Microbial Keratitis in Corneal Transplants: A 12-Year Analysis

Figures & data

Table 1 Patient Demographics

		Total N (%)
Total episodes of keratitis		72
Number of grafts included		66
Age of patients at presentation* (years)		56 (20.7, 1–92)
Age of graft at presentation^φ (months)		25 (8–65)
Sex
	Males	37 (51)
	Females	35 (49)
Eye
	Right	39 (54)
	Left	33 (46)
Surgery
	Penetrating keratoplasty	67 (93)
	Endothelial keratoplasty	0 (0)
	Deep anterior lamellar keratoplasty	4 (6)
	Epikeratophakia	1 (1)

Notes: 6 grafts had more than 1 episode of keratitis; All figures Total (%) unless otherwise stated; *Mean, standard deviation, range; ^φMedian, interquartile range.

Table 2 Indication for Corneal Transplant Being Performed: Indication for Graft

	PK (n=67)	DALK (n=4)	Epikeratophakia (n=1)
Infection	22	–	–
Keratoconus	9	3	1
Keratoconus + hydrops	3	–	–
Fuchs endothelial dystrophy	7	–	–
Graft decompensation	7	–	–
Corneal decompensation	4	–	–
Pseudophakic bullous keratopathy	6	–	–
Other*	11	1	–

Notes: Total count greater than number of cases (n) as some cases recorded as more than one indication for graft; Other*, anterior segment dysgenesis, buphthalmos, corneal dystrophy, corneal melt secondary to rheumatoid arthritis, DALK interface vessels, descmetocele and mucus membrane pemphigoid, lipid keratopathy, peripheral ulcerative keratitis, Steven-Johnson syndrome, thermal injury, traumatic graft dehiscence, WAGR syndrome.

Table 3 Organism Identified from Corneal Scrape Sample

Organisms		Total (n=79) N (%)
Gram positive		58 (73)
	Staphylococcus aureus	20 (25)
	Coag. Negative Staphylococcus	13 (16.5)
	Other Staphylococcus
	MRSA	2 (3)
	Streptococcus pneumoniae	8 (10)
	Other Streptococcus	8 (10)
	AHS	4 (5)
	S. viridans	2 (3)
	GBS	1 (1)
	S. sanguinis	1 (1)
	Others	7 (9)
Gram negative		18 (23)
	Pseudomonas	4 (5)
	Moraxella	4 (5)
	Sphingomonas	3 (4)
	Serratia	2 (3)
	Haemophilus influenzae	2 (3)
	Others	3 (4)
Fungi		3 (4)
	Candida parapsilosis	2 (3)
	Candida albicans	1 (1)

Notes: Organisms identified from corneal scrapes of corneal graft; 5 episodes of keratitis were coinfections; Other gram positive, Diptheroids, Abiotrophia, Corynebacterium, Enterococcus, Finegoldia, Mycobacterium; Other gram negative, Citrobacter, E. coli, Stenotrophomonas.

Abbreviations: MRSA, methicillin resistant Staphylococcus aureus; AHS, alpha haemolytic Streptococcus; GBS, haemolytic Streptococcus group B.

Table 4 Age of Graft at Presentation Stratified According to Infective Organism

Infective Organism	Age of Graft at Presentation Months Median (IQR)
Gram +ve (n=50)	25 (8–55)
Gram -ve (n=14)	22 (4–121)
Coinfection (n=5)	58 (23–58)
Fungal (n=3)	13 (11–26)

Table 5 Antibiotic Susceptibility and Resistance in Both Gram-Positive and Gram-Negative Organisms

		Total Susceptible	Total Resistant	Susceptibility (%)
Gram positive (n=58)
	Chloramphenicol	45	3	94
	Vancomycin	41	0	100
	Gentamicin	32	3	91
	Ofloxacin	28	13	68
	Fusidic acid	25	4	86
	Ciprofloxacin	23	3	88
	Cefuroxime	17	3	85
Gram negative (n=18)
	Gentamicin	15	0	100
	Ciprofloxacin	13	1	93
	Chloramphenicol	12	0	100
	Amikacin	9	0	100
	Cefuroxime	9	4	69
	Ceftazidime	8	3	73
	Ofloxacin	8	3	73

Table 6 Potential Exacerbating Factors Present at the Time of Keratitis

Risk Factor	Total N (%)
Topical steroids	64 (89)
Topical glaucoma drops	23 (32)
Suture problem: loose or removed	19 (26)
HSV	18 (25)
Atopy/eczema	16 (22)
Decompensated graft	13 (18)

Table 7 Complications Occurring Within 1 Year of Keratitis Episode

		Total N (%)
Graft decompensation		8 (11)
Graft rejection episode		2 (3)
Perforation		9 (13)
Crystalline keratopathy		4 (6)
Orbital cellulitis		1 (1)
Endophthalmitis		1 (1)
Further surgery	Penetrating keratoplasty	14 (24)
	Evisceration	3 (4)