Year : 2021 Month : October Volume : 10 Issue : 43 Page : 3670-3675,

Assessment of Clinical Outcome Following Therapeutic Penetrating Keratoplasty in Non-Healing Infective and Perforated Corneal Ulcer

C. Suria Rashmi1, Gajaraj Tulsidas Naik2, K. Satish3, Meghana Neeralgi4, Mohamed Abdul Kayoom5, Sheetal Vaijanath Zille6, C. N. Madhusudhana7, Amulya Padmini H.M.8

1, 2, 3, 4, 5, 6, 7, 8 Department of Ophthalmology, Mysore Medical College and Research Institute, Mysore, Karnataka, India.

CORRESPONDING AUTHOR

Dr. C. Suria Rashmi, Department of Ophthalmology, Mysore Medical College and Research Institute, Mysore, Karnataka, India.
Email : suria.chummi@gmail.com

ABSTRACT

Background

Corneal blindness has been a significant visual disability in developing countries like India. Corneal ulcer contributes mainly as the leading cause for monocular blindness. Considering the common condition, the studies and literature have been surprisingly less when it comes to corneal ulcer and their management. But with the advent of therapeutic penetrating keratoplasty (TPK), the scenario and prevalence of corneal blindness can be reduced. Hence this study was done to know the importance of therapeutic penetrating keratoplasty in case of non-healing infective and perforated corneal ulcers. The objectives were to assess the clinical outcome in a non-healing and perforated corneal ulcer, reduction in symptoms and signs of infection, anatomical or structural integrity of the globe and also evaluate the visual outcome following therapeutic penetrating keratoplasty.

 

Methods

Data were obtained from 30 patients operated at our institute for therapeutic penetrating keratoplasty. Patients with less than one year of follow up, paediatric cases, PL negative cases were excluded. The outcome was assessed based on maintenance of structural integrity, reduction in infective load, improvement in visual acuity and graft survival and its correlation with corneal vascularisation, previously failed grafts, donor tissue quality, graft size and type of surgery.

 

Results

Structural integrity was maintained in 93.3 % of the cases, reduction of infective load in 90 % of cases and optically clear grafts in 46.7 % of cases and vision was better than 6/60 in 30 % of cases.

 

Conclusions

The study proved that in the case of non-healing and perforated corneal ulcers, therapeutic penetrating keratoplasty had a good prognosis in reducing infective load, maintaining structural integrity without which eye could have been lost.

 

Key words

Therapeutic Penetrating keratoplasty, Perforated corneal ulcer, non-healing corneal ulcer, corneal blindness, TPK

BACKGROUND

Blindness has been a major health issue in India since its independence. To tackle it, the government introduced National Programme for Control of Blindness in 1976 which was a 100 % central scheme to reduce blindness to 0.3 %.

The main causes of blindness are cataract, refractive error, glaucoma, posterior segment pathologies etc. These compromise about 99 % of blindness and 0.99 % was due to corneal blindness.

Apart from cataract and refractive errors the next major cause of blindness in developing countries is corneal blindness, but depends on geographic area, health services and other factors to make it more prevalent.1

Corneal ulceration in developing countries has a great impact on morbidity and has been called a silent epidemic.2 A study done by Gonzales in the Madurai district of India showed 10-11 times more incidence of corneal ulcer when compared to Olmsted County in the US.3 The total occurrence of corneal ulcers in the same district was 850000 per year which was thirty times that of US.3 Linking the prevalence of corneal ulcers in India and other Asian and African countries the total count goes over 2 million. In the end, majority of cases result in corneal blindness or even worse like endophthalmitis and phthisical eye.

Bacterial keratitis is the most common cause of infective keratitis and a common cause of perforation. If the perforations are very large that can’t be plugged by tissue adhesives or glues they need keratoplasty.4 Corneal transplantation, where a diseased corneal tissue is replaced by donor corneal tissue in its entirety (penetrating) or in part (lamellar) is called keratoplasty. The various types of transplants are therapeutic, tectonic or reconstructive and optical.

We wanted to study the various aspects of therapeutic penetrating keratoplasty, including indications, pre-operative assessment, pre-operative infective load, surgical techniques, post-operative management, complications, post-operative reduction of infective load and post-operative structural and visual outcome. This procedure is done to eliminate the infection and re-establish the integrity of the globe with the best possible visual restoration. The study was done on patients, with non-healing and perforated corneal ulcers, attending OPD at KR Hospital, Mysore.

 

Review of Literature

Since the era of corneal transplantation, therapeutic keratoplasty has made wonders in the management of progressive corneal ulcers giving a 100 % cure rate in the bacterial cause. But visual prognosis depends on a lot of factors such as the causative agent, inflammation, graft size, donor material quality. The main purpose of the surgery was to re-establish the globe integrity and eradicate the infectious disease process. The secondary outcome being visual prognosis.5

The following are the results of therapeutic keratoplasty done at various institutes.

A 2-year retrospective study was done in an eye hospital.  Pleven showed anatomy integrity was maintained in all the cases included in the study. The results say that TPK is best for perforated corneal ulcers.6

One more study done at Ankara Training and Research Hospital, Turkey showed a good prognosis after TPK in both the infectious and non-infectious keratitis groups which was conducted on 24 eyes for 2 years. 23 patients had Snellens more than 6/12 after TPK.7

In a study done by J C Hill, both perforated bacterial corneal ulcers and controls were included. The result being about half of the subjects had visual acuity of more than 6/12 after TPK.8

In a study performed at Singapore National Eye Centre, more than 70 % of the patients had a therapeutic survival rate after TPK for one year.9

 

Objectives

  • To assess the reduction in signs and symptoms of infection following therapeutic penetrating keratoplasty.
  • To assess the anatomical or structural integrity of the globe following therapeutic penetrating keratoplasty.
  • To assess the visual outcome following therapeutic penetrating keratoplasty.

METHODS

The ethical and research committee of our hospital approved this study. Informed written consent was obtained from each participant. This was an interventional study conducted between January 2016 and June 2017.

 

Sampling Method

Purposive sampling method.

 

Inclusion Criteria

All patients undergoing therapeutic penetrating keratoplasty for non-healing ulcer, impending perforation and perforated corneal ulcer.

 

Exclusion Criteria

Non-healing corneal ulcer with endophthalmitis and PL negative individuals.

 

Sample Size

Estimated to be 30 subjects with formula.

 

 

Where P (prevalence) =0.88, level of significance = 5 %, absolute allowable error = 12 %, using estimator set up technique for proportion, the inflated sample size was 30.

 

 

  • Patients fulfilling the inclusion and exclusion criteria were explained about the condition and procedure and consent taken. Detailed examination including ocular and systemic was done in special proforma which was transferred to the master sheet. The data was processed for statistical analysis.
  • Patient details such as name, age, sex, socio-economic status, occupation, chief complaints, history of presenting illness, the time duration between onset and presenting to hospital, prior antibiotic treatment were collected.
  • Ophthalmic examination was done to assess the state of the diseased eye – site, size and depth of the ulcer, size and site of perforation or impending perforation, vascularisation of the cornea, scleral involvement, the inflammatory status of the eye and hypopyon.
  • B scan of the affected eye was done to assess any posterior segment pathology. Detailed examination was  done to assess the causative agent (bacteria, fungi, viral, acanthamoeba) by corneal scrapings and microbiological examination by the microbiologist at KR Hospital.
  • General examination to assess the diabetic and hypertensive status of the patient was done.
  • Patients were started on systemic broad-spectrum antibiotics and topical antibiotics and antifungal and cycloplegics.
  • Examination of donor tissue for size, quality of the graft and grading of donor cornea was done.
  • Therapeutic penetrating keratoplasty was performed under peribulbar anaesthesia or general anaesthesia by the ophthalmic surgeon.
  • Postoperative medications were continued and follow up examination on post-op day 1, day 7, day 15, day 30, thereafter monthly up to 1 year was done.
  • Post-op slit-lamp examination to assess the reduction in signs and symptoms, reduction in infective load, graft uptake, wound leak, graft transparency, visual acuity was done.

 

Statistical Methods Applied

Statistical analysis included descriptive statistics, inferential statistics, chi-square test and Cramer's V test. SPSS software version 16.0 was used.

RESULTS