A study of clinical characteristics of secondary glaucomas in a tertiary eye care centre

INTRODUCTION

Glaucoma is the second leading cause of blindness globally as well as in most regions , with the prevalence of over 76 million people affected ( 2010 -2020)  1

Glaucoma is defined as a multifactorial optic neuropathy, which is characterised by progressive damage of retinal ganglion cells and axons, and a thinning of nerve fibre layer and neuroretinal rim.When a related  or identifiable ophthalmic condition is known to be present , it is secondary glaucoma, i.e., glaucomas that occur as a side effect or secondary to another underlying medical condition or trauma.This differs from primary glaucoma where there is no identifiable cause for glaucoma to develop.

 Previous studies have shown that secondary glaucoma occurred more in men than women in the age group of 51-60 years, commonly unilateral with intraocular pressure =/> 30 mmHg, most common lens induced glaucoma followed by steroid induced glaucoma 1.Other causes being neovascular glaucoma,traumatic , pseudoexfoliation, post vitrectomy.

Some studies also noted younger patients affected by secondary glaucoma and presentation with higher IOP, severe disc damage and visual field defects . 2

The management in secondary glaucoma differs from primary, as in secondary variety if the primary pathology is detected and treated at the earliest , glaucomatous damage can be prevented . 3

Need for the study

 Six million people are affected by secondary glaucoma globally compared to 67 million of primary glaucoma.The prevalence varies from 6-22% globally and 0.7 -6 % in India with varied etiologies. 4

The various causes of secondary glaucoma include ocular and systemic conditions , lens pathologies,trauma, neovascularization,steroid –induced,inflammation , previous surgery, and others which poses formidable diagnostic and management challenge. 5

For each of these conditions,understanding the clinical profile of patients, mechanism of raise of intraocular pressure (IOP) helps us to focus on the underlying condition  and plan accordingly.

As secondary glaucoma is an important cause of visual morbidity , early diagnosis and appropriate treatment can help in prevention of irreversible visual loss.

 Hence , this study is undertaken to investigate the characteristics of secondary glaucoma patients at a tertiary care hospital in Bangalore.

 Objective of the study

To study the demography,underlying etiology,clinical characteristics and disease severity of secondary glaucomas.

 MATERIALS AND METHODS

Source of data

Patients attending out patient department (OPD) of Nethradhadama superspeciality hospital , Glaucoma block, Bengaluru,Karnataka, India .

 Inclusion criteria

1.     Patients of either gender aged < 70 years, U/L or B/L , IOP >21 mm Hg, with or without glaucomatous disc damage with ;

2.     Lens induced changes

3.     Pseudoexfoliation syndrome

4.     Steroid usage

5.     Ocular trauma

6.     Ocular inflammation

7.     Neovascularizartion of eye

8.     Retinal pathology / vitreo retinal surgery,previous ocular surgeries.

 Exclusion criteria

1.     Not willing to participate

2.     Primary open –angle glaucoma (POAG) , primary angle closure glaucoma (PACG ), Congenital glaucoma

3.     Corneal opacity, degeneration,dystrophy or infections , which precludes IOP measurement by Goldmann applanation tonometer (GAT).

 Study design: Cross-sectional descriptive study

 Sample size: 60 consecutive patients

 In India, the reported prevalence of secondary glaucoma ranged between 0.7 to 6.72%.    Considering   3.7%   prevalence with 5%  error   sample needed to conduct this study  is   55 cases.   60  cases  will be    selected.

  Place of study: OPD, Glaucoma block , Nethradhama superspeciality hospital, Bengaluru, Karnataka.

 Method of collection of data

 Consecutive patients diagnosed as secondary glaucoma will be explained about the procedure and informed consent will be taken.

A detailed ophthalmic evaluation which includes the following:

 1.     Visual acuity – both uncorrected and best corrected using Snellens chart and Jaegers chart for near vision.

2.     Refraction with streak retinoscope or auto refractometer.

3.     Detailed slit lamp examination of anterior segment.

4.     IOP measurement by GAT.

5.     Posterior segment evaluation by slit lamp fundus biomicroscopy using a +90D lens or Indirect ophthalmoscopy.

6.     Gonioscopy using 4 mirror gonio lens.

7.     Visual field examination by HFA 3 ( CZ Meditech ) and Optical coherence tomography (OCT) for optic nerve head and peripapillary retinal nerve fibre layer analysis .

 Statistical Analysis

 Categorical  data will be represented in the form of frequency and percentage.   Association between variables will be  assessed with Chi Square Test.  Quantitative data will be   represented as  Mean & Sd. Comparison will be done with Independent t test.A P value of <0.05 will be  considered statistically significant.Data was analyzed with IBM SPSS Version 28 for windows.

  References

**1.**Komaratih, E., Rindiastuti, Y., & Primitasari, Y. (2020). Profile of Secondary Glaucoma at a Tertiary Hospital in East Java. Folia Medica Indonesiana, 56(1), 56–59.

2.     Seth PK, Senthil S, Das AV, Garudadri C. Prevalence of glaucoma types, clinical profile and disease severity at presentation: Tertiary Institute based cross-sectional study from South India. Indian J Ophthalmol. 2023 Oct;71(10):3305-3312.

3.     Gadia R, Sihota R, Dada T, Gupta V. Current profile of secondary glaucomas. Indian J Ophthalmol. 2008 Jul-Aug;56(4):285-9.

4.     Partha Chakma , Debal Kisor Pal , Amar Kanti Chakma.A Clinical Study of Secondary Glaucoma with Special Reference to Its Proportion, Causes and Its Risk Factors in a Tertiary Care Hospital - A Cross Sectional Study . J Evid Based Med Healthc, 2021 Jan ;eISSN - 2349-2570

5.     Gurung J, Sitoula RP, Singh AK. Profile of Secondary Glaucoma in a Tertiary Eye Hospital of Eastern Nepal. Nepal J Ophthalmol. 2021 Jan;13(25):98-103.