TRAUMATIC CORNEAL LACERATION IN NORTHWESTERN NIGERIA

Abstract

Background

Corneal laceration is a partial or full thickness corneal injury resulting from direct or indirect ocular trauma. Cornea laceration generally leads to the development of corneal opacity which is a significant cause of blindness worldwide, particularly in developing countries where facility for corneal transplant is not readily available.

Clinical outcomes depend on causes, the part of cornea involved, and availability of skilled human resource and presence of corneal transplant services.

Aim

To assess the presentation, causes, and outcome of management of traumatic cornea laceration among patients at Federal Medical Centre (FMC), Birnin Kebbi, Kebbi, Nigeria.

Methodology

A one-year, retrospective review of all patients with traumatic corneal laceration who presented to eye clinic of Federal Medical Centre (FMC) Birnin Kebbi, Nigeria between November 2013 and October 2014. Information retrieved from the patient records included patient’s bio data, clinical features, presenting visual acuity (VA), agents of injury, surgical intervention and visual outcome after treatment. The data obtained were analyzed with SPSS version 16.

Results

Thirty two cases of traumatic corneal laceration presented during the study period. The age of study participants ranged from 2 years to 47 years with a mean of 15.28+12.46. 16 (50%) were children less than ten years old. There were 21(65.6%) males and 11(34.4%) females with male/female ratio of 1.9:1 and 20 (62%) cases of corneal lacerations occurred at home. Majority of injuries were inflicted with sticks in 9 (28.1%) cases followed by motor bike accidents in 6(18.8%). The left eye was mostly affected 18 (56.2%). Thirteen patients (40%) presented within 24 hours of injury while 16 (50%) presented within a week while one (3.1%) reported after two weeks. Presenting visual acuities in 28(90.6%) ranged from 6/12 to hand movement and no light perception in 3(9.4%). Associated injuries included uveal prolapsed 28(87.5), cataract 15(46.9%), vitreous haemorrhage 6(18.8%) and retinal detachment 1(3.1%). All the patients had examination under anesthesia and cornea repair carried out within 36-48 hours of admission in 28(87.5%) cases and within 7 days in the remaining 4 (12.5%) patients. One (3.2%) patient developed endophthalmitis. After 6weeks follow up, visual accuity of 6/60 and better were achieved in 9 eyes. There was a statistically significant correlation between the presenting visual acuity and visual outcome. However, no relationships exist statistically between age, sex, and agent of injury. The site of injury also shows statistical association with the visual acuity at six weeks follow up

Conclusion

from this study, we observed that traumatic corneal lacerations were significant causes of ocular morbidity especially in children; public eye-health education is recommended as a preventive measure.

Introduction

Corneal laceration is a partial or full thickness injury to the cornea1 and can result from direct trauma to the corneal typically from a metallic, plastic or other object impacting to breach the corneal layers with sufficient force2. Patients usually have an intensely painful eye and they often present with severe lacrimation and photophobia; usually vision is impaired.

Corneal laceration generally leads to the development of corneal opacity which is a significant cause of blindness the world over, more so in developing countries where facilities for corneal transplant are not readily available. 3 4 This study aims at detailing the causes, clinical features, management and outcome of traumatic corneal laceration.

Patients & Methods

A one- year retrospective review of all the patients with traumatic corneal laceration managed at the Federal Medical Centre, Birnin Kebbi, Kebbi State, Nigeria between November 2013 and October 2014, was done. The data obtained included the demographic data, clinical features: agents of injury, visual acuity (VA) at presentation, ocular complications; and VA as at 6 weeks follow-up. Patients with incomplete hospital records were excluded from the study. Data were analyzed using SPSS 16.0 statistical software (SPSS Inc., Chicago, IL, USA) to determine simple descriptive statistics. Variables were further compared using Chi-square test. P-values <0.05 were considered statistically significant.

Ethical clearance for the study was approved by Ethics and Research committee of Federal Medical Centre, Birnin Kebbi.

Results

Out of the 37 patients with traumatic corneal laceration 5 were excluded due to incomplete data and the 32 with complete data were analyzed. There were 21(65.6%) males and 11(34.4%) females with age ranged from 2years- 47 years with a mean age of 15.28± 12.46 and 50% of the patients were children as shown in Table 1. All the patients presented with pain, photophobia and reduced vision. Table 2 shows the causes of laceration while Table 3 shows the clinical features seen in the patients. The commonest causes of laceration were sticks 9(28.1%) followed by motor bike accident in 6(18.8%). Many patients 13(40.6%) presented within 24 hours of occurrence of injury, 16(15%) presented with one week of injury, 2(6.2%) presented between 8-14 days and only one (3.1%) patient presented after 15days of injury. The left eyes (18, 56.2%) were commonly involved. The predominant presenting visual acuity was perception of light (12, 37.5) followed by hand movement (10, 31.2) while 3(9.4%) patients presented with nil perception of light. All the patients had examination under anaesthesia and 28 (87.5%) had primary repair within 36-48 hours of admission and within 7 days of admission in the remaining 4 (12.5%) patients. More than 16(50%) had visual acuities worse than 6/60 while 9 (28.1%) attained VA of 6/60 or better. One (3.1%) patient developed endophthalmitis. Table 4 shows Correlation between Clinical feature and Visual outcome.

Table 1. Age/Sex distribution of patients with traumatic corneal laceration.

Age range	Frequency male	%	Frequency female	%	Frequency total	%
0-9	8	25	8	25	16	50
10-19	2	6.3	3	9.4	5	15.6
20-29	1	3.1	4	12.5	5	15.6
30-39	0	0	5	15.6	5	15.6
40-49	0	0	1	3.1	1	3.1
Total	11	34.4	21	65.6	32	100

Table 2. Objects of injury.

Agent of injury	Frequency	Percentage
Stick	9	28.1
Motor bike accident	6	18.8
Metallic nail	4	12.5
Cable wire	2	6.2
Plastic object	2	6.2
Stone	1	3.1
Metallic object	1	3.1
Others	7	21.9
total	32	100
Other causes of injury include donkey bite, cow horn, needle, rice stalk, millet stalk, horse wipe and glass explosion

Table 3. Clinical features seen in patient with cornea laceration.

CLINICAL FEATURE
INVOLVED EYE		FREQUENCY	%
Left eye		18	56.2
Right eye		14	43.8
Total		32	100
VISUAL ACUITY
	At presentation		At 6 weeks follow-up
VA	Frequency	%	Frequency	%
6/9	1	3.1	1	3.2
6/12	1	3.1	1	3.2
6/36	2	6.2	2	6.2
6/60	0	0	5	15.6
1/60	3	9.4	5	15.6
HM	10	31.2	9	28.1
PL	12	37.2	6	18.8
NPL	3	9.4	3	9.4
Total	32	100	32	100
Key: HM hand movement, PL perception of light, NPL nil light perception

Table 4. Correlation between clinical features and visual outcome.

Correlation	Correlation coeficient	Visual outcome at 6 weeks follow up
Age of patient	0.264	P= 0.536
Sex of patient	0.324	P=0.512
Agent of injury	0.258	P=0.501
Presenting VA	0.112	P=0.001
Site of injury	0.167	P= 0.028
There was a statistically significant correlation between the presenting visual acuity and visual outcome. However, no relationships exist statistically between age, sex, and agent and injury. The site of injury also shows statistical association with the visual acuity at six weeks follow up

Discussion

Penetrating eye injury involving the cornea usually leads to the development of corneal opacities5. It is the third most common cause of blindness after cataract and glaucoma5. It is also the leading cause of unilateral visual loss in children 5^-7; this was also the observation in this study where 50% (16) of injuries affected those less than 10 years old. This finding was similar to the report from an Ibadan study5.

Many of the patients in this series were males 21(65.6%). This finding is similar to the report from past studies3^-6, 8, 9 where the male gender had been found accounted for the majority of cases of ocular injuries. This might probably be due to aggressive nature of male gender.

About 20 (62%) of injuries in this study occurred at home which was similar to the findings of Mallika et al10.

Most of the causative agents reported were sticks and trauma from motor bike accident. This observation is similar to findings in other studies8, 11, 12 where sticks were documented as the commonest object of injury. Mselle13 reported stones, sticks and metallic objects as the commonest causes of injury. On the contrary, Omolase et al14 identified vegetative particle as the predominant cause of corneal injury in their study.

Other causes of corneal injuries found in this study included donkey bite, cow horn, needle, rice stalk, millet stalk, horse wipe and glass explosion as shown in Table 2. This diverse nature of causative agents is as a result of the different engagement in-terms of tasks assigned to different individual in the community where everyone both old and young are involved in the day to day family activities.

Ocular trauma may occur in either eye; however, the left eye was affected in majority of the patients. This is contrary to findings reported by Omolase et al 14 and Okoye 15 both in Nigeria, and by Mallika et al 10 in Malaysia; where right eyes were involved in the majority.

In this study, more than a third, 13(40.6%) presented early within 24 hours but with large central area of corneal involvement and or with ragged laceration which significantly affected visual outcome. Early presentation reported in this study is higher than that reported from a South African study where 25% presented within 24 hours of injury 12 but similar to findings by Omolase et al14 who reported that 37.9% of their patients presented within 24 hours. Only one (3.1%) person presented 2 weeks after the injury. This observation may be because of the severe nature of the injury sustained, laceration with uveal prolapsed and occurrence of other associated injury, thence early presentation. This is contrary to previous studies 5, 11, 16 where majority presented late and only a few presented early.

Despite early presentation, there is no statistical relation-ship between the time of presentation and visual acuity at both presentations (p = 0.162) as well at follow-up (p = 0.167).

In most of the patients, presenting visual acuity was poor with up to 38% had light perception and 3 (9.4%) patients had no light perception. This also agreed with Middle Eastern study 17, Ashaye et al4 and Nwosu 18 studies where the presenting visual acuity were poor in two thirds of their cases. This observation could be due to severe nature of the injury.

Corneal laceration involving the limbus extending centrally constituted majority of cases. Corneoscleral laceration occurred in 7 cases; this extensive laceration is difficult to manage and tend to have increased morbidity. This is similar to the finding in Baiyeroju-Agbeja et study5.

Though majority had surgery within 24-48 hours, others who had after 48 hours were due to financial constraint. The prognosis after traumatic corneal injury is strongly influenced by the nature of the injury and the extent of initial damage as reported by Omolase14 et al and Okoye 15et al in their studies. however, from this study, the presenting visual acuity and the site of injury are the only factors that correlate statistically with visual acuity at six week follow up. Visual recovery after treatment was discouraging only 9 (28%) patients attained vision ranging from 6/9 to 6/60 and also 9(28.%) had visual acuity of hand motion. This observation is similar to the findings from Ibadan5 study, where the visual outcome in most cases were poor as only 19.3% of 60 children had visual acuity of 6/12 or better postoperative though the study was mainly on children. This observation was also demonstrated in a previous study in developing country 19. In contrast, a Scottish study showed that the prognosis or outcome of ocular injuries have significantly improved with the vast majority having excellent visual outcome 20.

Limitations of the study were its retrospective nature and the small sample size.

Conclusions

Traumatic corneal laceration is a significant cause of uniocular morbidity and visual impairment; many of the causes are preventable. Public eye health education on preventive strategies will optimize visual outcome.