Corneal infection after radial keratotomy

Corneal infection after radial keratotomy

Corneal infection after radial keratotomy Anita Panda, MD, Gopal K. Das, MD, Murgeshan Vanathi, MBBS, Abhisan Kumar ABSTRACT Purpose: To evaluate nin...

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Corneal infection after radial keratotomy Anita Panda, MD, Gopal K. Das, MD, Murgeshan Vanathi, MBBS, Abhisan Kumar

ABSTRACT Purpose: To evaluate nine eyes that developed corneal infection after radial keratotomy (RK) and their subsequent management.

Setting: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India. Method: The parameters evaluated were interval between RK and development of the ulcer, number of keratotomy incisions, nature of surgery (primary or secondary), status at presentation, and best corrected visual acuity (BCVA). Corneal scrapings were taken from all eyes for microbiological evaluation. Initial therapy was based on clinical impression and subsequent therapy, on the microbiological report.

Results: Staphylococcus species were the most frequently isolated bacteria followed by Pseudomonas aeruginosa. Two eyes had fungal growth, and no organisms were isolated from one. All but one eye responded to medical therapy; healing took 23 to 26 days. Therapeutic penetrating keratoplasty (PKP) was done in one eye. Presenting BCVA of hand movement to 6/36 improved to hand movement to 6/18 after the ulcer healed. Final BCVA was 6{36 to 6/9 after lamellar keratoplasty or PKP or with contact lens or spectacle correction.

Conclusion: Our study shows that corneal infection is a potential complication of RK. Therefore, persistent postoperative irritation should be carefully observed to ensure early diagnosis and prompt therapy. J Cataract Refract Burg 1998; 24: 331-334

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otential complications of radial keratotomy (RK) include hyphema, induced astigmatism, undercorrection or overcorrection, cataract, glare, incisional vascularization, inclusion cyst, recurrent epithelial erosion, endothelial cell loss, and anterior chamber and globe perforation. l -4 Corneal and intraocular infections have also been reported. 5- 7 We report on nine eyes with corneal infection after RK and their management in a tertiary care hospital. From Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute ofMedical Sciences, New Delhi, India. Reprint requests to Anita Panda, MD, Additional Professor, 404, Hawa Singh Block, Asiad Village, New Delhi-I I 0049, India.

Patients and Methods This study comprised nine patients who had RK at another center and presented with corneal ulcer to the cornea service of Dr. Rajendra Prasad Centre for Ophthalmic Sciences between 1987 and 1996. Patient age ranged from 15 to 29 years. There were five men and four women. Parameters evaluated were the site of ulcer, number of keratotomy incisions, nature of surgery (primary or secondary), duration of topical drug use, laboratory analysis of specimens, therapy, time to healing, visual acuity, subsequent surgery, and final outcome. All patients had a corneal scraping from ulcer sites for bacterial and fungal staining and for culture sensi-

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CORNEAL INFECTION AFTER RK

tlVlty tests. Based on clinical impression, all patients initially received tobramycin sulfate 1.3% and cefazolin sodium 5% eyedrops at 1 hour intervals along with a cycloplegic. When there was strong clinical suspicion of fungal keratitis along with positive potassium hydroxide staining for fungi, natamycin eyedrops were given every hour during the day and every 2 hours at night. Subsequent therapy was changed based on culturesensitivity reports.

Results The ulcer site was central in four eyes and midperipheral in four (Table 1). One eye had an extensive ulcer involving the central, midperipheral, and peripheral cornea. The number of incisions was from 8 to 22. Primary surgery was done in four eyes; enhancements to deepen the incisions or to make additional incisions were done in five. All patients were using topical dexamethasone with varying frequency. Cases 1 to 7 were also using gentamicin every 4 hours; Cases 8 and 9 were using it as required. Staphylococcus aureus was isolated from three eyes, Pseudomonas aeruginosa from two eyes, and Staphylococcus albus, Aspergillus, and Fusarium from one eye each. In one eye, no organisms were isolated. Eight eyes responded well to medical therapy, with healing taking from 20 to 26 days. One eye in which the ulcer progressed despite maximal

medical therapy had a therapeutic penetrating keratoplasty (PKP); the eye was saved. Best corrected visual acuity (BCVA) during the infection ranged from hand movement to 6/36 and after the ulcers healed, from hand movement to 6/18 (Table 1). Subsequently, PKP and lamellar keratoplasty were performed in four eyes for residual corneal opacity that obscured vision. One eye having PKP also had extracapsular cataract extraction and intraocular lens implantation after developing cataract as a complication of the post-RK ulcer. Final BCVA in these four eyes was 6/18 or better (Table O. The eye having therapeutic PKP had an acuity of 6/36. Three eyes did not require keratoplasty as the corneal opacity did not obscure vision. However, the quality of vision was not as expected after uneventful RK. Visual acuity in these eyes was 6/18, which improved to 6/12 with contact lens or spectacle correction.

Discussion Although rare, corneal infection related to RK is a serious complication. 8•9 Moreover, corneal infection in a seeing eye can be devastating. Development of an ulcer after RK can be caused by many factors such as preexisting pathogens in the conjunctival sac, intraoperative introduction of an organism, improper postopera-

Table 1. Patient characteristics.

caae

Age/Sex 22/F

llrne Between RK & K8I'atltls 8 weeks

RK Incision Site

Number of Inclslone

S~

MP

12

PR

2

29/M

17 days

C

12

R

3

15/M

18 days

C

12

R

4

21/F

3 days

C/MP/P

22

R

5

22/F

10 weeks

MP

12

PR

6

19/M

12 weeks

C

8

PR

7

28/M

10 weeks

MP

8

PR

8

43/M

13 months

MP

18

R

9

36/F

18 months

C

8

R

MP = midperiphery; C = center; P = periphery; PR = primary; R = repeat; Med = medication; PKP = penetrating keratoplasty; HM = hand movement; CF = finger counting; ECCE = extracapsular cataract extraction with lens implantation *Therapeutic PKP

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CORNEAL INFECTION AFTER RK

tive care, and the presence of a pathologic corneal condition such as multiple incision marks with varying depth. The use of concomitant corticosteroid eyedrops is an additional risk factor. 1o Our nine patients with RK-related corneal infection had a preponderance of gram-positive bacteria such as Staphylococcus species isolated from the eye with the ulcer. Widespread antibiotic use may contribute to an increased incidence of beta-lactamase- and cephalosporinase-producing Staphylococcus epidermis. The corneal ulcer in three eyes in our series appeared during the early postoperative period, suggesting intraoperative contamination from inadequate sterile technique or suboptimal postoperative care by the patient. As the normal cornea is resistant to infection, the ulcer in these three eyes could be explained by the invasion of a virulent organism. In two of these patients the ulcer was caused by P. aeruginosa corneal ulcer and in the third, by S. au reus. We postulate that the development of punctuate epithelial erosions and a non healing radial cut, combined with the incorrect use of topical drugs, were the important predisposing factors for the post-RK ulcers. The absence of endophthalmitis in our series indicates that no microperforation or macroperforation occurred during RK as they are significant causes of endophthalmitis in such eyes. 5 As our hospital is a tertiary eyecare center, patients

with complications are referred to us. Therefore, it was not possible in this study to evaluate the exact incidence of infection after RK. The development of an ulcer between 2 to 3 months after RK in four eyes in our series indicates improper postoperative care and prolonged topical corticosteroid use in nonhealing radial cuts. Although the risk/benefit ratio is still unknown, our study suggests that corneal infection is a potential complication of RK that should be considered by both surgeons and patients. However, careful postoperative evaluation and strict observation of persistent irritative symptoms will enable early diagnosis of corneal infection. Delayed diagnosis and inadequate therapy may lead to loss of the eye through corneal destruction. Management of ulcers following RK is no different from that of other types of corneal ulcers. Initial therapy with antimicrobial medication led to healing of the ulcer in more than 88.8% of eyes in our series. Therapeutic PKP after refractive procedures can prevent loss of the eye, as in one eye in our series. Further, PKP at a later date in such eyes can restore the initial vision and thus help in proper rehabilitation. In summary, prompt, adequate therapy will help the ulcer heal quickly. In cases in which it does not, therapeutic PKP should be considered to restore the eye's anatomical integrity. Subsequently, repeat PKP can be done to restore the pre-existing vision.

Table 1. Continued. Visual Acuity Organism Isolated

Therapy

Healing (Days)

Before Healing

After Healing

Final

Subsequent Surgery

S. aureus

Med

24

1/60

3/60

6/12

LK

S. aureus

PKP*

20

HM

HM

6/36

P aeruginosa

Med

26

HM

CF

6/12

PKP

P aeruginosa

Med

24

1/60

3/36

6/18

PKP

S. aureus

Med

24

6/60

6/18

6/18

S. a/bus

Med

26

3/60

6/24

6/18

Med

23

6/36

6/18

6/18

Med

26

HM

HM

6/9

PKP/ECCE

23

HM

HM

6/12

PKP

Fusarium Aspergillus

Med

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References l. Rowsey lJ, Balyeat HD. Radial keratotomy: preliminary re-

port on complications. Ophthalmic Surg 1982; 13:27-35 2. Gelender H, Gelber EC. Cataract following radial keratotomy. Arch Ophthalmol1983; 101:1229-1231 3. Baldone JA, Franklin RM. Cataract following radial keratotomy. Ann Ophthalmol 1983; 15:416-418 4. Girard LJ, Rodriguez J, Nino N, Wesson M. Delayed wound healing after radial keratotomy. Am J Ophthalmol 1985; 99:485-486 5. Gelender HG, Flynn HW Jr, Mandelbaum SH. Bacterial endophthalmitis resulting from radial keratotomy. Am J Ophthalmol 1982; 93:323-326

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6. Wilhelm us KR, Hamburg S. Bacterial keratitis following radial keratotomy. Cornea 1983; 2:143-146 7. Santos CRI. Herpetic corneal ulcer following radial keratotomy. Ann Ophthalmol 1983; 15:82-85 8. Duffey RJ. Bilateral Serratia marcescens keratitis after simultaneous bilateral radial keratotomy. Am J Ophthalmol 1995; 119:233-236 Matoba AY, Torres J, Wilhelmus KR, et al. Bacterial 9. keratitis after radial keratotomy. Ophthalmology 1989; 96:1171-1175 10. Gussler JR, Miller D, Jaffe M, Alfonso EC. Infection after radial keratotomy. Am J Ophthalmol 1995; 119:798-799

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