Paradox of Corneal CXL and Infectious Keratitis: To Do or Not to Do?

None of the authors have any fi nancial disclosure to make

Vishal Vohra,MS (Presenting Author), Rohit Shetty, DNB, FRCS; Harsha Nagaraj, MS; Luci Kaweri, MD; Chetna

Sharma, MS; Natasha K. Pahuja, DOMS

Narayana Nethralaya, Bangalore, INDIA

PURPOSETo evaluate the dual role of crosslinking both as a treatment modality and a pathogenic factor for microbial keratitis

Group 1 To evaluate the efficacy and safety of corneal collagen cross-linking (CXL) in infectious keratitis

Group 2To analyse the profile of microbial keratitis occurring after CXL

Riboflavin + UV A radiation

Irreversible breaks in DNA / RNA strands

Increases the corneal thermal shrinkage temperature

Effect on leucocytes

Effect on immune response

KXL in infectious keratitis: Mechanism

Kills microbes

Arrests stromal melting Reduces pain and

inflammation

Reactive Oxygen species

Non-healing microbial keratitis

Phase 1 of study Conventional CXL

15 eyes of 15 patients

Phase 2 of study (ongoing) Accelerated CXL

3 eyes of 3 patients

Not responding to 2 weeks of topical therapy

Prospective, interventional ongoing study

METHODOLOGY – GROUP1

Soak period0.1% Riboflavin

drops (Medio-Cross D) every 2 minutes for 30 minutes

Accelerated CXL in 3 patients 9mW/cm2 for 10

min

PROCEDURE

Conventional CXL – 15 patients 3mW/cm2 for 30

minutes

Riboflavin + UV-A (365nm)Irradiation

RESULTSTotal resolution: Seen in 18 patients

8 out of 11 bacterial keratitis (72.73%) showed resolution

3 out of 6 fungal keratitis (50%) showed resolution

Acanthoemeba keratitis: Favourable result but

recurrence noted Can repeat CXL be

effective???

Superficial and anterior stromal infiltrates- better response

1st POD- significantly reduced/ no pain in all patients ‘Chemical denervation’

Mean time for epithelial healing- 23 days Mean time for resolution of corneal infiltrate was 33 days

Not every story has a Happy Ending….It is interesting that CXL itself might be a

precipitating factor in causing keratitis

Group 2To analyse the profile of microbial keratitis occurring after

CXL

4 eyes developed infectious keratitis post CXLEtiology - moxifloxacin resistant Staphylococcus aureus (MXRSA)

These eyes were studied

1715 CXL, 310 TE-CXL and 325 A-CXL over 7 years who underwent CXL

2350 progressive KC patients

A Retrospective analysis

Case Clinical picture Associated

conditionsTreatment Procedure Management

1 Bronchial asthma Inhalational /oral steroids

Conventional CXL

Femtosecond Endothelial Keratoplasty

2 Vernal catarrh Topical steroids Conventional CXL

Rigid gas permeable contact lens

3 Eczema Oral Cyclophospha-mide

Conventional CXL

Penetrating Keratoplasty

4 Vernal catarrh Topical steroids Conventional CXL

Amniotic membrane graft , under follow-up

Keratitis after CXL - Clinical profile of patients

The Question Arises…

Cross –linking is treatment of

infectious keratitis

Cross-linking predisposing to keratitis

Pre –operative steroids:? altered flora

Ermis SS, Aktepe OC, Inan UU, Ozturk F, Altindis M. Effect of topical dexamethasone and ciprofloxacin on bacterial flora of healthy conjunctiva. Eye (Lond). 2004 Mar; 18(3):249-52

SYSTEMIC IMMUNOSUPPRESSION

LOCAL STEROID THERAPY

UVA induced:? Moxifloxacin

resistance

Ince D, Zhang X, Hooper DC. Activity of and resistance to moxifloxacin in Staphylococcus aureus. Antimicrob Agents Chemother. 2003 Apr;47(4):1410-5

Thank you