Postoperative inflammation after clear corneal and sclerocorneal incisions

Postoperative inflammation after clear corneal and sclerocorneal incisions Andreas Kruger, MD, Jorg Schauersberger, MD, Oliver Findl, MD, Vanessa Petternel, Gerhard Svolba, MSc, Michael Amon, MD

ABSTRACT Purpose: To compare two standard small inclsion techniques for cataract surgery- . clear corneal incision and sclerocorne~ :;if.lcision-with regard to postoperative disturbance of the blood-aqueous barrier:(aAB). ······r

Setting: Department of Ophthalmology,

Un.i~~f~iiyOf Vienna, .... ::.. .

Austria .

Methods: This prospective comparative 'stcidy: comprised 108 eyes with senile

cataract. A clear corneal tunnel incision~~$
, '! ' . ~ ' :,

,

Conclusion: Postoperative trauma, meas~ed:'oyt,he BAB disturbance, was equally : , :'.r J' t '.~ ~' ·..t ,:',: low after clear corneal and sclerocorneaJ ;ll'lqJSIOns. J Cataract Refract Surg 1998; 24:524-528

········ ·· .

T

here are many causes of inflammation and transient or permanent breakdown of the bloodaqueous barrier (BAB) after cataract surgery with intraocular lens (IOL) implantation. Intraoperative trauma, defects in IOL material or design, mechanical irritation caused by chafing of the IOL optic or haptics on adjacent tissue, infectious particles, and crystalline lens remnants are the most frequent causes.! Postoperative inflammation may lead to posterior capsule fibrosis, cystoid macular edema, or bullous keratopathy.2

Reprint requests to Andreas Kruger, MD, Vienna General Hospital, Department of Ophthalmology. University of Vienna, Wahringergiirtel 18-20, AI090 Vienna, Austria.

524

Clear corneal incisions and sclerocorneal incisions with tunnel preparation are standard cataract surgery techniques. 3 Unlike clear corneal incisions, sclerocorneal incisions involve prior opening of the conjunctiva and cauterization of the wound area. There are two further differences: (1) a bridle suture is usually placed before the sclerocorneal incision; (2) tunnel preparation and subsequent manipulation are done through the vascularized scleral tissue, not through the tissue of the avascular cornea. The Kowa FC 1000 laser flare-cell meter allows objective quantification of postoperative BAB disruption.~ In this prospective study, we used photometry under standardized conditions to compare the degree of trauma after clear corneal and sclerocorneal incisions.

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Patients and Methods One hundred eight patients who had in-patient cataract surgery were enrolled in the study. Fifty-three patients had a clear corneal incision and 55, a sclerocorneal incision. The two groups were comparable in terms of age and sex, with some difference in cataract location (left versus right eye) (Table 1). No patient had ocular disease other than senile cataract. Those taking systemic anti-inflammatory medication were excluded. All surgery was performed by an experienced surgeon (A.J.K.) after administration of peribulbar anesthesia (2.5 mL lidocaine 2% plus 2.5 mL bupivacaine 0.5%). Before the scleral incision was made, a 4-0 silk bridle suture was placed through the insertion of the superior rectus muscle. The conjunctiva was opened and the wound area cauterized. A straight, 3.2 mm long scleral incision was made 2.0 mm behind the limbus. A tunnel was prepared with a 3.2 mm bevel-up steel lance. A paracentesis was made at the 10 o'clock position. After a shallow groove of about 400 f..lI11, a threeplane clear corneal incision was made by a temporal approach using the 3.2 mm bevel-up steel lance. The paracentesis was done in the 4 or 7 o'clock position, depending on the eye (left or right). The rest of the procedure was standardized and consisted of the following steps: (1) a continuous curvilinear capsulorhexis with a bent 24 gauge cannula under sodium hyaluronate (Healon®); (2) hydro dissection and hydrodelineation with fortified balanced Table 1. Patient characteristics. Incision Group Characteristic

Clear Corneal

Sclerocorneal

Both

53

55

Mean

73.6

76.2

75.0

SO

10.5

9.9

10.2

Number of eyes

salt solution (BSS Plus®); (3) bimanual divide and conquer phacoemulsification in the capsular bag; (4) bimanual aspiration or removal of cortical lens material and capsule polishing with the irrigation/aspiration tip; (5) delineation of the capsular bag and anterior chamber with Healon; (6) injection of a one-piece, platehaptic, foldable biconvex silicone IOL (Staar model AA4203) without incision enlargement; (7) complete removal of Heal on, especially behind the IOL, followed by filling of the anterior chamber with BSS Plus; (8) no-stitch wound closure; (9) overnight ointment dressing with betamethasone 0.1 % plus neomycin 0.5% (Betnesol N®); (10) postoperative treatment with Betnesol Nand diclofenac sodium 1% (Voltaren Ophtha®) four times a day. Pupils were dilated before surgery by applying the following eye drops three times: tropicamide (Mydriaticum Agepha®), cyclopentolate 1% (Thilo®), and Voltaren Ophtha. Oral or peri bulbar steroids or drugs that cause pupillary dilation were not used. BSS Plus with 40 mg/500 mL gentamycin (Refobacin®) and adrenaline (Suprarenin®) (0.5 mLl500 mL) were applied as intraocular infusion. In the sclerocorneal incision group, the conjunctiva was closed by cauterization. On the day before surgery and on postoperative days 1,3, 7, 14,28,60, and 90, patients with un dilated pupils were examined with the Kowa Fe 1000 laser flare-cell meter. Five measurements of anterior chamber protein levels (flare) per patient and cell counts per unit of volume (0.075 mm 3) were obtained and averaged. Group mean values and standard deviations were calculated. For each time point, the two-sided Student's t-test was used to compare the two groups in terms of flare values and cell counts.

108

Results

Age (years)

Eye Left

30

20

50

Right

23

35

58

Male

16

22

38

Female

37

33

70

Sex

Re-establishment of the BAB was similar in the clear corneal and sclerocorneal groups (Figures 1 and 2). However, recovery of BAB function had not occurred by 1 month after surgery. The baseline and postoperative anterior chamber cell counts were similar in both groups (Figures 3 and 4), with recovery to nearly preoperative levels on day 7 (Table 2). The individual time curves show greater scatter in the clear corneal incision group, especially with regard

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525

INFLAMMATION AFTER CCI AND SCI RAIl! (WS)

PIAU (WS)

140

140

120

120

100

100

110

110

60

60

40

40

ZO

ZO

OL-_____________________________

OL-___________________________

38

Z8

80

90 Do\YS POS'l'OfaATMI

Figure 1. (Kruger) Single plot of flare values in the clear corneal incision group over time.

Figure 2. (Kruger) Single plot of flare values in the sclerocor-

to cell counts. There were no noticeable mean differences except for flare values 14 days postoperatively and later.

We hypothesized that implanting a foldable silicone IOL through a clear corneal tunnel would cause less BAB disturbance in the early postoperative period than implanting it through a sclerocorneal tunnel, as demonstrated by laser flare photometry. Preoperative and postoperative administration of local antiphlogistics and cortisone markedly influences the eye's reaction to surgery, which is basically caused by the release of prostaglandins. 7,8The use of sensitive and sophisticated IOL materials further reduces inflammation. 9,lo Mechanical irritation is significantly less when the IOL is implanted in the capsular bag. Complete removal of lens remnants prevents allergic response to

lens proteins (i.e., phacoanaphylactic endophthalmitis). Infection can be prevented to a great extent by perioperative disinfection of the conjunctiva. There is, however, another cause of postoperative inflammation: surgical trauma. Gills and Sandersll compared a 3.0 and a 6.0 mm incision group and reported higher flare in the large incision group 1 day and 1 week postoperatively. Similar to our findings were those of Martin and coauthors,12 who reported no significant difference in mean flare and cell between a small incision and a 6.0 mm incision group. In contrast to our technique, they used a corneoscleral incision and silicone IOLs in the 3.0 mm group and poly(methyl methacrylate) IOLs in the 6.0 mm group. Diestelhorst and coauthors,13 implanting a three-piece silicone IOL with polyimide hap tics, did not find a difference in BAB disruption after 3.0 and 6.0 mm corneoscleral incisions. To minimize the effect of such factors as IOL design and materials, we implanted foldable plate-

CI!LL (WS)

CI!LL (WS)

Discussion

70

80

80

50

50

40

40

30

30

ZO

ZO

10

10 0

U 7 14

0

0 Z8

60

90 Do\YS POSTOPIIA'l1VII

Figure 3. (Kruger) Single plot of cell counts in the clear corneal incision group over time. 526

neal incision group over time.

.137 14

Z8

80

90

Figure 4. (Kruger) Single plot of cell counts in the sclerocorneal incision group over time.

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Table 2.

Flare and cell values over time.

PostoP.Dey$ Value

Preop

1

3

7

14

c

28 .

60

90

Flare Clear corneal incision Mean

7.7

22.5

20.3

13.9

14.2

12.6

12.7

16.2

Median

6.6

19.2

15.1

11 .1

10.8

11.4

11 .0

10.5

SO

4.7

15.6

19.0

9.0

10.2

8.4

8.8

16.2

n*

49.0

46.0

48.0

47.0

45.0

42.0

21.0

11.0

Mean

8.0

25.1

17.1

12.5

10.6

9.9

8.7

9.4

Median

7.5

15.2

14.2

11.7

9.6

9.5

7.9

9.6

Sclerocorneal incision

SO

3.3

26.6

11.5

5.6

5.0

4.0

3.9

3.7

n*

53.0

50.0

54.0

49.0

48.0

47.0

38.0

23.0

P-value t

0.71

0.56

0.32

0.35

0.04

0.07

0.06

0.20

12.2

8.6

3.5

2.8

1.0

0.7

0.9

2.0

1.3

0.7

0.7

0.4

Cell Clear corneal incision 1.7

Mean Median

0.0

8.3

4.8

SO

4.4

13.3

9.7

6.6

7.5

1.1

0.5

1.1

n*

49.0

46.0

48.0

47.0

45.0

42 .0

21.0

11.0

Mean

0.8

16.5

8.0

1.8

0.9

0.7

0.6

0.6

Median

0.1

11.2

3.5

1.0

0.7

0.4

0.2

0.3

Sclerocorneal incision

SO

2.1

17.1

11.3

2.1

1.0

0.8

0.8

0.7

n*

53.0

50.0

54.0

49.0

48.0

47.0

38.0

23.0

P-valuet *Of eyes tTwo-sided

0.21

0.17

t-test between groups at each measurement (a

0.76

0.09

0.10

0.21

0.44

0.36

= .05)

haptic silicone 10Ls and used a standardized preoperative and postoperative protocol for both groups. According to Pande and coauthors l4 and Alia and coauthors,15 early BAB disruption is mainly caused by intraoperative trauma. We observed the highest Rare and cell values on the first postoperative day and a gradual decline at subsequent follow-ups in both groups, which agrees with findings of other studies of BAB disruption after 10L implantation. 16.17 In a study using the laser Rare-cell meter, Shah and Spalton l6 described two variations in the normal pattern of postoperative BAB after manual nuclear expression. They found that recovery was uneventful in one group while the second group had a partly symptomatic increase in Rare values

between 2 and 7 days postoperatively. We did not see such an increase in a subgroup, perhaps because we did not perform manual nuclear expression. Considering that intraoperative trauma is reflected primarily in early BAB disruption, we found no difference between the two sutgical techniques. Thus, we conclude that both clear corneal and sclerocorneal incisions cause minimal trauma. Clear corneal incisions may provide more rapid visual rehabilitation and stab ility of refractive results. It seems to be a less invasive technique as no vascular cuts are made. On the other hand, the sclerocorneal incision may be "safer" lfi certain cases, for example when the incision must be enlarged. However, our results show that degree of

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INFLAMMATION AFTER CCI AND SCI

postoperative inflammation is not a valid criterion for choosing one technique over another.

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9. Amon M, Menapace R, Radax U, Freyler H. In vivo study of cell reactions on poly(methyl methacrylate) intraocular lenses with different surface properties. J Cataract Refract Surg 1996; 22:825-829 10. Lai Y-K, Fan RFT. Effect of heparin-surface-modified poly(methyl methacrylate) intraocular lenses on the postoperative inflammation in an Asian population. J Cataract Refract Surg 1996; 22:830-834 11. Gills JP, Sanders DR. Use of small incisions to control induced astigmatism and inflammation following cataract surgery. J Cataract Refract Surg 1991; 17:740-744 12. Martin RG, Sanders DR, Van der Karr MA, DeLuca M. Effect of small incision intraocular lens surgery on postoperative inflammation and astigmatism; a study of the AMO SI-18NB small incision lens. J Cataract Refract Surg 1992; 18:51-57 13. Oiestelhorst M, Oinslage S, Konen W, Krieglstein GK. Effect of 3.0 mm tunnel and 6.0 mm corneoscleral incisions on the blood-aqueous barrier. J Cataract Refract Surg 1996; 22:1465-1470 14. Pande MY, Spalton OJ, Kerr-Muir MG, Marshall J. Postoperative inflammatory response to phacoemulsification and extracapsular cataract surgery: aqueous flare and cells. J Cataract Refract Surg 1996; 22:770-774 15. Ali6 JL, Sayans JA, Chipont E. Laser flare-cell measurement of inflammation after uneventful extracapsular cataract extraction and intraocular lens implantation. J Cataract Refract Surg 1996; 22:775-779 16. Shah SM, Spalton OJ. Changes in anterior chamber flare and cells following cataract surgery. Br J Ophthalmol 1994; 78:91-94 17. Sanders DR, Spigelman A, Kraff C, et al. Quantitative assessment of postsurgical breakdown of the bloodaqueous barrier. Arch Ophthalmol1983; 101:131-133

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