidence of retinal detachment and because retinal detachments caused by retinoschisis progress slowly, it is not necessary to treat all outer wall holes. Schepens suggests treatment of only large, multiple, or posteriorly located outer wall breaks. Clearly, then, prophylactic therapy applied to patients who can be identified as likely to develop detachment accomplishes far more than less selective treatment. We suggest, therefore, that such treatment, with its attendant hazards [as Central retinal artery occlusion (CRAO)

Retina

Figure 1: Flow chart of proplylactic treatment for prevention of retinal detachment

following block, macular pucker following laser and cryotherapy], is indicated only for eyes with a significant risk of retinal detachment (Figure1), i.e., eyes with symptomatic flap tears and fellow eyes with vitreoretinal abnormalities. Symptomatic operculated tears, asymptomatic breaks in aphakic eyes and outer wall holes in retinoschisis might occasionally be treated if they are large or posteriorly located. Asymptomatic breaks in phakic eyes and lattice degeneration with and without holes should rarely be treated unless the patient is not likely to perceive an early retinal detachment or to return for follow up examinations. Currently, RRD continues to be an important cause of visual loss. Three factors predispose to development of RRD: 1. Existence of a liquefied vitreous gel 2. Tractional forces that precipitate a retinal break 3. Presence of retinal break through which fluid may access the subretinal space. The vitreous is firmly attached to the vitreous base, an area 3–6 mm in diameter that straddles the ora serrata surrounding the retina. The posterior border of the vitreous base is located both more posteriorly and temporally in older individuals. Therefore, retinal tears may occur at a higher frequency at the temporal periphery in such patients, following posterior vitreous detachment (PVD)3. PVD usually presents as an acute event, and is more prevalent in patients older than 50 years, with frequencies as high as 53%. PVD often precipitates RRD because the tractional

forces necessary to generate retinal breaks are produced upon development of PVD, although not all retinal breaks progress to detachment4. The reported incidence of retinal tears in patients with acute symptomatic PVD varies from 8–46%5.

Trends in RRD surgery The fundamental principles involved in reattachment of a retina include identification of all retinal breaks, and relief of the vitreous traction. Traditionally, scleral buckling (SB) was viewed as the gold standard treatment for uncomplicated RRD. Pars plana vitrectomy (PPV) was traditionally reserved for treatment of eyes with complications (Table 1), such as those showing giant retinal tears or exhibiting significant proliferative Vitreoretinopathy (PVR). As the view of the retinal periphery is enhanced, identification of retinal breaks is rendered easier, achievement of complete intraoperative retinal attachment is possible, the risks of hemorrhage or retinal incarceration inherent to the external drainage procedure applied during SB is eliminated. PPV is less likely to cause a refractive change with the recent introduction of small-gauge vitrectomy ie micro incision vitreous surgery (MIVS), vitrectomy surgery is less invasive, affords fast recovery, and is sutureless. In the 1980s, the indications for PPV in RRD patients were broadened to include less complicated instances, and the term “primary vitrectomy” was introduced by Klöti. As the necessary instrumentation for, and safety of, PPV continue to improve with developments in microscope technology, intensified endoillumination, and wide-angle viewing systems, the

www. dosonline.org l 35

Retina

Table 1: Complications

Pneunoretinopexy

Scleral buckling

Primary vitrectomy

Incarceration of vitreous: 1.4%

Recurrent retinal detachment

Relatively high rates of iatrogenic retinal breakage (0.78–24%)

Sub conjuctival gas: 1.1%

Epiretinal membrane (ERM)

Crystalline lens damage (0.03–9%)

New or missed breaks: 13.3%

Extrusion of explants

Retinal incarceration at retinotomy sites (0.6–2.9%)

PVR: 4.6%

Glaucoma

Corneal abrasion (0.6%),

Redetachment: 3.0%

Infection of explants

Choroidal effusion (0.5%), as reported in one national audit

Mild macular pucvker: 1.8%

Band migration

Transient or persistent intraocular pressure increases have been reported in 15–24% of patients

Persistent sub retinal fluid: 2.1%

Anterior segment ischemia

Phakic patients are at significant risk of developing nuclear cataracts; this is especially true of patients older than 50 years (21–86%).

Minimal ERM: 1.4%

Diplopia

Retinal redetachment, with or without PVR, usually by new or missed breaks, or reopening of former breaks. Recent advances in surgical technology, including the development of MIVS and wide-angle viewing systems, have reduced the frequency of anatomic failures

Re-opening of original break: 1.1%

Cystic macular edema, macular pucker, and macular hole

Vitreous haze: 1.1%

Although very rare, endophthalmitis has been reported, as has sympathetic ophthalmia. The incubation period for the latter condition after vitrectomy varies from 4 weeks to 2 years

indications for vitrectomy in RRD have been further expanded to include most patients with RRD. Indeed, PPV is more useful than SB in eyes requiring simultaneous cataract extraction or those of pseudophakic status. Whatever method is used one must remember that: 1. In “macular on” retinal detachment, urgent surgery should generally be scheduled to prevent detachment of the macula. 2. Cases with tractional tears tend to progress very rapidly and should be treated urgently. 3. Asymptomatic retinal detachments and detachments without tractional breaks e.g., those due to retinal dialyses, atrophic retinal breaks in young myopes progress more slowly hence some delay, if it allows optimal conditions for surgery, may then be acceptable6. Techniques used for Rhegmatogenous Retinal reattachment surgery •

Scleral buckling (SB)

•

Pneumatic retinopexy (PR)

•

Primary Pars plana Vitrectomy (PPV)

36 l DOS Times - Vol. 19, No. 3 September, 2013

Decision making in rhegmatogenous retinal detachment is difficult to answer because there is no large scale clinical trial that has shown statistically significant differences among these treatment options. The aim of this paper is to teach pros and cons of these retinal re-attachment surgical techniques. Further recent studies make things more clear. Ultimately choice depends on socioeconomic status, availability of instrumentation and type of presentation and surgeons skills. At the time of decision making one should not forget to assess patient outcomes including postoperative pain and discomfort, time away from work, and quality-of-life to choose what is the best treatment option: pneumatic retinopexy, scleral buckle, vitrectomy or a combination of PPV with buckling. Prospective data for a direct comparison of PR to primary vitrectomy are unavailable. Vitrectomy is the procedure of choice in dealing with significant PVR and vitreoretinal traction, and it may be ideal when vitreous or capsular opacity causes poor visualization. Vitrectomy tends to induce cataract, it is used most commonly in pseudophakic eyes. Tiny breaks, common in pseudophakic eyes, may be most readily identified by internal search during vitrectomy. Vitrectomy yields significantly better single-operation success rates than SB in pseudophakic eyes. In phakic eyes, vitrectomy

Retina

yielded poorer visual results than SB with no benefit in single-operation success.

Comparison of surgical outcome of surgical techniques i.e SB, PPV, PR SB The anatomical results following scleral buckling for rhegmatogenous retinal detachments are impressive. An overall reattachment rate of at least 90% is achievable. The success rates demonstrated in MUSTARD7 was achieved (in patients aged 51 to 60 years) in 86.72%; the outcome was almost equally positive among very young patients, with success rates of 85.00% in children up to age 10 years and 86.07% in adolescents aged 11 to 20 years.

PR vs. SB8,9 1. The rate of retinal redetachment was found to be 38% in pneumatic retinopexy when compared to 16% in scleral buckling 2. The need for reoperation for retinal detachment was observed to be higher in PR vs SB (38% Vs 14%) 3. The incidence of PVR was found to be 12% in PR when compared to 8% in SB patients. 4. Successful reattachment with one operation was 50% in PR compared to 78% in SB patients. 5. Successful reattachment with one operation was 62% in PR compared to 84% in scleral buckled patients. 6. LogMAR visual acuity at final follow-up (mean) was 0.55 (20/70) in PR patients when compared to 0.41 (20/50) in scleral buckled patients.

PPV vs.SB vs. combined PPV /SB 1. The reported primary success rates for RRD repair by PPV range from 64–94%10,11. 2. Exploiting the recent advances in surgical technology including MIVS, several recent case series reported that the single operation success rate (SOSR) improved to over 90% and that the final average visual acuity was 20/40 or better. 3. Several retrospective series and prospective clinical trials comparing SB, PPV, and/or combined SB/PPV, found no statistically significant difference in SOSR among the various procedures 4. However, a few studies reported that PPV was superior in terms of either anatomic or visual outcome in comparison with SB alone12,13,14. 5. In addition, several reports comparing PPV and combined PPV/SB also found that the use of a combined procedure did not significantly influence anatomical or visual outcomes.

6. A meta-analysis of 29 studies on patients with pseudophakic RD found that both PPV and combined PPV/SB were associated with a higher SOSR and better visual acuity outcomes than was SB alone15,16.

PR vs SB vs PPV17,18 Pneumatic retinopexy (PR) was developed in an attempt to minimize the mentioned problems of SB. This outpatient procedure for retinal reattachment consists of an intravitreal gas injection with transconjunctival cryopexy or laser photocoagulation, followed by appropriate head positioning15. No incisions are required. PR is substantially less expensive than scleral buckling or vitrectomy and has become widely accepted as the treatment of choice for selected retinal detachments, with the vast majority of vitreoretinal surgeons employing this procedure. The multicenter clinical trial conducted as a part of The Retinal Detachment Study Group with 198 patients in 1989. Scleral buckling was compared with pneumatic retinopexy with regard to single-operation reattachment (82 versus 73%), reattachment with one operation and postoperative laser/cryotherapy (84 versus 81%), overall reattachment with reoperations (98 versus 99%), final visual acuity of 20/50 or better in eye with preoperative detachment of the macula for 2 weeks or less (56 versus 80%), PVR (5 versus 3%), and new retinal breaks (13 versus 23%). Excluded were cases with breaks larger than 1 clockhour or multiple breaks extending over more than 6 clockhour of the retina, breaks in the inferior 4 clock-hours of the retina, presence of PVR grade C or D (Retina Society Terminology Committee, 1983)13,14 physical disability or mental incompetence precluding maintenance of the required positioning, severe or uncontrolled glaucoma and cloudy media precluding full assessment of the retina. Comparing PR with SB, postoperative morbidity was less and had a shorter duration in the PR group, cataract surgery was required four times more often after SB. New and missed retinal breaks occurred more frequently after PR but did not usually produce an unfavourable outcome new and missed retinal breaks after SB had the worst prognosis & postoperative proliferative vitreoretinopathy occurred in 5% in the SB group and 3% in the PR group (not statistically significant).

Important studies 1. One hundred seventy six surgeons from 48 countries spanning five continents provided information on the primary procedures for 7678 cases of RRDs including 4179 patients with uncomplicated RRDs. It states that it is reasonable to conclude that in phakic eyes, sclera buckle alone can be considered. However, in pseudophakic eyes, there is no clear winner and the surgeon should consider higher risk of level 3 failure with scleral buckle versus higher risk of level 2 failure with vitrectomy. Pneumatic retinopexy was found to be

www. dosonline.org l 37

Retina

equivalent to scleral buckle in cases where the retinal detachment was induced by atrophic holes. However, in cases where a flap tear is present, scleral buckle has a lower failure rate than pneumatic retinopexy. Given this information, pneumatic retinopexy may be considered in cases of retinal detachment with grade 0 or grade A PVR and atrophic holes7. It studied the outcome of the treatment of complex rhegmatogenous retinal detachments The main categories evaluated in this investigation were: (1) grade B proliferative vitreoretinopathy (2) grade C-1 PVR, (3) choroidal detachment or significant hypotony (4) large or giant retinal tears, and (5) macular holes. It showed that when grade B PVR is present, performing a vitrectomy, with or without a supplemental buckle is better than applying a scleral buckle alone. However, when grade C-1 PVR is present, no significant difference in the level 1 failure rate is seen when comparing these techniques for repair. There was no statistical difference in the level 1 failure rate between gas and silicone oil when vitrectomy was performed in eyes with grade B or C-1 PVR. When choroidal detachment or hypotony was present, performing a vitrectomy led to a much better result than not performing one7. 2. A Retrospective, nonrandomized, interventional case series to compare pars plana vitrectomy (PPV) with combined PPV and scleral buckle (SB) for the repair of noncomplex primary rhegmatogenous retinal detachment (RRD) reviewed 181 consecutive cases of vitrectomy for primary RRD at 2 major medical centres in Israel. In phakic eyes, SSAS (single surgery anatomic success) rates were 92% and 87.5%, respectively, and in pseudophakic eyes, SSAS rates were 77.5% and 86.7%, respectively, in the PPV and PPV plus SB groups. Final VA was 0.41 (20/51) in the PPV group and 0.53 (20/68) in the PPV plus SB group. The reattachment rate and the final VA were similar in both groups. The addition of SB did not improve the results and was associated with slightly lower VA than with PPV alone. Tear location or lens status had no significant effect on success rates. It is likely that in eyes undergoing PPV for primary RRD, addition of a SB is not warranted19. 3. MUSTARD: Munster Study on Therapy Achievements in Retinal Detachment20 was conducted to evaluate the anatomic success rates of scleral buckling surgery in the treatment of rhegmatogenous retinal detachment with 4325 subjects who underwent surgery between 1980 and 2001, established an overall success rate of approximately 84% in cases with rhegmatogenous retinal detachment by the first buckling procedure7,11.

References 1. Benson WE. Prophylactic therapy of retinal breaks. Survey of Ophthalmology. 1977;22 (1):41–7.

38 l DOS Times - Vol. 19, No. 3 September, 2013

2.

Retina 5th edition Stephen J Ryan MD (VOLUME 3)

3. Steinberg RH: Research update: report from a workshop on cell biology of retinal detachment. Exp Eye Res. 1986; 43:695-706 4.

Leaver PK, Cleary PE: Macular hole and retinal detachment. Trans Ophthalmol Soc UK. 1975; 95:145-147

5.

Heimann H, Bartz –Schimidt KU, Bornfeild N, et al. Scleral buckling versus PPV in RRD: a prospective randomized multicentre clinical study. Ophthalmology 2007;114:2142-54

6.

Schwartz SG, Flynn HW. Primary retinal detachment: sclera buckle or pars plana vitrectomy? Curr Opin Ophthalmol. 2006; 17:245–50.

7. Thelen U, Amler S, Osada N, et al. Outcome of surgery after macula-off retinal detachment - results from MUSTARD, one of the largest databases on buckling surgery in Europe, Acta Ophthalmol. 2012;90(5):481-6. 8.

Heimann H, Bartz-Schmidt KU, Bornfeld N, et al. Scleral Buckling versus Primary Vitrectomy in rhegmatogenous retinal detachment: a prospective randomized multicenter clinical study. Ophthalmology 2007; 114:2142-2154.

9. Brazitikos PD, Androudi S, Christen WG, et al. Primary pars plana vitrectomy versus scleral buckle surgery for the treatment of pseudophakic retinal detachment: a randomized clinical trial. Retina 2005; 25:957-964. 10. Sharma YR, Karunanithi S, Azad RV, et al. Functional and anatomic outcome of scleral buckling versus primary vitrectomy in pseudophakic retinal detachment. Acta Ophthalmol Scand. 2005; 83:293-297. 11. Halberstadt M, Chatterjee-Sanz N, Brandenberg L, et al. Primary retinal reattachment surgery: anatomical and functional outcome in phakic and pseudophakic eyes. Eye (Lond) 2005; 19:891-898. 12. Azad RV, Chanana B, Sharma YR, et al. Primary vitrectomy versus conventional retinal detachment surgery in phakic rhegmatogenous retinal detachment. Acta Ophthalmol Scand. 2007; 85:540-545. 13. Arya AV, Emerson JW, Engelbert M, et al. Surgical management of pseudophakic retinal detachments: a meta-analysis. Ophthalmology 2006; 113:1724-1733. 14. Hilton GF, Grizzard WS. Pneumatic retinopexy. A two-step outpatient operation without conjunctival incision. Ophthalmology 1986; 93:626-641 15. Tornambe PE, Hilton GF. The Retinal Detachment Study Group: Pneumatic retinopexy: a multicenter, randomized, controlled clinical trial comparing pneumatic retinopexy with scleral buckling. Ophthalmology 1989; 96:772-783 16. Retina Society Terminology Committee: The classification of retinal detachment with proliferative vitreoretinopathy. Ophthalmology 1983; 90:121-125. 17. Chen JC, Robertson JE, Coonan P, et al. Results and complications of pneumatic retinopexy. Ophthalmology 1988; 95:601-608. 18. Kinori M, Moisseiev E, Shoshany N, et al. Comparison of pars plana vitrectomy with and without scleral buckle for the repair of primary rhegmatogenous retinal detachment. Am J Ophthalmol. 2011;152(2):291-297. 19. Grizzard WS, Hilton GF, Hammer ME, et al. A multivariant analysis of anatomic success of retinal detachments treated with scleral buckling. Graefes Arch Clin Exp Ophthal. 1994; 232:1-7. 20. Ron A. Adelman, Aaron J. Parnes, Didier Ducournau, Strategy for the Management of Uncomplicated Retinal Detachments: The European Vitreo-Retinal Society Retinal Detachment Study Report 1,2. Ophthalmology 2013;120(9):1804-1808.