Clinical Characteristics and Surgical Outcomes of Pseudophakic and Aphakic Retinal Detachments

(1)

INTRODUCTION

Retinal detachment (RD) is defined as a separa- tion of the neuro-retina from retinal pigment epithe- lium. If untreated, most RD will progress to a com- plete detachment and result in loss of vision of the affected eye. The most important risk factors for RD are RD in the fellow eye, myopia, history of trauma and history of cataract or other intraocular surgery.

The proportion of aphakic or pseudophakic

patients with RD has increased to 30% during the past decade, due to the increasing number of cataract surgery being performed.¹ RD remains common and is the most serious problem after com- plicated or uncomplicated cataract surgery.^2,3

The incidence of RD is about 0.98~3.6% after the intracapsular cataract extraction (ICCE)⁴, 0.33~1.7%^5-9after extracapsular cataract extraction (ECCE) and intraocular lens (IOL) implantation, and 1.17%¹⁰ after phacoemulsification and IOL implantation.

Nowadays, most cataract surgeons perform phacoemulsification in cataract extraction.

Nevertheless, RD remains a common and serious complication in many cases when the posterior capsule is ruptured during surgery or YAG capsulotomy is done due to posterior capsular opacification.

Vol. 18:58-64, 2004

Clinical Characteristics and Surgical Outcomes of Pseudophakic and Aphakic Retinal Detachments

Bo Young Jun, MD, Jae Pil Shin, MD, Si Yeol Kim, MD

Department of Ophthalmology, School of Medicine, Kyungpook National University, Taegu, Korea

We retrospectively evaluated the clinical characteristics and surgical outcomes of 20 pseudophakic retinal detachment (RD) patients (20 eyes) and 17 aphakic RD patients (17 eyes). Males were predominated in both groups. The time interval between cataract extraction and RD was 31 months on average in the pseudophakic group, 32 months with intact posterior capsule and 27 months with ruptured posteri- or capsule, and 148 months in the aphakic group. In 50% of cases with ruptured posterior capsule in the pseudophakic group, RD occurred within 1 year. The anatomic success rate was 95% in the pseudophakic group and 88% in the aphakic group. The most common cause of failure was the development of proliferative vitre- oretinopathy. Visual acuities more than 20/40 after RD surgery were found in 13 pseudophakic (65%) and 6 aphakic (36%) eyes. Aphakic patients were more inclined to have silent RD than pseudophakic patients because of their poor visual acuity.

Post-operative follow-up is required especially for the first 1 year in cases of dam- aged posterior capsule due to the high incidence of RD during this period.

Key words: aphakic retinal detachment, posterior capsule, pseudophakic retinal detach- ment

Reprint requests to Jae Pil Shin, MD, Department of Ophthalmology, Kyungpook National University Hospital, #52 Samduk-dong, Jung-gu, Taegu 700-721, Korea.

This study was presented in part at the 89th Annual Meeting of the Korean Ophthalmological Society, April, 2003.

(2)

There are many reports about the clinical characteristics of pseudophakic and aphakic RD. In pseudophakic RD, though its incidence increases in cases of posterior capsule rupture, a single retinal tear measuring between 1 disc diameter and 1 clock-hour in size is most likely to occur, and these tears are located more posteriorly than in RD with aphakia.

Because of poor mydriasis and any posterior capsular opacification in pseudophakic RD, the visualization of peripheral retina may be less perfect.^10,11

Aphakic patients are more inclined to have silent RD than pseudophakic patients. RD with aphakia is most often related to numerous small holes, less than 1 disc diameter, located between the ora serrata and equator.¹²

We investigated the clinical characteristics and surgical outcomes of aphakic and pseudophakic RD after cataract surgery.

MATERIALS AND METHODS

We reviewed the medical records of 20 pseudophakic and 17 aphakic eyes in which RD developed and which underwent retinal reattachment surgery between January 1994 and June 2002 and were followed up for at least 6 months.

Age, sex, modality for cataract surgery and type of IOL inserted were recorded, as was the time interval between cataract operation and diagnosis of RD. The status of the posterior capsule, intact or not, a history of YAG capsulotomy, and the interval between the capsulotomy and RD were carefully noted. This information was obtained, for each case, by a letter from the referring ophthalmologist.

Best corrected visual acuity (VA) using Snellen chart was obtained preoperatively and postoperatively. Fundus examination with detailed binocular

indirect ophthalmoscopy with indentation and Goldman 3 mirror lens was performed in every case to search for any retinal break. Information regard- ing the number, size, type, and location of retinal breaks as well as the location and extent of RD was recorded. The presence or absence of macular detachment was also recorded.

The history of ocular trauma and medical diseases other than RD was also recorded.

The surgical method of retinal reattachment surgery and outcomes of primary surgery were evaluated. If primary reattachment surgery failed, we analyzed the cause of surgical failure such as proliferative vitreoretinopathy (PVR). The success of primary reattachment surgery was defined as anatomical retinal reattachment for at least 6 months.

All clinical data from 37 patients were analyzed using student T-test.

RESULTS

There were 12 males and 8 females in the pseudophakic RD patients, a male-female ratio of 3:2, and 14 males and 3 females in aphakic RD, a male-female ratio of 4.7:1. The mean patient age was 55.7 years in the pseudophakic patients and 41.2 years in the aphakic patients.

In the pseudophakic RD patients, 8 eyes were diagnosed with RD after phacoemulsification and PC- IOL (posterior chamber IOL) implantation, 10 eyes after ECCE and PC-IOL implantation and 2 eyes after ECCE and scleral fixation of IOL. No ACL (anterior chamber lens) implantation was performed.

In the aphakic RD patients, 9 were diagnosed with RD after ICCE and 8 after ECCE (Table 1).

The time interval between cataract surgery and diagnosis of RD ranged from 24 to 48 months in 7

Table 1. Operation methods for cataract extraction

Methods No. of eyes

Pseudophakia Phacoemulsification with PCL implantation 8 (21.6%) ECCE with PCL implantation 10 (27%)

ECCE with scleral fixation 2 (5.4%)

Aphakia ICCE 9 (24.3%)

ECCE 8 (21.6%)

PCL: posterior chamber lens, ECCE: extracapsular cataract extraction, ICCE: intracapsular cataract extraction

(3)

pseudophakic eyes (35%) and was more than 48 months in 13 aphakic eyes (76%). The mean time interval was 31 months in pseudophakic eyes and 148 months in aphakic eyes (p < 0.05) (Table 2).

Among pseudophakic eyes, the posterior capsule was intact in 14 eyes (70%) and was ruptured during cataract surgery in 4 eyes (20%), while 2 eyes (10%) underwent posterior capsulotomy with Nd:YAG laser after cataract surgery. Therefore the posterior capsule was not intact in 6 eyes (30%) of the pseudophakic group. The posterior capsule was damaged in all aphakic eyes (17 eyes).

The time interval of RD and cataract surgery in eyes with an intact posterior capsule was compared to that of damaged posterior capsule in the pseudophakic group. The time interval between cataract surgery and RD was more than 24 months in 8 (57%) of the 14 eyes with intact posterior capsule, mean 32 months, and within 12 months in 3 (50%) of the 6 eyes with damaged posterior capsule, mean 27 months. RD developed earlier in eyes with damaged posterior capsule than in eyes with intact posterior capsule, but the difference was not statisti- cally significant (p > 0.05).

In pseudophakic RD, we found a single retinal break preoperatively in 9 patients (45%), 2 or more retinal breaks in 4 patients (20%), and no retinal break in 7 patients (35%). In aphakic eyes, there was a single retinal break in 12 eyes (71%) and no retinal break in 5 eyes (29%).

The most common type of retinal break found in both groups was a horseshoe tear and most retinal tears were found in the superotemporal quadrant in more than 50% of the cases (Table 3).

The extent of RD more than 3 quadrants was seen in 7 pseudophakic eyes (35%) and 12 aphakic eyes (70%). Macula was involved in 14 pseudophakic eyes (70%) and 14 aphakic eyes (83%).

Proliferative vitreoretinopathy was found in 5 pseudophakic eyes (25%) and 7 aphakic eyes (41%). A history of ocular trauma was found in 2 pseudophakic eyes (10%) and 9 aphakic eyes (53%) (Table 3).

With regard to primary surgical procedure for the pseudophakic group, scleral buckling was performed in 8 eyes (40%) and pars plana vitrectomy in 12 eyes (60%). In secondary operation, scleral buckling was performed in 2 eyes and pars plana vitrectomy in 1 eye. In the aphakic group, scleral buckling was performed in 4 eyes (24%), and pars plana vitrectomy in 13 eyes (76%). The methods of secondary surgical procedure were scleral buckling in 1 eye and pars plana vitrectomy in 4 eyes.

The success rate of primary retinal reattachment surgery was 80% in pseudophakic RD and 65% in aphakic RD. The overall success rate was 95% and 88%, respectively. Proliferative vitreoretinopathy (5 eyes) was the most common cause of the failure of primary reattachment surgery. The malposition of scleral buckle material (3 eyes) and the change of the buckle effect (2 eyes) were also reasons for secondary surgery. Among the cases of failed reattachment after second operation, 1 eye failed due to recurred proliferative vitreoretinopathy and the other 2 patients refused reoperation.

A final VA more than 20/40 was found in 6 eyes (100%) without macula involvement and in 7 eyes (50%) with macula involvement in pseudophakic Table 2. Time interval between cataract extraction and retinal detachment

Interval (months) No. of eyes

Pseudophakia(20) Aphakia(17) Total(37)

< 6 3(15%) 1 (6%) 4 (11%)

6-12 2(10%) 1 (6%) 3 (8%)

12-24 4(20%) 2 (12%) 6 (16%)

24-48 7(35%) 0 (0%) 7 (19%)

> 48 4(20%) 13 (76%) 17 (46%)

Average (months) 31* 148* 78

*: p < 0.05 by student t-test

(4)

RD patients. In aphakic RD patients, a final VA more than 20/40 was found in 2 eyes (67%) without macula involvement and in 4 eyes (29%) with macula involvement. A final VA less than 20/200 was found in 2 eyes in pseudophakic RD and in 3 eyes in aphakic RD. The cause of poor postoperative visual recovery was neovascular glaucoma with recurrent PVR in 1 eye and macular degeneration in 1 eye in pseudophakic RD. In aphakic RD, the cause of poor visual recovery was vitreous opacity in 1 eye, optic atrophy due to glaucoma in 1 eye, and bullous keratopathy in 1 eye (Table 4).

DISCUSSION

Sun and Lee¹³reported that the rate of RD after ECCE is higher than after phacoemulsification and Wilkinson¹⁴ reported that the incidence of pseudophakic RD is higher than aphakic RD.

The fact that males tend to develop RD more than females has been noted.¹⁵Aphakic males are also more prone to develop RD.¹⁶This phenomenon was also observed in our study.

Ho and Tolentino¹⁷reported that pseudophakic RD occurs at 15~16 months after cataract surgery on average. Hwang et al¹⁸reported that pseudophakic RD occurs at 9.6 months on average. Yoshida et Table 3. Characteristics of retinal detachment

No. of eyes

Pseudophakia Aphakia Total

No. of breaks

single 9 (45%) 12 (71%) 21 (57%)

multiple 4 (20%) 0 (0%) 4 (11%)

none observed 7 (35%) 5 (29%) 12 (32%)

Location

superotemporal 7 (54%) 6 (50%) 13 (52%)

inferotemporal 2 (15%) 3 (25%) 5 (20%)

superonasal 2 (15%) 1 (8%) 3 (12%)

inferonasal 2 (15%) 2 (17%) 4 (16%)

Types of breaks

horseshoe tear 8 (62%) 5 (42%) 13 (52%)

giant tear 1 (7%) 1 (8%) 2 (8%)

round tear 4 (31%) 4 (33%) 6 (32%)

ora dialysis 0 (0%) 2 (17%) 2 (8%)

Extent of detachment

1 quadrant 0 (0%) 0 (0%) 0 (0%)

2 quadrants 13 (65%) 5 (10%) 18 (48%)

3 quadrants 2 (10%) 6 (35%) 8 (22%)

4 quadrants (total) 5 (25%) 6 (35%) 11 (30%)

Macula On/OFF

on 6 (30%) 3 (17%) 9 (24%)

off 14 (70%) 14 (83%) 28 (76%)

Associated PVR*

yes 5 (25%) 7 (41%) 12 (32%)

no 15 (75%) 10 (59%) 25 (68%)

Previous trauma history

yes 2 (10%) 9 (53%) 11 (30%)

no 18 (90%) 8 (47%) 26 (70%)

PVR: proliferative vitreoretinopathy

(5)

al¹²reported that pseudophakic RD occurs at 20 months after cataract extraction and aphakic RD at 52 months, on average. It was reported that 58% of pseudophakic eyes and 24% of aphakic eyes had RD within 1 year after cataract extraction. The mean interval between cataract extraction and RD was significantly longer in the aphakic group (148 months on average) than in the pseudophakic group (31 months on average) in our study. The frequency with which RD occurred within 1 year was 12% in the aphakic group and 25% in the pseudophakic group. Our findings are consistent with those reported by Yoshida et al¹²and by Snyder et al.¹⁹

Aphakic patients were more inclined to have silent RD than pseudophakic patients. The pseudophakic group had some degree of VA and, if RD occurred, the patient was more likely to notice the decrease in VA. This is an advantage for pseudophakic patients and may be related with the earlier diagnosis of RD than aphakic patients.

Aphakic patients have poor VA, and therefore can- not easily recognize their decreased VA which delays the diagnosis of RD.

It is interesting that there was a relationship between the occurrence of RD and the status of posterior capsule. Hwang et al¹⁸reported that the mean time of development of RD was 21.5 months on average in eyes with intact posterior capsule and 4.1 months in eyes with ruptured posterior capsule.

Rickman et al²⁰reported that 46% of the eyes with pseudophakic RD after YAG capsulotomy occurred within 6 months. The posterior capsule had been damaged in 30% of the pseudophakic group in our

study. In 50% of cases with ruptured posterior capsule, RD occurred within 1 year. These findings are similar to previous reports.^18,20 Posterior capsule rupture leads to a break in the anterior hyaloid mem- brane, and it forms a peripheral retinal tear as trac- tional force to the vitreoretinal junction. Therefore, in cases of posterior capsule rupture during cataract extraction, whether ECCE or phacoemulsification, it is important that the patient is followed up very closely. Also, YAG capsulotomy should not be performed casually but only when necessary.

Postoperative follow-up is required especially for the first 6 months after YAG capsulotomy due to the high incidence of RD during this period.²⁰

The frequency of no breaks was significantly higher in pseudophakic RD than in phakic or aphakic RD.¹⁶The reasons are incomplete fundus view due to a small pupil, a disturbing run of anterior capsulorhexis, IOL, residual lens cortex and any posterior capsular opacification.^21-23 In our study, we could not found any retinal tears in 7 pseudophakic (35%) and 5 aphakic (29%) eyes. However, the retina was attached stably in 6 pseudophakic (96%) and 4 aphakic (80%) eyes. Therefore, the anatomical success rate of RD surgery was not influenced by the non-detection of retinal tear, consistent with the results of Ho and Tolentino¹⁷and Hwang et al.¹⁸ In aphakic RD, RD is most often related to numerous small holes as many authors have previ- ously described.^15,16In our study however, a single break was found in 72% of aphakic RD and there was no case of multiple breaks.

The location of the retinal break was in the super- Table 4. Final post-operative best corrected visual acuity

No. of eyes

Visual Pseudophakia Aphakia Total

acuity Macula-on Macula-off Macula-on Macula-off Macula-on Macula-off

< HM 0 0 0 2 (14%) 0 2 (7%)

FC 0 2 (14%) 0 1 (7%) 0 3 (11%)

0.1-0.2 0 2 (14%) 0 5 (36%) 0 7 (25%)

0.3-0.4 0 3 (22%) 1 (33%) 2 (14%) 1 (11%) 5 (18%)

> 0.5 6 (100%) 7 (50%) 2 (67%) 4 (29%) 8 (89%) 11 (39%)

Total 6 14 3 14 9 28

HM: hand movement, FC: finger count

(6)

otemporal quadrant in more than 50% of our cases.

In superotemporal breaks, early macular detachment would be possible and the patient was more likely to notice the decrease in VA, especially in pseudophakic RD.

The extent of RD was 2 quadrants in 65% of pseudophakic RD and 4 quadrants in 35% of aphakic RD. Macular detachment was more frequent in aphakic RD than pseudophakic RD (83% vs. 70%) because of the poor VA in aphakic RD. It is also related to poor final VA recovery in aphakic RD patients postoperatively.

The anatomical success rate of pseudophakic RD surgery was reported as 67~83% by Hwang et al,¹⁸ 85% by Lee and Yoon²⁴and 74~97% by Ranta and Kivela.²⁵In our study, the anatomical success rate of the primary reattachment surgery was 80% in pseudophakic RD and 65% in aphakic RD. The overall success rate of reattachment surgery was 95% in pseudophakic RD and 88% in aphakic RD.

The rate of final VA better than 20/40 was reported as 17.7% by Lee and Yoon,²⁴35% by Freeman et al,¹¹ 42% by Ho and Tolentino,¹⁷ and 31.5% by Hwang et al.¹⁸The proportion of eyes with VA better than 20/40 was 80% in the eyes without macular detachment and 14.2% in the eyes with macular detachment. In our study, the proportion of eyes with VA better than 20/40 was 65% in pseudophakic RD and 35% in aphakic RD. In cases without macular detachment, the proportion of eyes with final VA better than 20/40 was 100% in pseudophakic eyes and 67% in aphakic eyes. In cases with macular detachment, the proportion of eyes with final VA better than 20/40 was 50% in pseudophakic eyes and 29% in aphakic eyes. Aphakic RD had poorer postoperative VA than pseudophakic RD.

The reasons for this result were delayed diagnosis of RD in aphakic patients because of their poor VA, the greater frequency of macular detachment at the time of reattachment surgery and the lower success rate of primary reattachment surgery in aphakic RD.

It was reported that macular edema, cataract, macular degeneration and glaucoma were the reasons for poor VA after retinal reattachment.²⁴In our study, macular degeneration, vitreous opacity, glaucoma and bullous keratopathy were the reasons for the poor VA after retinal reattachment surgery.

In conclusion, the early detection of RD by regu-

lar fundus examination is important, because aphakic and pseudophakic RD are usually detected after they have progressed far. Especially, RD occurs earlier and more often in cases of posterior capsule rupture during cataract surgery or YAG laser capsulotomy than in other cases, and therefore regular and thorough fundus examination should be performed.

REFERENCES

1. Ah-Fat FG, Sharma MC, Majid MA, McGalliad JN, Wong D. Trends in vitreoretinal surgery at a tertiary referral centre. Br J Ophthalmol 1999:83:396-398.

2. Javitt JC, Street DA, Tielsch JM, Wang Q, Kolb MM, Schien O, Sommer A, Bergner M, Steinberg EP. National outcomes of cataract extraction. Retinal detachment and endophthalmitis after outpatient cataract surgery. Cataract Patient Outcomes Research Team. Ophthalmology 1994;101:100-105; discus- sion106.

3. Tielsch JM, Legro MW, Cassard SD, Schein OD, Javitt JC, Singer AE, Bass EB, Steinberg EP. Risk factors for retinal detachment after cataract surgery.

A population-based case-control study.

Ophthalmology 1996;103:1537-1545.

4. McHugh D, Wong D, Chignell A, Leaver P, Coolig R. Pseudophakic retinal detachment. Graefe’s Arch Clin Exp Ophthalmol. 1991;229:521-525.

5. Coonan P, Fung WE, Webster RG. The incidence of retinal detachment following extracapsular cataract extraction. Ophthalmology. 1985;92:1096-1101.

6. Davison JA. Retinal tears and detachment after extra- capsular cataract surgery. J Cataract Refract Surg.

1988;14:623-632.

7. Smith PW, Stark WJ, Maumenee E. Retinal detachment after extracapsular cataract extraction with pos- terior chamber intraocular lens. Ophthalmology.

1987;94:495-504.

8. Javitt SC, Vitale S, Canner JK. National outcomes of cataract extraction I. Retinal detachment after inpa- tient surgery. Ophthalmology. 1991;98:895-902.

9. Niels EN, Kriston N. Epidemiology of retinal detachment following extracapsular cataract examination. A follow-up study with an analysis of risk factors. J Cataract Refract Surg. 1993;19:675-680.

10. Yoshida A, Ogasawara H, Jalkh AE, Sanders RJ, McMeel JW, Schepens CL. Retinal detachment after cataract surgery. Surgical result. Ophthalmology.

1992;99;460-465.

11. Freeman HM, Dobbic JG, Fredman MW.

Pseudophakic retinal detachment. Mal Prol

(7)

Ophthalmol. 1979;20:345-353.

12. Yoshida A, Ogasawara H, Jalkh AE, Sanders RJ, McMeel JW, Schepens CL. Retinal detachment after cataract surgery. Predisposing factors.

Ophthalmology. 1992;99:453-459.

13. DY Sun, JH Lee. The incidence of retinal detachment after cataract surgery according to surgical methods.

J Korean Ophthalmol Soc. 1995;36;2157-2161.

14. Wilkinson CP. Retinal detachment following IOL implantation. Ophthalmology. 1981;88:410-413.

15. Schepens CL, Marden D. Data on the natural history of retinal detachment I. Age and sex relationships.

Arch Ophthalmol. 1961;66:631-642.

16. Ashrafzadeh MT, Schepens CL, Elzeneing II.

Aphakic and phakic retinal detachment. I. preopera- tive findings. Arch Ophthalmol. 1973;89:476-483.

17. Ho PC, Tolentino FI. Pseudophakic retinal detachment. Surgical success rate with various types of IOLs. Ophthalmology. 1984;91:847-852.

18. US Whang, JI Kim, JM Park. Clinical evaluation of pseudophakic retinal detachment. J Korean Ophthalmol Soc. 2001;42:991-996.

19. Snyder WB, Bernstein I, Fuller D. Retinal detach-

ment and pseudophakia. Ophthalmology.

1979;86:229-238.

20. Rickman-Barger L, Florine CW, Larson RS, Lindstrom RL. Retinal detachment after neodymi- um:YAG laser posterior capsulotomy. Am J Ophthalmol. 1989;107:531-536.

21. Girard P, Karponzas I. Pseudophakic retinal detach- ment: anatomic and visual results. Graefe’s Arch Clin Exp Ophthalmol. 1995;233:324-330.

22. Greven CM, Sanders RJ, Brown GC. Pseudophakic retinal detachments, Anatomic and visual results.

Ophthalmology. 1992;99:257-262.

23. Brazitikos PD, D’Amiko DJ, Tsinopoulous IT, Stanges NT. Primary vitrectomy with perfluoro-n- octane use in the treatment of pseudophakic retinal detachment with undetected retinal breaks. Retina.

1999;19:103-109.

24. MS Lee, IH Yoon. Characteristics of retinal detach- ment in pseudophakic eyes. J Korean Ophthalmol Soc. 1997;38:579-584.

25. Ranta P, Kivela T. Functional and anatomical out- come of retinal detachment surgery in pseudophakic eyes. Ophthalmology. 2002;109:1432-1440.