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Subconjunctival antibiotics for acute postcataract extraction endophthalmitis—is it necessary?
Subconjunctival Antibiotics for Acute Postcataract Extraction Endophthalmitis—Is It Necessary?
vancomycin and cefazolin, at the discretion of the surgeon. Rates of light perception vision at presentation and of vitrectomy differed between the two groups. To account for these differences, based on results from the Endophthalmitis Vitrectomy Study (EVS) in which vitrectomy was of no benefit for patients with hand motions or better vision,1 we included only patients presenting with hand motions or better vision (25 SC⫹ and 18 SC⫺). Statistical analyses included 2 or Fischer t test, and a linear regression model controlling for initial visual acuity, with P ⬍ .05 considered statistically significant. The two groups were similar at baseline (Table 1). No statistically significant difference in presenting and final visual acuity or in the visual outcome as measured by the change of logMAR could be shown between the two groups (Table 2). In the SC⫹ group compared with SC⫺ group, the rate of obtaining final visual acuity of 20/40 or better was 60% versus 72% (P ⫽ .69), which compared well with the an equivalent rate of 64% in the EVS,1 and that of obtaining 20/200 or better was 96% versus 94% (P ⫽ .99). The mean change in logMAR (improvement) was –1.36 (⫾ 0.74 SD) for the SC⫹ group versus –1.34 (⫾ 0.99 SD) for the SC⫺ group (P ⫽ .93, t test). In the linear regression model controlling for initial visual acuity, there was no statistically significant difference in the mean logMAR change between the SC⫺ and SC⫹ groups (P ⫽ .73; 95% confidence interval ⫽ ⫺0.26 –⫹0.37).2 Before the acceptance of intravitreal antibiotic injection, treatment of postoperative endophthalmitis historically involved delivery of antibiotics to the eye via as many other routes as possible. Because of the seriousness of endophthalmitis, such approaches remained part of standard clinical practice until shown to be of dubious benefit as in the EVS. Poor vitreal penetration of subconjunctival antibiotics as noted in pharmacologic studies3–5 would explain the absence of detectable treatment effect with subconjunctival antibiotics in our study. Limitations of this study include its retrospective nature, inclusion of only patients with hand motions or better presenting vision, and small sample sizes, although the trend in visual outcome was similar to that seen in the larger EVS. In conclusion, subconjunctival antibiotic injection as an adjunct to intravitreal antibiotics was unassociated with treatment benefit for patients with acute postoperative endophthalmitis presenting with hand motions or better vision. Elimination of routine use of subconjunctival antibiotics in such cases would reduce the risk of medication mixing error, such as inadvertent intraocular injection of antibiotics intended for a subconjunctival site, intraocular perforation, conjunctival irritation or necrosis, and patient discomfort. Because of the nonrandomized nature of this study, however, clinical experience should remain the basis on which such treatment is considered.
Mohan N. Iyer, MD, Dennis P. Han, MD, Hyun J. Yun, PhD, Dan Eastwood, MS, Judy E. Kim, MD, Thomas B. Connor, MD, William J. Wirostko, MD, and Sundeep Dev, MD To evaluate the efficacy of adjunctive subconjunctival antibiotic injection in the treatment of acute postcataract extraction endophthalmitis. DESIGN: Retrospective cohort study. METHODS: Patients who presented with hand motions or better vision and received subconjunctival antibiotics (SCⴙ group) were compared with those who did not (SCⴚ group) in the treatment of acute postoperative endophthalmitis. RESULTS: The rate of obtaining a final vision of 20/40 or better was 60% in the SCⴙ group (n ⴝ 25) compared with 72% in the SCⴚ group (n ⴝ 18) (P ⴝ .69), and the mean change in logMAR was –1.36 (improvement) versus –1.34 (P ⴝ .93). Based on a linear regression model controlling for presenting vision, there was no statistical difference in the mean logMAR change between the two groups (P ⴝ .73). CONCLUSION: Subconjunctival antibiotic injection as an adjunct to intravitreal antibiotics was unassociated with treatment benefit in patients with acute postoperative endophthalmitis presenting with vision of hand motions or better. (Am J Ophthalmol 2004;137:1120 –1121. © 2004 by Elsevier Inc. All rights reserved.) PURPOSE:
T
HE INJECTION OF INTRAVITREAL ANTIBIOTICS FOLLOW-
ing vitreous biopsy or vitrectomy is the mainstay for management of postoperative endophthalmitis, and the routine use of adjunctive subconjunctival antibiotics remains controversial. We compared patients who received adjunctive subconjunctival antibiotics (SC⫹) with those who did not (SC⫺) for acute postcataract extraction endophthalmitis between 1991 and 2002. Subconjunctival antibiotics consisted of vancomycin, cefazolin, vancomycin and ceftazidime, vancomycin and gentamycin, or Accepted for publication Dec 15, 2003. From the Departments of Ophthalmology (M.N.I., D.P.H., J.E.K., T.B.C., W.J.W.) and Biostastistics (H.J.Y., D.E.), Medical College of Wisconsin, Milwaukee, Wisconsin; and Department of Vitreoretinal Surgery, P.A. (S.D.), Minneapolis, Minneapolis. Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York, and by the Thomas M. Aaberg Retina Research Fund, Milwaukee, Wisconsin. Presented in part as a poster at the 2003 Association for Research in Vision and Ophthalmology meeting and at the 2003 meeting of the Retina Society. Inquires to: Dennis P. Han, MD, Department of Ophthalmology, Medical College of Wisconsin, 925, N. 87th Street, Milwaukee, WI 53226; e-mail: [email protected]
1120
AMERICAN JOURNAL
OF
OPHTHALMOLOGY
JUNE 2004
TABLE 1. Baseline Characteristics
Mean patient age (yr) Mean duration from CE (d) to intravitreal antibiotics Mean follow-up duration (d) Cultures Negative culture Coagulase–negative staphylococcus Other gram-positive organisms Unknown Rate of vitrectomy PPV TAP
SC⫹, % (⫾ SD) (n ⫽ 25)
SC⫺, % (⫾ SD) (n ⫽ 18)
73 (⫾ 11) 12 (⫾ 10) 103 (⫾ 78)
72 (⫾ 9) (P ⫽ .76; t test) 9 (⫾ 8) (P ⫽ .34; t test) 72 (⫾ 40) (P ⫽ .12; t test) (P ⫽ .82; Fischer exact) 4 (22) 10 (56) 4 (22) 0 (0) (P ⫽ .09; Fischer exact) 2 (11) 16 (89)
6 (24) 12 (48) 5 (20) 2 (8) 9 (36) 16 (64)
CE ⫽ cataract extraction with intraocular lens placement; PPV ⫽ pars plana vitrectomy; SC⫹ ⫽ patients receiving subconjunctival antibiotics; SC⫺ ⫽ patients not receiving subconjunctival antibiotics; TAP ⫽ vitreous biopsy.
TABLE 2. Comparison of Initial and Final Visual Acuity and Visual Outcomes for Patients Presenting With Acute Postoperative Endophthalmitis With Presenting Vision of Hand Motions or Better SC⫹, ⫾ SD (%) (n ⫽ 25)
Initial VA (P ⫽ .46, Fischer exact) ⬍5/200 ⬍20/200–5/200 20/50–20/200 ⬎20/50 Final VA (P ⫽ .43, Fischer exact) ⬍5/200 ⬍20/200–5/200 20/50–20/200 ⬎20/50 Mean initial logMAR Mean final logMAR Change in mean logMAR Change in logMAR (P ⫽ .49; Fischer exact) ⬎⫺0.5 ⱕ⫺0.5 to ⬎⫺1.0 ⱕ⫺1.0 to ⬎⫺1.5 ⱕ⫺1.5
13 (52) 6 (24) 5 (20) 1 (4)
SC⫺, ⫾ SD (%) (n ⫽ 18)
11 (61) 1 (6) 5 (28) 1 (6)
0 (0) 1 (4) 9 (36) 15 (60) 1.71 (⫾ 0.73) 0.35 (⫾ 0.36) ⫺1.36 (⫾ 0.74)
1 (5.6) 0 (0) 4 (22) 13 (72) 1.75 (⫾ 0.89) (P ⫽ .88; t test) 0.41 (⫾ 0.68) (P ⫽ .70; t test) ⫺1.34 (⫾ 0.99) (P ⫽ .93; t test)
4 (16) 4 (16) 5 (20) 12 (48)
5 (27.8) 2 (11.1) 1 (5.6) 10 (55.6)
Change in logMAR ⫽ postoperative minus preoperative logMAR; logMAR ⫽ logarithm of mean angle of resolution; SC⫹ ⫽ patients receiving subconjunctival antibiotics; SC⫺ ⫽ patients not receiving subconjunctival antibiotics; VA ⫽ visual acuity.
REFERENCES
1. Endophthalmitis Vitrectomy Study Group. Results of the Endophthalmitis Vitrectomy Study. A randomized trial of immediate vitrectomy and of intravenous antibiotics for the treatment of postoperative bacterial endophthalmitis. Arch Ophthalmol 1995;113:1479 –1496. 2. SAS Software: usage and reference, Version 8. Cary, NC: SAS Institute, 1997.
VOL. 137, NO. 6
3. Barza M. Antibacterial agents in the treatment of ocular infections. Infec Dis Clin North Amer 1989;3:533–551. 4. Barza M, Lynch E, Baum JL. Pharmacokinetics of newer cephalosporins after subconjunctival and intravitreal injection in rabbits. Arch Ophthalmol 1993;111:121–125. 5. Barza M, Doft B, Lynch E. Ocular penetration of ceftriaxone, ceftazidime, and vancomycin after subconjunctival injection in humans. Arch Ophthalmol 1993;111:492–494.
BRIEF REPORTS
1121
vancomycin and cefazolin, at the discretion of the surgeon. Rates of light perception vision at presentation and of vitrectomy differed between the two groups. To account for these differences, based on results from the Endophthalmitis Vitrectomy Study (EVS) in which vitrectomy was of no benefit for patients with hand motions or better vision,1 we included only patients presenting with hand motions or better vision (25 SC⫹ and 18 SC⫺). Statistical analyses included 2 or Fischer t test, and a linear regression model controlling for initial visual acuity, with P ⬍ .05 considered statistically significant. The two groups were similar at baseline (Table 1). No statistically significant difference in presenting and final visual acuity or in the visual outcome as measured by the change of logMAR could be shown between the two groups (Table 2). In the SC⫹ group compared with SC⫺ group, the rate of obtaining final visual acuity of 20/40 or better was 60% versus 72% (P ⫽ .69), which compared well with the an equivalent rate of 64% in the EVS,1 and that of obtaining 20/200 or better was 96% versus 94% (P ⫽ .99). The mean change in logMAR (improvement) was –1.36 (⫾ 0.74 SD) for the SC⫹ group versus –1.34 (⫾ 0.99 SD) for the SC⫺ group (P ⫽ .93, t test). In the linear regression model controlling for initial visual acuity, there was no statistically significant difference in the mean logMAR change between the SC⫺ and SC⫹ groups (P ⫽ .73; 95% confidence interval ⫽ ⫺0.26 –⫹0.37).2 Before the acceptance of intravitreal antibiotic injection, treatment of postoperative endophthalmitis historically involved delivery of antibiotics to the eye via as many other routes as possible. Because of the seriousness of endophthalmitis, such approaches remained part of standard clinical practice until shown to be of dubious benefit as in the EVS. Poor vitreal penetration of subconjunctival antibiotics as noted in pharmacologic studies3–5 would explain the absence of detectable treatment effect with subconjunctival antibiotics in our study. Limitations of this study include its retrospective nature, inclusion of only patients with hand motions or better presenting vision, and small sample sizes, although the trend in visual outcome was similar to that seen in the larger EVS. In conclusion, subconjunctival antibiotic injection as an adjunct to intravitreal antibiotics was unassociated with treatment benefit for patients with acute postoperative endophthalmitis presenting with hand motions or better vision. Elimination of routine use of subconjunctival antibiotics in such cases would reduce the risk of medication mixing error, such as inadvertent intraocular injection of antibiotics intended for a subconjunctival site, intraocular perforation, conjunctival irritation or necrosis, and patient discomfort. Because of the nonrandomized nature of this study, however, clinical experience should remain the basis on which such treatment is considered.
Mohan N. Iyer, MD, Dennis P. Han, MD, Hyun J. Yun, PhD, Dan Eastwood, MS, Judy E. Kim, MD, Thomas B. Connor, MD, William J. Wirostko, MD, and Sundeep Dev, MD To evaluate the efficacy of adjunctive subconjunctival antibiotic injection in the treatment of acute postcataract extraction endophthalmitis. DESIGN: Retrospective cohort study. METHODS: Patients who presented with hand motions or better vision and received subconjunctival antibiotics (SCⴙ group) were compared with those who did not (SCⴚ group) in the treatment of acute postoperative endophthalmitis. RESULTS: The rate of obtaining a final vision of 20/40 or better was 60% in the SCⴙ group (n ⴝ 25) compared with 72% in the SCⴚ group (n ⴝ 18) (P ⴝ .69), and the mean change in logMAR was –1.36 (improvement) versus –1.34 (P ⴝ .93). Based on a linear regression model controlling for presenting vision, there was no statistical difference in the mean logMAR change between the two groups (P ⴝ .73). CONCLUSION: Subconjunctival antibiotic injection as an adjunct to intravitreal antibiotics was unassociated with treatment benefit in patients with acute postoperative endophthalmitis presenting with vision of hand motions or better. (Am J Ophthalmol 2004;137:1120 –1121. © 2004 by Elsevier Inc. All rights reserved.) PURPOSE:
T
HE INJECTION OF INTRAVITREAL ANTIBIOTICS FOLLOW-
ing vitreous biopsy or vitrectomy is the mainstay for management of postoperative endophthalmitis, and the routine use of adjunctive subconjunctival antibiotics remains controversial. We compared patients who received adjunctive subconjunctival antibiotics (SC⫹) with those who did not (SC⫺) for acute postcataract extraction endophthalmitis between 1991 and 2002. Subconjunctival antibiotics consisted of vancomycin, cefazolin, vancomycin and ceftazidime, vancomycin and gentamycin, or Accepted for publication Dec 15, 2003. From the Departments of Ophthalmology (M.N.I., D.P.H., J.E.K., T.B.C., W.J.W.) and Biostastistics (H.J.Y., D.E.), Medical College of Wisconsin, Milwaukee, Wisconsin; and Department of Vitreoretinal Surgery, P.A. (S.D.), Minneapolis, Minneapolis. Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York, and by the Thomas M. Aaberg Retina Research Fund, Milwaukee, Wisconsin. Presented in part as a poster at the 2003 Association for Research in Vision and Ophthalmology meeting and at the 2003 meeting of the Retina Society. Inquires to: Dennis P. Han, MD, Department of Ophthalmology, Medical College of Wisconsin, 925, N. 87th Street, Milwaukee, WI 53226; e-mail: [email protected]
1120
AMERICAN JOURNAL
OF
OPHTHALMOLOGY
JUNE 2004
TABLE 1. Baseline Characteristics
Mean patient age (yr) Mean duration from CE (d) to intravitreal antibiotics Mean follow-up duration (d) Cultures Negative culture Coagulase–negative staphylococcus Other gram-positive organisms Unknown Rate of vitrectomy PPV TAP
SC⫹, % (⫾ SD) (n ⫽ 25)
SC⫺, % (⫾ SD) (n ⫽ 18)
73 (⫾ 11) 12 (⫾ 10) 103 (⫾ 78)
72 (⫾ 9) (P ⫽ .76; t test) 9 (⫾ 8) (P ⫽ .34; t test) 72 (⫾ 40) (P ⫽ .12; t test) (P ⫽ .82; Fischer exact) 4 (22) 10 (56) 4 (22) 0 (0) (P ⫽ .09; Fischer exact) 2 (11) 16 (89)
6 (24) 12 (48) 5 (20) 2 (8) 9 (36) 16 (64)
CE ⫽ cataract extraction with intraocular lens placement; PPV ⫽ pars plana vitrectomy; SC⫹ ⫽ patients receiving subconjunctival antibiotics; SC⫺ ⫽ patients not receiving subconjunctival antibiotics; TAP ⫽ vitreous biopsy.
TABLE 2. Comparison of Initial and Final Visual Acuity and Visual Outcomes for Patients Presenting With Acute Postoperative Endophthalmitis With Presenting Vision of Hand Motions or Better SC⫹, ⫾ SD (%) (n ⫽ 25)
Initial VA (P ⫽ .46, Fischer exact) ⬍5/200 ⬍20/200–5/200 20/50–20/200 ⬎20/50 Final VA (P ⫽ .43, Fischer exact) ⬍5/200 ⬍20/200–5/200 20/50–20/200 ⬎20/50 Mean initial logMAR Mean final logMAR Change in mean logMAR Change in logMAR (P ⫽ .49; Fischer exact) ⬎⫺0.5 ⱕ⫺0.5 to ⬎⫺1.0 ⱕ⫺1.0 to ⬎⫺1.5 ⱕ⫺1.5
13 (52) 6 (24) 5 (20) 1 (4)
SC⫺, ⫾ SD (%) (n ⫽ 18)
11 (61) 1 (6) 5 (28) 1 (6)
0 (0) 1 (4) 9 (36) 15 (60) 1.71 (⫾ 0.73) 0.35 (⫾ 0.36) ⫺1.36 (⫾ 0.74)
1 (5.6) 0 (0) 4 (22) 13 (72) 1.75 (⫾ 0.89) (P ⫽ .88; t test) 0.41 (⫾ 0.68) (P ⫽ .70; t test) ⫺1.34 (⫾ 0.99) (P ⫽ .93; t test)
4 (16) 4 (16) 5 (20) 12 (48)
5 (27.8) 2 (11.1) 1 (5.6) 10 (55.6)
Change in logMAR ⫽ postoperative minus preoperative logMAR; logMAR ⫽ logarithm of mean angle of resolution; SC⫹ ⫽ patients receiving subconjunctival antibiotics; SC⫺ ⫽ patients not receiving subconjunctival antibiotics; VA ⫽ visual acuity.
REFERENCES
1. Endophthalmitis Vitrectomy Study Group. Results of the Endophthalmitis Vitrectomy Study. A randomized trial of immediate vitrectomy and of intravenous antibiotics for the treatment of postoperative bacterial endophthalmitis. Arch Ophthalmol 1995;113:1479 –1496. 2. SAS Software: usage and reference, Version 8. Cary, NC: SAS Institute, 1997.
VOL. 137, NO. 6
3. Barza M. Antibacterial agents in the treatment of ocular infections. Infec Dis Clin North Amer 1989;3:533–551. 4. Barza M, Lynch E, Baum JL. Pharmacokinetics of newer cephalosporins after subconjunctival and intravitreal injection in rabbits. Arch Ophthalmol 1993;111:121–125. 5. Barza M, Doft B, Lynch E. Ocular penetration of ceftriaxone, ceftazidime, and vancomycin after subconjunctival injection in humans. Arch Ophthalmol 1993;111:492–494.
BRIEF REPORTS
1121