^1,4Resident, ²HOD, ³Consultant, ⁴Resident, Department of Glaucoma, Dr M M Joshi Eye Institute Gokul Road, Hosur, Hubli, Karnataka, INDIA.

Email: sachinmantawar@gmail.com, kpkphubli@gmail.com, pravinsp0123@gmail.com

Table 1: Distribution of patients according to Age and gender

In present study primary angle closure suspects eyes were most common (61.42%), followed by PACG (20.00%) and primary angle closure (15.71%).

Table 2: Distribution of Eyes according to Diagnosis

In present study anterior chamber parameters in both the groups were more in group B (eyes of normal individual) than in group A (Angle closure glaucoma spectrum eyes). This difference was statistically significant in all parameters. Also ACV/AL, ACV/KERATOMETRY, ACV/WTW, ACV/LT were more in group B(eyes of normal individual) than group A(Angle closure glaucoma spectrum eyes) and this difference was statistically significant.

Table 3: Comparison of Anterior chamber Parameter

All anterior chamber parameters were more in PAC eyes than in PACS eyes and this difference was statistically significant in all parameters (p value <0.05) except in ACV/AL and in ACV/WTW. (P value>0.05)

Table 4: Comparison between PACS and PAC

In comparison between PACS and PACG for anterior chamber parameters, all parameters were more in PACS eyes than in PACG eyes, this difference was not statistically significant in all above parameters (p value>0.05)

Table 5: Comparison between PACS and PACG

In comparison between PACS and Acute Angle closure crisis, for anterior chamber parameters, all parameters were more in PACS eyes than in Acute Angle closure crisis eyes and this difference was statistically significant (p value <0.05) except in ACD.

Table 6: Comparison between PACS and Acute Angle closure crisis

In comparison between PAC and PACG for anterior chamber parameters, all parameters were more in PAC eyes than in PACG eyes and this difference was statistically significant (p value <0.05) except in ACA and ACV/WTW. (P value>0.05)

Table 7: Comparison between PAC and PACG

In comparison between PAC and Acute Angle closure crisis for anterior chamber parameters, all parameters were more in PAC eyes than in Acute angle closure crisis eyes and this difference was not statistically significant except in ACD, ACA which was significant.

Table 8: Comparison between PAC and Acute Angle closure crisis

In comparison between PACG and Acute Angle closure crisis for anterior chamber parameters, all parameters were more in PACG eyes than in Acute angle closure crisis eyes and this difference was not statistically significant (p value>0.05).

Table 9: Comparison between PACG and Acute Angle closure crisis

DISCUSSION

Glaucoma is a leading cause of irreversible blindness and managing glaucoma patients is a real challenge for ophthalmologists worldwide. Of the several causes for glaucoma, ocular hypertension (increased pressure within the eye) is the most important risk factor in most glaucomas, but in some populations, only 50% of people with primary open-angle glaucoma actually have elevated ocular pressure.⁸ Scheimpflug photography is the basis for a number of devices that can image the anterior segment. The technology is highly versatile, with potential applications in the areas of keratorefractive surgery, corneal biomechanics, corneal ectasia evaluation, anterior segment imaging, cataract grading, and surgical planning for femtosecond laser-assisted cataract surgery.^9,10 In our study, the comparison between group A (primary angle closure glaucoma spectrum) and group B (normal individual) with respect to anterior chamber parameters ACD, ACV, ACA. We have compared ACD, ACV, AC, ACV/AL, ACV/KERATOMETRY, ACV/WTW and ACV/LT parameters which were more in group B (normal individual) than in group A(primary angle closure glaucoma spectrum). DS Grewal Et al. conducted a prospective, cross-sectional observational study, 265 eyes of 265 consecutive patients underwent sequential Scheimpflug imaging, SD- ASOCT imaging, and gonioscopy. Correlations between gonioscopy grading, ACV, ACD, AOD 500 and TISA500 were evaluated. It was concluded that ACV measurements using Scheimpflug imaging outperformed AOD500and TISA500 using SD-ASOCT for detecting narrow angles.³ Mohammad Pakravan et al.¹¹ studied comparison between acute angle closure, PACS and normal eyes in which they mentioned that Mean anterior chamber volume was 72±18, 77±18 and 176±44 μl in these groups and were statistically significant. They also compared ACA, ACD and observed that it was statistically significant as in our study. Also anterior chamber volume in primary angle closure suspects before and after peripheral iridotomy in which they found significant difference. In another study by George et al.,¹² no significant difference in biometric values was found between angle closure glaucoma and occludable angles, however they were significantly different from normal eyes; this observation is also in line with our findings. Jong Rak Lee et al.,¹³ also studied ACA, ACD and ACV parameters before and after laser peripheral iridotomy and the difference was statistically significant and the basic parameters of ACV and deepest ACD and all of the advanced topographic ACD parameters (Central ACD, Mid1 ACD, Mid2 ACD, and Mid3 ACD) increased significantly in both the conventional and LPI plus iridoplasty groups. Matthew T. Feng et al.,¹⁴ studied ACD in normal individuals using Scheimpflug imaging mentioned that ACD did not vary significantly in the countries studied, with the notable exception of New Zealand. Surgeons should anticipate a greater likelihood of a shallow ACD when evaluating glaucoma patients Middle-aged subjects had more crowded anterior chambers than young subjects with similar axial lengths. Anterior chamber volume may be a more sensitive parameter to reveal this difference than a linear measurement of the anterior chamber depth. Anterior segment imaging modalities such as Scheimpflug imaging may help define and detect high risk eyes.

Limitations of present study were small sample size and short duration of study.

CONCLUSION

In present study all anterior chamber parameters were more in normal eyes compared to angle closure glaucoma spectrum and mean difference was significant. Scheimpflug imaging can be a very useful tool in differentiating angle closure glaucoma spectrum from normal individuals, but, it cannot differentiate between the patients within the spectrum like primary angle closure suspect versus primary angle closure versus primary angle closure glaucoma.

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