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Research Article | Volume 14 Issue 5 (Sept - Oct, 2024) | Pages 410 - 414
A study of Optic Disc Parameters in Patients with Peripheral Retinal Tears Following Acute Posterior Vitreous Detachment in a tertiary hospital in Central India
 ,
1
Professor (Designate), Dept. Of Ophthalmology, Nscb Medical College, Jabalpur. India
2
Dept. Of Community Medicine, Gmc, Chandrapur, India
Under a Creative Commons license
Open Access
Received
July 30, 2024
Revised
Aug. 31, 2024
Accepted
Sept. 10, 2024
Published
Oct. 2, 2024
Abstract

This researchwas done to investigate the association between optic disc parameters analyzed by optical coherence tomography (OCT) and the occurrence of peripheral retinal tears in patients with symptomatic posterior vitreous detachment (PVD). Methodology:  This cross-sectional study enrolled 150 patients with symptoms of acute PVD, who were allocated into two groups based on whether a peripheral retinal tear occurred or not. Observation And Results: When comparing the average retinal nerve fiber layer (RNFL) thickness (μm) between retinal tear and control groups, it was shown that patients with a retinal tear have a significantly higher (87.2 [95% confidence interval (CI), 84.47 to 89.9] vs 81.1 [95% CI, 77.81 to 84.46], P = 0.005) average RNFL thickness. Furthermore, we observed a significant difference (0.13, 0.06 to 0.22 vs 0.07, 0.04 to 0.1, P = 0.036, Mann–Whitney U-test) in the size of cup volume (mm3) between the tear and control groups, respectively. Linear regression showed a significant decrease (P = 0.03) in average RNFL thickness with increasing age, but without a significant difference between the two groups. There was no statistically significant difference between the tear and control groups in terms of rim area, disc area, and average cup-to-disc ratio. Conclusion: Patients with a higher average RNFL thickness and larger cup volume measured by OCT were more prone to develop a peripheral retinal tear. Increased peripapillary average RNFL thickness due to trauma and subsequent inflammation, possibly related to the more adherent posterior hyaloid membrane to the retina, may also indicate strengthened adhesions in the areas of the peripheral retina where retinal tears occur. OCT analysis of the optic nerve head may be used in everyday clinical practice as a predictor of the development of peripheral retinal tears in patients with symptomatic PVD

Keywords
INTRODUCTION

The vitreous humor is the gel-like structure of the human eye. It consists of the transparent tissue that makes up the vitreous and accounts for more than 75% of the total volume of the eye. Posterior vitreous detachment (PVD) results from degeneration and collapse of the vitreous, which causes the vitreous to separate from the inner retina. The incidence of this aging process is approximately 24% in people aged 50–59 years and as high as 87% in people aged 80–89 years. Visual disturbances such as stage floaters and/or flashes of light. (1, 2) In addition, a recent study has shown that the incidence of ocular complications in patients with PVD symptoms confirmed by ophthalmoscopy was 14%. OCT) is a widely used, noninvasive technique for delineating retinal vessels and peripapillary retinal nerve fiber layer (RNFL) thickness.

Although aging is often a degenerative process associated with retinal thinning, as confirmed by many studies (3,4) PVD patients with peripheral retinal tears have a higher vitreous response to mechanical injury during posterior vitreous membrane detachment, resulting in more severe lesions that may lead to at least transient peripapillary retinal thickening. >The purpose of this study was to determine whether there is a relationship between optic disc structure and peripapillary RNFL thickness and the incidence of peripheral retinal tears in patients with symptomatic PVD. We hypothesized that patients with peripheral retinal tears may have a greater inflammatory response resulting in a different OCT optic disc compared to patients without retinal tears.

MATERIAL & METHODS

This study was a prospective observational study done in a tertiary medical college in central India from 1stJan 2023 to September 2023 on 150 patients, 75 patients in 2 groups.

Patients were divided into two groups according to whether peripheral retinal tears were present on fundoscopic examination. 76 patients developed PVD with peripheral retinal tears, while 74 patients developed complete PVD without peripheral retinal tears (control group of this study). Studies on patients with diabetes, optic neuropathy, and malignant peripheral retinal degeneration were excluded. Malignant peripheral retinal degeneration is defined as areas of the peripheral retina with strong adhesion between the vitreous membrane and the retina (e.g., lattice degeneration), because these areas are susceptible to retinal tears during PVD. After mandatory evaluation, patients with peripheral retinal tears were treated with argon laser photocoagulation, while patients in the control group were scheduled for examination after two weeks unless symptoms were newly designed.

Data analysis was performed using MedCalc, version 20.211 (MedCalc Software Ltd, Ostend, Belgium). The Kolmogorov–Smirnov test was applied to test if variables are normally distributed. Continuous variables are expressed as the means ± SD or medians and interquartile range (IQR), and independent-samples t-test or Mann–Whitney U-test were used to evaluate statistical significance. Linear regression was used to test the association between variables. Statistical significance was set at two-sided P < 0.05.

RESULT

Between Jan 2023 and September 2024, 182 patients consulted the emergency department of the ophthalmological clinic due to PVD-related symptoms. 32 patients were excluded from the study due to insufficient data or poor signal strength on examination scans. Ultimately, we analyzed the data on 150 patients. The baseline demographic and clinical characteristics of the patients are presented in Table 1.

TABLE 1 showing age, gender and ASA grade-wise distribution of patients in 2 groups

 

Tear Group, n = 75

Control Group, n = 75

P value

Age (year)

65.39 (62.94 to 67.85)

68.97 (66.6 to 71.35)

0.037

Male sex

40 (52.7)

22 (29.8)

0.044

Axial length (mm)

24.15 [23.83 to 24.47]

23.62 [23.27 to 23.98]

0.029

Avg. RNFL thickness (µm)

87.18 (84.47 to 89.9)

81.14 (77.81 to 84.46)

0.005

Rim area (mm2)

1.33 [1.28 to 1.49]

1.34 [1.27 to 1.62]

0.442

Disc area (mm2)

1.88 [1.79 to 2.04]

1.92 [1.78 to 1.99]

0.970

Cup volume (mm3)

0.13 [0.06 to 0.22]

0.07 [0.04 to 0.1]

0.036

Avg. CDR

0.5 (0.46 to 0.55)

0.46 (0.4 to 0.52)

0.218

 

The analysis of optic nerve head and peripapillary RNFL thickness in the patients was performed using OCT.

Finally, there was no statistically significant difference between the tear and control groups when comparing rim area, disc area or cup-to-disc ratio parameters.

The distribution of retinal tears per quadrant is presented in Table 2.

Table2: Distribution of patients according to surgical procedure

Quadrant

Total Number

Percentage

Upper temporal

54

71.1

Upper nasal

10

13.2

Lower temporal

7

10.5

Lower nasal

4

5.3

 

Figure 1: Compare of axial lengths between groups

 

OCT Analysis

The analysis of optic nerve head and peripapillary RNFL thickness in the patients was performed using OCT.

When comparing the axial length (mm) between the tear and control groups, a significant difference was observed between the groups (IQR, 23.83 to 24.47 vs 23.27 to 23.98, P = 0.029, Mann–Whitney U-test) (Figure 1).

 

The linear regression showed that younger patients had a significantly (P < 0.001) longer axial length in comparison with older patients (Figure 2).

Figure 2: Relationship between axial length and age; a linear regression.

 

Furthermore, when comparing the average RNFL thickness (μm) between the tear and control groups, patients with retinal tears had a significantly greater average RNFL thickness (87.18 [95% confidence interval (CI), 84.47 to 89.9] vs 81.14 [95% CI, 77.81 to 84.46], P = 0.005) (Figure 3).

 

Figure 3:         Comparison of RNFL thickness between groups.

 

Average RNFL thickness showed a significant decrease in linear regression analysis (P = 0.029) with increasing age; however, there was no significant difference in decreasing linear regression with age between the tear and control groups (Figure 4).

 

Figure 4: Relationship between RNFL thickness and age; a linear regression

The size of cup volume (mm3) was significantly different between the two groups (IQR, 0.06 to 0.22 vs 0.04 to 0.1, P = 0.036, Mann–Whitney U-test), as is shown in Figure 5.

 

Figure 5: Comparison of cup volume between groups.