I grew up playing baseball, and I’ll never forget the feeling of hitting the ball on the sweet spot of the bat. It’s a distinct moment—smooth, powerful, and efficient. That kind of connection is what I strive for in glaucoma care: leveraging the right technology at the right time, in the right patient.
In addition to a fundus camera, gonioscopy lenses, a pachymeter, perimeter, and tonometer, here I discuss the diagnostic devices that hit the sweet spot in my practice. Further, I talk about devices I may soon add to my practice.
Ocular Response Analyzer
This device provides insight into the biomechanical properties of the eye, providing valuable metrics in glaucoma risk assessment. A lower corneal hysteresis is associated with faster rates of progression and a higher likelihood of conversion from ocular hypertension to glaucoma.¹
Electroretinogram (ERG)
While ERG has broader applications in retinal disease, I find it valuable in advanced glaucoma. Specifically, when structure reaches the proverbial floor, functional testing takes the lead, as visual fields are notoriously unreliable in such patients. ERG guides my clinical decisions when ocular coherence tomography (OCT) and visual fields offer diminishing returns.²
OCT-Angiography
I consider this a sweet spot because once the ganglion cell complex and retinal nerve fiber layer hit the measurement floor, OCT-A can still provide valuable progression data. Vessel density changes offer insights into disease activity and allow us to contin-ue monitoring disease progression, even in advanced glaucoma cases.³ That’s a game-changer for longitudinal care.
Anterior Segment-OCT
I use anterior segment-OCT from limbus to limbus to better understand angle dynamics, especially in narrow angle or angle-closure glaucoma suspects. It allows me to actually visualize iris configuration and the relative position of the lens, making it especially helpful in pre- and post surgical evaluations, such as after iridotomy or cataract extraction.⁴
Forthcoming Additions
Now, on to technologies that I don’t currently use, but may add to my practice. Doppler OCT is proving valuable in assessing blood flow in normal tension glaucoma. I follow the data on it closely. This technology could become crucial in cases in which blood flow may be more important than intraocular pressure (IOP).⁵
Home tonometry is another area of interest for me. We’ve all had patients whose IOP readings seem normal in the chair, but whose glaucoma still progresses. Self-tonometry, especially during nonoffice hours, can help uncover those elusive IOP spikes.⁶ Similarly, contact lens-based IOP monitors hold promise in mapping the 24-hour pressure circadian curve, something we currently infer more than measure.⁷
What’s Your Sweet Spot?
Glaucoma management is not about any one tool, it’s about applying technology to find the sweet spot for each patient. I have found that these technologies, in particular, help me do just that. What glaucoma diagnostics are in your sweet spot? Let me know at mycymbor@nittanyeye.com. OM
References
1. Zimprich L, Diedrich J, Bleeker A, Schweitzer JA. Corneal Hysteresis as a Biomarker of Glaucoma: Current Insights. Clin Ophthalmol. 2020;14:2255-2264. Published 2020 Aug 10. doi:10.2147/OPTH.S236114.
2. Hidaka T, Chuman H, Ikeda Y. Evaluation of inner retinal function at different stages of primary open angle glaucoma using the photopic negative response (PhNR) measured by RETeval electroretinography. Graefes Arch Clin Exp Ophthalmol. 2024;262(1):161-169. doi:10.1007/s00417-023-06193-z.
3. Moghimi S, Bowd C, Zangwill LM, et al. Measurement Floors and Dynamic Ranges of OCT and OCT Angiography in Glaucoma. Ophthalmology. 2019;126(7):980-988. doi:10.1016/j.ophtha.2019.03.003.
4. Abdeen W, Esmael AF, Gawdat G, El-Fayoumi D. Anterior chamber angle features in primary congenital glaucoma infants using hand-held anterior segment-oct. Eye (Lond). 2022;36(6):1238-1245. doi:10.1038/s41433-021-01583-1.
5. Yoshioka T, Song Y, Kawai M, et al. Retinal blood flow reduction in normal-tension glaucoma with single-hemifield damage by Doppler optical coherence tomography. Br J Ophthalmol. 2021;105(1):124-130. doi:10.1136/bjophthalmol-2019-315616.
6. McGlumphy EJ, Mihailovic A, Ramulu PY, Johnson TV. Home Self-tonometry Trials Compared with Clinic Tonometry in Patients with Glaucoma. Ophthalmol Glaucoma. 2021;4(6):569-580. doi:10.1016/j.ogla.2021.03.017.
7. Zhu H, Yang H, Zhan L, Chen Y, Wang J, Xu F. Hydrogel-Based Smart Contact Lens for Highly Sensitive Wireless Intraocular Pressure Monitoring. ACS Sens. 2022;7(10):3014-3022. doi:10.1021/acssensors.2c01299.
