DOES GLAUCOMA PROGRESS AFTER REFRACTIVE SURGERY?

Glaucoma is not a contraindication for refractive surgery performed to remove glasses. However, is there any association between these surgeries and glaucoma progression?

A retrospective observational cohort study by Sujin and Rim, included 65 eyes of 65 patients with primary open angle glaucoma (POAG) who underwent refractive corneal surgery (RCS). 

Glaucoma progression was determined based on structural changes in optic disc/retinal nerve fiber layer (RNFL) photographs and/or visual field (VF) deterioration. 

Cox proportional hazards analysis was used to identify risk factors for disease progression. 

VF mean deviation (MD) and RNFL thickness progression rates obtained using a linear mixed-effects model were compared across tertile groups based on axial length (AXL) and central corneal thickness (CCT), respectively.

Over the follow-up period (mean: 9.1±2.9 y), 23 eyes (35%) exhibited glaucomatous progression. 

The progression group had significantly longer AXL (P<0.001), thinner CCT (P=0.009) compared with those in the stable group. 

Multivariate analysis identified longer AXL [hazard ratio (HR): 1.507, P=0.037] and thinner CCT (HR: 0.988, P=0.037) as significant predictors of glaucoma progression. 

VF MD declined faster in the middle and highest AXL tertile groups, whereas RNFL thinning was the most pronounced in the highest AXL tertile group. 

The lowest CCT tertile group exhibited the fastest VF MD decline and RNFL thinning.

Conclusion:

Patients with POAG and a history of RCS who present with longer axial length and thinner central corneal thickness, are at significantly higher risk of glaucomatous progression, highlighting the importance of vigilant long-term monitoring in these eyes.

REFERENCE:

Yeo S, Sung KR. Factors Associated With Glaucomatous Progression in Eyes With Prior Refractive Corneal Surgery. J Glaucoma. 2026 Mar 1;35(3):157-165. doi: 10.1097/IJG.0000000000002682. Epub 2025 Dec 17. PMID: 41474867.

GLOBAL BLINDNESS FROM GLAUCOMA

A population-based observational study was published by Sun et al, to estimate the global prevalence of blindness and vision loss caused by glaucoma, and to evaluate the impact of socioeconomic factors on it. 

The prevalence of blindness and vision loss due to glaucoma were obtained from the Global Burden of Disease Study 2017 database. The Human Development Index (HDI), inequality-adjusted HDI and other socioeconomic data were acquired from international open databases. 

In 2020, glaucoma caused 11% of all global blindness in adults aged 50 years and older.

In 2020, 4.13 million people aged 50 years and older suffered moderate and severe vision impairment, and 3.6 million were blind due to glaucoma. 

The prevalence of glaucoma varies among different nations and regions. It appears to be highest among persons of African descent (ranging from 6.5% to 7.3%), followed by East Asian populations (ranging from 2.59% to 3.54%). This may be compared with figures from European-derived populations, which have been reported to fall below 2.0%.

The overall prevalence worldwide was 81.5 (95% CI 69.9 to 95.0) per 100 000 in 1990 and 75.6 (95% CI 65.0 to 88.1) per 100 000 in 2017. The age-standardised prevalence of cases per 100 000 in 2017 was highest in African region (171.5, 95% CI 146.9 to 200.2) and lowest in Region of the Americas (61.1, 95% CI 52.6 to 70.7). 

In terms of annual change between 1990 and 2017, the greatest increase in the prevalence was in Côte d’Ivoire (108.3) per 100,000, while the greatest decrease was in Qatar (−167.1) per 100 000.

The prevalence of blindness and vision loss due to glaucoma in 2017 among men was higher than that among women (men vs women：6.07, 95% CI 3.79 to 8.81 vs 5.42, 95% CI 3.40 to 7.81) per 100 000. The prevalence for both sexes increased as age rose from 45 years to 95 years.

Among the six WHO regions, the highest age-standardised prevalence of blindness and vision loss due to glaucoma was in the Eastern Mediterranean between 1990 and 2005 and in the African region between 2006 and 2017. By contrast, the region of the Americas had the lowest prevalence during the most period from 1990 to 2017 (63.0 per 100 000 in 1990, and 61.1 per 100 000 in 2017).

With respect to income, the highest age-standardised prevalence was found in the World Bank’s low-income regions (157.2 per 100 000 in 2017), while the lowest prevalence was found in high-income regions (42.7 per 100 000 in 2017) with statistical significance (p<0.001).

Similarly, the age-standardised prevalence was highest in low-SDI regions (111.2 per 100 000 in 2017) and lowest in high-SDI level regions (40.3 per 100 000 in 2017) (p<0.001). SDI is a measure of sociodemographic development based on educational attainment, average income per capita and total fertility rate. SDI varies from 0 to 1, and a higher value suggests a higher educational attainment and per capita income, and a lower total fertility rate. 

The results showed that the worldwide age-standardised prevalence of blindness and vision loss due to glaucoma decreased from 81.5 per 100 000 in 1990 to 75.6 per 100 000 in 2017, and the prevalence increased with age and is higher among men. 

GNI per capita, expected years of schooling and age-standardised prevalence of cataract and refractive disorder was the associated factors with the prevalence of blindness and vision loss due to glaucoma when adjusting for the influence of socioeconomic factors and healthcare indicators.

Although the number of glaucoma patients aged 40–80 years was predicted to increase to 76 million in 2020, and the number of blind or visually impaired due to glaucoma increased by 0.8 million and 2.3 million from 1990 to 2010, respectively, age-standardised prevalence of blindness and vision loss due to glaucoma decreased between 1990 and 2017. This may be mainly explained by the revolution in diagnostic methods such as optical coherence tomography (OCT), OCT angiography and automated perimetry, which has made early detection of asymptomatic glaucoma possible, at least in high-income countries, where access to such technology is better. 

REFERENCE:

Sun Y, Chen A, Zou M, Zhang Y, Jin L, Li Y, Zheng D, Jin G, Congdon N. Time trends, associations and prevalence of blindness and vision loss due to glaucoma: an analysis of observational data from the Global Burden of Disease Study 2017. BMJ Open. 2022 Jan 6;12(1):e053805. doi: 10.1136/bmjopen-2021-053805. PMID: 34992115; PMCID: PMC8739070.

LOW DOSE HYDROCORTISONE IN OSD PATIENTS

 

This study reports the effects of topical low-dose preservative-free hydrocortisone on intraocular pressure in patients affected by ocular surface disease with and without glaucoma.

Similar product 

Purpose:

A study was performed by Filippelli et al, to investigate the safety and efficacy of short-term treatment for ocular surface disease (OSD) with topical low-dose (1.005 mg) preservative-free hydrocortisone in one hundred patients with and without glaucoma.

Methods: 

This was an open label non-randomized clinical trial. Patients with OSD with and without primary open-angle glaucoma (POAG) received topical low-dose (1.005 mg) preservative-free hydrocortisone twice daily in each eye for 2 weeks. All patients underwent a complete ophthalmological examination at baseline (T0) and at 1 (T1) and 2 (T2) weeks post-treatment. At each visit, the intraocular pressure (IOP) and the ocular surface disease index (OSDI) questionnaire scores were recorded; the Schirmer test was performed only at T0 and T2.

Results: 

The OSDI score significantly decreased in both the POAG and no-POAG groups (both p < 0.0001) after hydrocortisone treatment, with no difference between the two groups (p = 0.72). There were no significant differences in IOP and Schirmer test results between T0 and T2 in both treatment groups (p = 0.68 and p = 0.83, respectively).

Conclusions: 

Topical low-dose (1.005 mg) preservative-free hydrocortisone is safe and effective for improving OSD symptoms both in patients with and without POAG.

REFERENCE:

Filippelli M, dell'Omo R, Gelso A, Rinaldi M, Bartollino S, Napolitano P, Russo A, Campagna G, Costagliola C. Effects of topical low-dose preservative-free hydrocortisone on intraocular pressure in patients affected by ocular surface disease with and without glaucoma. Graefes Arch Clin Exp Ophthalmol. 2022 Jan;260(1):247-253. doi: 10.1007/s00417-021-05345-3. Epub 2021 Aug 18. PMID: 34406502.

CENTRAL CORNEAL THICKNESS (CCT)

1. Central cornea thickness (CCT) is regarded as an indispensable investigation in the workup of any glaucoma suspect patient.
2. There are several biological factors and genetic components that may influence glaucoma progression, which have been associated with thinner CCT. 
3. The CCT itself can be affected by several factors including ethnicity, age, sex, glaucoma medications, genetics, and the subtype of glaucoma. 
4. There is also variability in the measurement of CCT between difference types of devices. 
5. These factors need to be considered in the evaluation of glaucoma patients' CCT and its effect on interpretation of intraocular pressure (IOP) levels and risk stratification.
6. Thinner CCT is found more often in patients with normal tension glaucoma (NTG) and angle closure, African American and Japanese patients, those with more advanced glaucoma and is an independent risk factor in ocular hypertension (OHTN). 
7. Its predictive value in established glaucoma is not proven; however, it is important in interpreting IOP results and risk stratification. 
8. The association of CCT with biological factors and genetics in glaucoma will hopefully become clearer as the research expands in these areas.
9. The use of devices that measure IOP independently of CCT would help to overcome its influence; however, they are still not widely incorporated into general clinical practice. 
10. Despite many proposed mathematical models, correcting Goldmann Applanation Tonometry (GAT) IOP does not provide any benefit in the assessment or management of glaucoma. 
11. Correcting methods introduce other errors into the interpretation of the IOP results. In addition, the adjusted IOP is unlikely to improve tonometry as a screening tool for open angle glaucoma (OAG) in at-risk populations and is not necessary in population-based assessment. Therefore, attempting to “correct” IOP based on CCT does not provide any benefit in the assessment or management in the glaucoma or glaucoma suspect patient.

REFERENCE:

Belovay GW, Goldberg I. The thick and thin of the central corneal thickness in glaucoma. Eye (Lond). 2018 May;32(5):915-923. doi: 10.1038/s41433-018-0033-3. Epub 2018 Feb 15. PMID: 29445115; PMCID: PMC5944650.

LASER DOPPLER HOLOGRAPHY

Monitoring retinal blood flow appears crucial to understand the pathophysiology of ocular diseases such as glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD).

LDH setup 

Montage of LDH images

Laser Doppler Holography (LDH) is a full-field imaging technique that measures blood flow, specifically in the retina and choroid, by recording the interference between light backscattered by moving blood cells and a reference beam.

The LDH technique allows parallelized imaging, higher acquisition speed, and offline numerical processing.

It also allows full-field imaging, which is not possible with OCT angiography (OCT-A).

LDH, OCG, OCT-A, OCT

In LDH, the optical field serving as non-Doppler shifted light is a separate reference beam beating against the Doppler shifted optical field backscattered by the retina. This allows the power of the reference field impinging on the sensor to be altered and thus be able to work with very low exposure time. 

Interferograms are recorded with a high throughput camera and wideband measurements of the beat frequency of digitally reconstructed holograms are performed. 

The angiographic contrast is drawn from the Doppler spectral broadening of light backscattered by the retina and blood flow changes during cardiac cycles as revealed using a short-time Fourier transform analysis. Such short acquisition times in the realm of a single cardiac cycle are not possible with OCT-A.

The light source used in LDH is a 45 mW, single-mode, fiber diode laser (Newport SWL-7513-H-P) at wavelength λ = 785 nm. The retina is illuminated with a 1.5 mW constant exposure over 2.4 × 2.4 mm2 area.

The laser beam is focused in the front focal plane of the eye so that the light is collimated inside the eye and illuminates the retina on an extended area. 

A Polarizing Beam Splitter (PBS) cube is used in the object arm to illuminate the eye and collect the light backscattered by the retina.

The object and reference waves are combined using a non-polarizing beam splitter cube and they interfere on the sensor plane.

Power Doppler images drawn from the Doppler power spectrum density qualitatively show blood flow in retinal vessels over 512 × 512 pixels covering 2.4 × 2.4 mm2 on the retina with a temporal resolution down to 1.6 ms.

A study by Lecoge and colleagues found median postoperative decrease in IOP of 23 mmHg (20–25.5) was associated with an improvement in diastolic central retinal artery flow [EDV significatively increased (P = 0.029)], and resistivity index significatively decreased (P = 0.029). 

(R. Lecoge, P. Bastelica, M. Atlan, J. Buffault, E. Brasnu, M. Paques, C. Baudouin, A. LabbÃ. In vivo Doppler holography of the optic nerve head in glaucoma: Response to acute IOP decrease,Journal Francais d'Ophtalmologie, Volume 49, Issue 3,2026.)

CONCLUSION:

LDH is used for non-invasive, high-resolution imaging of blood flow in the retina and choroid, assisting in studying hemodynamics in healthy and diseased eyes. It offers coherent gain, allowing for high sensitivity, and enables digital aberration correction to improve image quality.

VISUAL FIELD PATTERNS IN GLAUCOMA: A SYSTEMIC REVIEW

INTRODUCTION:

Retinal nerve fiber bundles are arranged in a specific distribution. As the greater part is located in the central 30° area, most early glaucomatous visual field defects (VFDs) are detected within this region. 

Typical glaucomatous visual field patterns include nasal step, paracentral scotoma, arcuate-like defects, diffuse loss, and altitudinal defects. 

Footnote: The blind spot is located at 15° temporally, where the optic nerve leaves the eye.

PRIMARY OPEN ANGLE GLAUCOMA (POAG):

The nasal step is described as the most frequent and earliest VFD, followed by paracentral scotomas and arcuate-like defects. 

The superior hemifield is more affected than the inferior hemifield.

Repeatable diffuse visual field loss was seen in 4.4% of patients, the only sign of early glaucomatous visual field loss. 

Diffuse visual field loss is nonspecific and can be caused by various other factors such as cataract, extreme miosis, and unreliable performance of the perimetry.

Early diffuse visual field loss usually converts into well-defined pattern defects at later stages. 

INFLUENCING FACTORS FOR VFDs IN POAG:

Initial VFDs located in the superior hemifield were associated with greater disc ovality (maximum diameter of an ellipse fitted to disc contour/minimum diameter of an ellipse fitted to disc contour), β-peripapillary atrophy and thinner central corneal thickness.

VFD in the inferior hemifield was more frequently found in both insulin-dependent as noninsulin-dependent diabetic patients (odds ratio [OR] =1.8).

The presence of systemic risk factors for glaucoma (especially NTG) such as hypotension, migraine, Raynaud’s phenomenon, and sleep apnea was significantly higher in POAG as well as NTG patients with an initial parafoveal scotoma than in patients with initial nasal step.

In NTG, these above-mentioned systemic risk factors for glaucoma were more prevalent in patients exhibiting initial central scotoma than in patients with initial peripheral scotoma. These findings suggest that systemic vascular risk factors in POAG and NTG patients are associated with central VFDs.

Body mass index and smoking (measured in pack-years) were more strongly associated with a lower risk of paracentral VFDs (HR [hazard ratio] Body mass index [BMI] =0.67; HR smoking = 0.92) than with peripheral VFDs (HR BMI = 0.93; HR smoking = 0.98). The relation between cigarette smoking and POAG overall has been conflicting. Nicotine has been mentioned to have a neuroprotective role. 

NORMAL TENSION GLAUCOMA:

NTG patients show more localized VFDs and are characterized by deeper, more central, and more depressed VFDs compared to POAG patients. 

PRIMARY ANGLE CLOSURE GLAUCOMA:

In early disease stages, the VFDs are most common in the nasal area.

Jiang et al. and Sim et al. observed that (partial) arcuate defects were the most common types of VFDs in PACG eyes. Atalay et al. showed that the superior hemifield was more impaired than the inferior hemifield across the whole severity spectrum. In contrast, Lau et al. found no significant difference in visual field loss between the superior and inferior hemifield.

Following an acute episode of angle-closure, a hemifield defect was the most common VFD.

PROGRESSION OF VFDs:

Primary-open angle glaucoma:

The most common pattern of progression is the deepening of an existing scotoma, followed by expansion, rather than the development of new scotomas, emphasizing the importance of reliable baseline VF testing.

With increasing severity, the VFD showed progression to the center and progression toward a connection with the blind spot.

The initial parafoveal scotoma showed a characteristic pattern of progression in a retrospective study conducted by Su et al. The parafoveal scotoma in the superior hemifield initially had an arcuate pattern that first deepened 3° to 5° above fixation, then elongated toward the physiologic blind spot, and spread towards the nasal periphery, sparing the area corresponding to the papillomacular bundle. The inferior parafoveal scotoma, showed similar characteristics, but tended to be further away from fixation. POAG patients progress faster in the superior hemifield defects compared to the inferior counterparts. This difference is more pronounced in the central, paracentral, and nasal area.

Patients with initial damage in both hemifields had higher chances of glaucomatous progression.

Normal-tension glaucoma:

NTG patients progress more often in the paracentral area. NTG patients with lower heart-rate variability had faster central visual field progression than those with higher heart-rate variability. Other vascular factors, such as migraine and orthostatic dysfunction were also related to increased central visual field progression.

REFERENCE:

Vandersnickt MF, van Eijgen J, Lemmens S, Stalmans I, Pinto LA, Vandewalle EM. Visual field patterns in glaucoma: A systematic review. Saudi J Ophthalmol. 2024 Dec 26;38(4):306-315. doi: 10.4103/sjopt.sjopt_143_24. Erratum in: Saudi J Ophthalmol. 2025 Oct 13;39(3):286. doi: 10.4103/sjopt.sjopt_374_25. PMID: 39943959; PMCID: PMC11811403.

SCHWARTZ-MATSUO SYNDROME

Introduction:

Schwartz-Matsuo syndrome is a rare condition characterized by the triad of rhegmatogenous retinal detachment (RRD) (usually with peripheral breaks or oral dialysis), elevated intraocular pressure (IOP) with marked fluctuation, and cells in the anterior chamber. In cases of retinal detachments not associated with Schwartz-Matsuo syndrome, there is usually low IOP secondary to increased outflow by active pumping of aqueous humor through the exposed retinal pigment epithelium. However, IOP in Schwartz-Matsuo syndrome is elevated.

The syndrome was first described by Schwartz in 1973. He described the classic findings of elevated IOP and apparent iridocyclitis associated with RRD and open AC angles. In 1986 Matsuo et al. discovered photoreceptor outer segments on electron microscopy of the aqueous humor and theorized that the free photoreceptor outer segments blocked the trabecular outflow leading to elevated IOP.

Electron microscopy of aqueous humor in such patients has demonstrated photoreceptors outer segments. The photoreceptor outer segments and/or retinal pigment epithelium (RPE) pigment pass through a retinal break, leading to outflow obstruction in the trabecular meshwork. 

The syndrome presents with, or mimics, severe open-angle glaucoma. It can be mistaken for uveitis or uveitic glaucoma, but it does not respond to corticosteroids. There are no features of inflammation such as pain, redness or ciliary flush.

Following retinal detachment repair, IOP typically normalizes and prognosis is favorable.

Symptoms:

Patients typically present with complaints of unilateral blurry vision, eye pain, and nausea associated with the elevated IOP, as well as floaters, photopsia, and scotoma secondary to the retinal detachment. 

Risk Factors:

Shallow RRD involving the vitreous base (a shallow detachment allows for constant sloughing of dying photoreceptor outer segments and involvement of the vitreous base allows for the photoreceptor outer segments to gain access to the anterior chamber. An intact hyaloid would not allow them to reach the anterior segment).

Other risk factors include:

• Retinal dialysis or retinal tears at the ora serrata. 
• History of ocular trauma or surgery.
• Myopia, or lattice degeneration.

Diagnosis:

On examination, IOP is elevated, with marked fluctuation in pressures. Pigmented aqueous cells are present in varying number, but there are usually no other signs of uveitis. On gonioscopy, the anterior chamber angles are typically open; however, angle recession may indicate prior ocular trauma. Finally, there is retinal detachment with tears most commonly located at the ora serrata or non-pigmented epithelium of the pars plana or pars plicata. The retinal detachment is often shallow and involves a wide area, including the macula.

Identification of photoreceptor outer segments in the aqueous humor by electron microscopy assists in the diagnosis. OCT will demonstrate the presence of subretinal fluid indicative of retinal detachment.

Systemic examination (Marfan's syndrome or atopic dermatitis may help identify patients who are at risk of a retinal break around the ora serrata).

Routine assessment of the visual acuity and monitoring of IOP should be done.

Gonioscopy will show an open angle and can rule out other etiologies of increased IOP: angle recession, angle closure, peripheral anterior synechiae, neovascularization, and others.

Differential diagnosis:

1. Iritis: The anterior chamber findings in Schwartz-Matsuo syndrome are not inflammatory. The presence of anterior synechiae and keratic precipitates indicates an inflammatory condition which would rule out this condition. It should also be noted that the aqueous cells in Schwartz-Matsuo syndrome are unresponsive to corticosteroid treatment.
2. Open-angle or other secondary glaucomas should be considered, especially if it occurs in a patient with a history of blunt trauma.
3. Posner-Schlossman syndrome shows very mild anterior chamber inflammation with few cells and little flare, few fine keratic precipitates, and responds to steroid treatment.

Management:

Schwartz-Matsuo syndrome should be managed as a secondary cause of glaucoma, with first line treatment including repair of the retinal detachment and washout of the AC cellular debris. Typically, IOP returns to normal following retinal detachment repair. 

Immediate glaucoma management includes maximizing medical therapy before retinal surgery with oral carbonic anhydrase inhibitors with or without pilocarpine. Pilocarpine may help to open the trabecular meshwork pores but is associated with miosis and increased risk of retinal detachments.

Similar to the treatment of pigmented cells seen in pigment dispersion syndrome, laser trabeculoplasty should lower the IOP, but may not achieve satisfactory results. Additionally, laser trabeculoplasty may place patients at higher risk for post-operative IOP spikes given their compromised trabecular function. 

A tube shunt is preferred over trabeculectomy given the possible conjunctival scaring following retinal surgery and the risk of hypotony maculopathy with the use of antifibrotic agents in young, highly myopic patients. Tube shunts may induce diplopia via restrictive strabismus when combined with sclera buckle. An additional consideration is the timing of the tube shunt implantation, whether at the time of retinal surgery or not.

Prognosis:

Is usually good, with IOP returning to normal following successful RRD surgery.

HIGH PILLOW POSITION & IOP

Intraocular pressure (IOP) fluctuates significantly in response to body position. The IOP is lowest in the sitting posture and increases in the order of supine and lateral decubitus positions.

These changes are attributed to the increase in episcleral venous pressure and choroidal vascular volume. The uveal tissues also develop congestion and expansion from increased venous and arterial pressures in the orbit, contributing to the increased IOP.

Therefore, postural modification may serve as a potential adjunctive strategy for IOP management in glaucoma patients.

In a study by Liu et al, involving 144 glaucoma patients, IOP was measured and compared between the high-pillow position (head elevated by 20–35° using two pillows) and the supine position. Additionally, changes in jugular venous lumen in response to postural variation were evaluated via ultrasonography in 20 healthy volunteers.

The authors reported that, compared with the supine position, the high-pillow position was associated with significantly elevated IOP, increased 24-hour IOP fluctuation and reduced ocular perfusion pressure (OPP) (all p<0.001). 

Greater postural IOP fluctuation (ΔIOP) was observed in younger individuals (p=0.027) and patients with primary open-angle glaucoma (POAG) (p<0.001). 

Multiple regression analysis identified thicker central corneal thickness and the presence of POAG (vs normal-tension glaucoma) as positive predictors of larger ΔIOP changes (both p<0.05). 

Ultrasonography in healthy volunteers revealed significant constriction of both internal and external jugular venous lumen in the high-pillow position (all p<0.001), accompanied by an increase in maximum blood flow velocity of the internal jugular vein (p=0.013).

Therefore, compared with the supine position, the high-pillow position is associated with increased IOP and decreased OPP in patients with glaucoma, which may be linked to jugular venous compression. 

ADVICE: 

Patients with glaucoma may benefit from avoiding sleeping postures that induce jugular venous compression to mitigate postural IOP elevation.

REFERENCE:

Liu T, Hu M, Liu X, et al. Association of high-pillow sleeping posture with intraocular pressure in patients with glaucoma. British Journal of Ophthalmology. Published Online First: 27 January 2026. doi: 10.1136/bjo-2025-328037.

Key morphological determinants of optic nerve head biomechanics

 

Glaucoma is closely linked to optic nerve head (ONH) damage, particularly within the lamina cribrosa (LC).

Recent advances in optical coherence tomography (OCT) imaging and deep learning-based segmentation enable accurate reconstruction of patient-specific ONH geometries.

OCT-based approaches can directly quantify ONH biomechanics and LC strain, providing critical insights into the mechanical behaviour of ocular tissues.

Li and associates have developed an automated pipeline that converts routine OCT into patient‑specific finite element (FE) models and quantifies biomechanical and morphological determinants based on the unique individual ONH structures.

This study used OCT images of the ONH from a large cohort of healthy individuals and glaucoma subjects. The overall workflow followed a sequential pipeline.

Collectively, these results demonstrate the capability of the automated pipeline to (1) robustly segment ONH tissues from routine OCT images, (2) extract a comprehensive set of morphological parameters, (3) quantify LC strain across a large cohort, and (4) identify key determinants of biomechanical response through both statistical and machine learning approaches.

In the study, LC depth showed the strongest linear association with LC strain (r = −0.31). Other parameters with smaller associations included BMO radius (r = 0.17), pre-lamina volume (r =  −0.14) and mean choroidal thickness (r = −0.12). 

After adjusting for age and gender, glaucomatous eyes exhibited significantly lower LC strain than healthy eyes (coefficient = 0.0018, p = 0.011), suggesting potential tissue remodelling. 

The pre-lamina depth, LC curvature, BMO radius, and LC depth were also found to be influential predictors for ONH morphological changes, despite modest explained variance.

REFERENCE:

Li, Q., Zhan, B., Liu, T. et al. An automated optical coherence tomography to finite element analysis pipeline reveals key morphological determinants of optic nerve head biomechanics in glaucoma. Eye 40, 238–244 (2026).

MEDIEVAL ARABIC CONTRIBUTION TO GLAUCOMA

Arab medieval physicians/philosophers have contributed immensely to our early knowledge of glaucoma. 

They introduced the term zarqaa (derived from azraq, the word for blue in Arabic) to the condition which we now call glaucoma, a Greek term, which means greenish. The disease is even now called maa' (water)- or nuzool-azraq or nuzool aswad (black) in Arabian populations.

The origin of the term zarqaa is not entirely clear. The nonspecific word zarqaa was translated by some as viriditate oculi (green). Did this translation result from the blue-green ambiguity present in many languages, or was the translation influenced by observations by oculists and physicians? The answer remains unknown. However, there are a few theories which point towards a possible explanation.

It was observed that patients suffering from glaucoma had dilated pupils which caused the lens to become more prominent. This greenish blue hue of the lens could have led to the condition being diagnosed as zarqaa. It could also imply the color of the iris seen in some populations. According to some accounts the Arab and European (specially Roman) conflicts led to the antagonism of Arabs for the blue green eyes of the Europeans. This could have led to using their eye color with a negative perception in their writings.

Al-tabbari (916-986) was one of the first to diagnose glaucoma based on the raised eye pressure in those patients. See link for post on Tabari: 

https://ourgsc.blogspot.com/2019/05/abu-al-hasan-ali-ibn-sahl-rabbani-al.html

Abu Ali al-Husain Ibn Sina (c. 980–1037 AD), a Persian also known as Avicenna, believed the zarqaa pupillary hue could be associated with anterior prominence of the lens (or a forward displacement of the lens) and could occur in an acquired (pathologic) manner. It is amazing that the modern pathophysiology of closed angle glaucoma has been described based on the position of the lens. Ibn Sina explained hardening of the eye in zarqaa due to the intraocular humor thickening or coagulating, leading to the lenses being more difficult to displace. He and other authors diagnosed eye hardness through palpation. Ibn Sina mentioned a grave prognosis when the lens could not be moved around in the eye. According to him surgery in such a case has poor visual outcomes.

Some authors have mentioned that the Quranic verses also point to blue eyed people being sent to the hell fire during Qayamat (Day of judgement). Allah knows best. 

https://www.dovepress.com/article/supplementary_file/77471/77471.pdf

Jacques Guillemeau (1550–1613) of France cited Ibn Sina and wrote that glaucoma, or viriditas oculi, was incurable, and involved a dry, thick, and green lens.