Middle East African Journal of Ophthalmology

REVIEW ARTICLE
Year
: 2021  |  Volume : 28  |  Issue : 1  |  Page : 36--50

A case–cohort study of exfoliation risk factors and literature review


Ahmad M Mansour1, Anastasios G. P Konstas2, Hana A Mansour3, Abdul R Charbaji4, Khalil M El Jawhari5,  
1 Department of Ophthalmology, American University of Beirut; Department of Ophthalmology, Rafic Hariri University Hospital, Beirut, Lebanon
2 Department of Ophthalmology, Aristotle University, Thessaloniki, Greece
3 Department of Ophthalmology, American University of Beirut, Beirut, Lebanon
4 Department of Statistics and Research Methodology, Lebanese American University; Department of Statistics and Research Methodology, Lebanese University, Beirut, Lebanon
5 Department of Ophthalmology, Medical University of Lodz, Lodz, Poland

Correspondence Address:
Prof. Ahmad M Mansour
Department of Ophthalmology, American University of Beirut, Beirut
Lebanon

Abstract

The purpose of the study is to evaluate the risk factors associated with exfoliation in a case-cohort setting and literature review. This single-center, prospective, case-cohort study was carried out from January 2010 to April 2020 on patients operated for cataract surgery by a single surgeon in Lebanon. Forty-nine consecutive patients with exfoliation syndrome (XFS) and 62 consecutive control patients were identified and further investigated for selected systemic (diabetes mellitus, systemic hypertension, asthma, or atopy) and ocular variables (baseline vision, severity of nuclear sclerosis, glaucoma, eye rubbing, history of dry eye, or allergic eye disease). The mean baseline Snellen visual acuity was 20/283 in XFS versus 20/145 in control cases (P = 0.012). XFS also demonstrated significantly denser nuclear sclerosis than controls (P = 0.00958). By univariate analysis, allergic conjunctivitis (15 [30.6%] vs. 2 [3.2%]; P < 0.001), dry eye (20 [40.8%] vs. 13 [21.0%]; P = 0.0133), and habitual rubbing of the eyes (33 [67.3%] vs. 19 [30.6%]; P < 0.001) were associated with the presence of XFS. Habitual ocular rubbing was closely associated with allergic conjunctivitis (odds ratio [OR] = 13.0; 95% confidence interval [CI]: 2.8–58.8; P = 0.032). After multivariable analysis, the following variables showed significant results: glaucoma (OR = 34.5; 95% CI: 4.4–250; P = 0.010), duration of surgery (OR = 5.6; 95% CI 2.43–12.9; P < 0.001), and habitual ocular rubbing (OR = 4.42; 95% CI: 1.97–9.90; P = 0.029). This study shows a novel potential correlation between eye rubbing and XFS in a Lebanese cohort. Chronic eye rubbing induces or may exacerbate preexistent zonular damage in subjects with XFS, hence the need to better manage concurrent ocular surface disorder in these patients.



How to cite this article:
Mansour AM, Konstas AG, Mansour HA, Charbaji AR, El Jawhari KM. A case–cohort study of exfoliation risk factors and literature review.Middle East Afr J Ophthalmol 2021;28:36-50


How to cite this URL:
Mansour AM, Konstas AG, Mansour HA, Charbaji AR, El Jawhari KM. A case–cohort study of exfoliation risk factors and literature review. Middle East Afr J Ophthalmol [serial online] 2021 [cited 2022 Jul 2 ];28:36-50
Available from: http://www.meajo.org/text.asp?2021/28/1/36/315319


Full Text



 Introduction



Exfoliation syndrome (XFS) is currently a global disease affecting an estimated 70 million people, worldwide.[1] XFS appears to be a syndrome targeting ocular tissues with deposition of fibrillary material on the lens capsule with similar deposits in other parts of the body, such as the skin, kidneys, liver, heart, and lungs. XFS material is a mixture of several biologic components made of amyloid, laminin, elastic fibers, and collagen basement membrane.[2] The causes of XFS are not well known,[3],[4] especially with animal models lacking,[5],[6] leaving researchers with the human Tenon's capsule fibroblasts as a model system for the study of XFS.[7] Advanced age appears as a major risk factor as well as some genetic factors.[8] Some evidence exists for the association between XFS and lysyl oxidase-like 1 (LOXL1) protein gene implicated in elastin formation and maintenance and less so with the calcium channel protein gene CACNA1A, and the extracellular matrix chaperon clusterin protein. Known environmental risk factors for the disease have included solar exposure,[9] ambient temperature, living at more northern latitudes,[10] dietary factors,[9],[11] and infectious etiology.[12] The possible relationship between XFS and selected ocular and systemic factors was investigated in a Lebanese cohort.

 Methods



This is a prospective data registry of all patients undergoing phacoemulsification in one surgical suite by a single surgeon (AMM) from January 2010 to April 2020. All patients provided written informed consent in accordance with the Declaration of Helsinki. Institutional Review Board (Rafic Hariri University Hospital, Beirut, Lebanon) approval was obtained for this study. Data were anonymized to maintain confidentiality. Systemic factors recorded have included age, gender, hypertension, diabetes mellitus, coronary artery disease, morbid obesity, Alzheimer neurodegenerative disorder, and intake of alpha agonists for benign prostatic hypertrophy and any major disease (migraine, cancer). Recorded ocular factors were preoperative and postoperative best-corrected visual acuity (BCVA), intraocular lens power, presence of XFS, glaucoma, macular degeneration, and diabetic retinopathy. Seven hundred and fifteen patients (mean age: 74 years) were enrolled in this study, and 387 of them underwent bilateral cataract removal. Surgeries were performed on 1097 eyes (599 right eyes and 498 left eyes) and were nearly equally distributed among men (509) and women (588). A case–cohort study was designed in which cases with XFS and controls without XFS were drawn from within this large prospective study. We selected a consecutive (most recent to less recent date of surgery) control group. In addition, we conducted a survey on these two groups to collect additional ocular and systemic variables between January 2010 and April 2020 (approved by the Institutional Review Board at Rafic Hariri University Hospital). This survey was done by phone call to answer the presence of habitual ocular rubbing before glaucoma topical therapy, history of therapy for either dry eye or allergic conjunctivitis, skin atopy or asthma, erectile dysfunction, and sensorineural hearing loss. The survey was carried by a blinded operator (KAJ). The subjects who answered positively for ocular rubbing (before glaucoma therapy) were contacted a second time to fill an ocular rubbing score.

We included all patients with significant cataract and visual acuity 20/40 (6/12) or less and with any accompanying ocular morbidity (keratoconus, XFS, glaucoma, maculopathy, reduced endothelial cells [<1800 cells/mm2], and central corneal opacity) or systemic morbidity (controlled diabetes mellitus, controlled systemic hypertension, stable stroke, and controlled angina) and Alzheimer's disease or adult Down's syndrome. Exclusion criteria included refusal to sign an informed consent, recent conjunctivitis of any kind, uncontrolled systemic hypertension or diabetes mellitus, active proliferative diabetic retinopathy, active untreated neovascular macular degeneration, Marfan syndrome, homocystinuria, systemic amyloidosis, true XFS[13] (history of radiotherapy, glass blowing, excessive heat exposure from oven burning or metal welding), and eyes that require concomitant vitrectomy (for vitreous hemorrhage or retinal detachment).

Preoperatively, we carried out slit lamp examination, before and after pupillary dilatation, with one drop of tropicamide (Mydriacyl® 1%, Alcon, Fort Worth, Texas, USA), fundoscopy, tonometry, measurement of BCVA, and ocular measurement with an optical biometer (IOL Master 700; Carl Zeiss Meditec AG, Jena, Germany). Target refraction was emmetropia. In the final analysis, only the first operated eye in subjects with bilateral exfoliation was included. In the control group, the first operated eye of consecutive subjects without XFS was enrolled. BCVA was measured by the same surgeon (AMM) using Snellen visual charts. Nuclear hardness was graded after pupillary dilation on the slit lamp (Haag-Streit® slit lamp 900 [Haag-Streit AG, Koeniz, Switzerland]) by the same surgeon using the 5-level Emery-Little Classification System (soft, semi-soft, medium hard, hard, and rock-hard). Glaucoma diagnosis relied upon intraocular pressure above 21 mmHg, glaucomatous optic disc cupping >0.7, and typical glaucoma-related visual field loss. A rubbing score has been designed to assess numerically the intensity of the ocular friction [Table 1].{Table 1}

Statistical analysis

Statistical analyses were performed using SPSS version 22 (IBM, Chicago, IL, USA), and t-test was used for testing the difference between the means of two independent samples. Multivariate analysis was carried using simple discriminant analysis when the dependent variable is categorical variable broken into yes and no using ANOVA and confirmed by cross-tabulation and Pearson's Chi-square test. Significance is set at P < 0.05.

Literature search

The databases of Medline, Embase and Google Scholar were systematically searched by one of us (AMM) for relevant articles published between 1975 and May 2020 using the search terms: exfoliation or pseudoexfoliation AND risk factors; exfoliation or pseudoexfoliation AND young age and using forward searching, checking references in major reviews (on exfoliation/pseudoexfoliation), and in all retrieved articles. Only comparative studies showing positive results with statistical significance set at P < 0.05 for the associated risk factors were included in the final tabulations.

 Results



The number of surveyed patients was 49 in the XFS group and 61 in the control group [Table 2] and [Table 3]. The completion rate of telephone survey approached 100% as patients or their close relatives (in case of death) completed the survey, for example, the survey in the control group was completed by 57 patients or by their mates in four deceased patients (100% response); likewise, the survey in the XFS group was completed by 45 patients or by their mates in 3 of 4 deceased patients (98% response). All enrolled subjects were Caucasians. The two groups were not different for gender, diabetes mellitus, coronary artery disease, or morbid obesity [Table 2]. XFS patients had longer follow-up because of the need to monitor for future or current glaucoma. XFS group was significantly older (by 7.4 years) than the control group. There was no significant difference for the presence of diabetes mellitus, systemic hypertension, coronary artery disease, morbid obesity, asthma or skin atopy, sensorineural hearing loss, or use of oral alpha-agonist for benign prostatic hypertrophy. Erectile dysfunction occurred in 12 of 22 XFS males (54.5%) versus 3 of 17 control males (17.6%) (P = 0.0069). Additional systemic findings in the XFS group not listed in [Table 2] included migraine in 4, rheumatoid arthritis in 3, stroke in 2, and temporal arteritis or sarcoidosis or interstitial lung fibrosis or colon cancer or lung cancer or toxic goiter or Parkinson's or sleep apnea in one case each. Additional systemic findings in the control group included breast cancer in two cases and sleep apnea or carotid stenosis or Parkinson's or migraine in one case each.{Table 2}{Table 3}

Eye-wise, the two groups were not different for baseline astigmatism, presence of posterior subcapsular cataract, baseline refraction (measured indirectly by the inserted intraocular lens power), and final BCVA [Table 3]. The two groups were different in terms of several ocular characteristics. The mean baseline spectacle-corrected Snellen visual acuity was 20/270 in the XFS versus 20/145 in the control (P = 0.032). Duration of surgery was near double in XFS than in controls (36.0 min vs. 17.4 min; P < 0.001), partly from higher grades of severity of nuclear sclerosis in the eyes with XFS (P = 0.023). Glaucoma (18 [36.7%] vs. 1 [16.1%]; P < 0.001), allergic conjunctivitis (before glaucoma therapy) (17 [34.7%] vs. 2 [3.2%]; P < 0.001), dry eye (before glaucoma therapy) (21 [42.9%] vs. 13 [21.0%]; P = 0.0074), and rubbing score of the eyes (before initiation of glaucoma medical therapy) (8.69 vs. 2.11; P < 0.001) were significantly more common in the XFS group. Other ocular findings in six patients with XFS and not listed in [Table 2] included: Sjogren's syndrome in 3, chronic anterior blepharitis in 2, severe ocular rosacea in 2, and large old herpetic corneal scar in 1, while a single patient in the control group had chronic anterior blepharitis.

A multiple regression was run to predict the potential risk factors for XFS [Table 4]. These variables significantly predicted the occurrence of XFS (F = 6.68; P < 0.001; R2 = 0.642): duration of cataract surgery (P < 0.001), glaucoma diagnosis (P = 0.004), history of local therapy for allergic conjunctivitis (P = 0.044), and ocular rubbing score (P < 0.001).{Table 4}

For XFS patients, 48 completed the survey, 30 admitted rubbing, and 18 denied rubbing. Of note, 23 XFS patients were witnessed rubbing the eyes in the clinic (all before any potential therapy for glaucoma). Severity of rubbing: 3 severe, 10 moderate, and 17 mild; frequency of daily rubbing: more than 10 times in 6, between 5 and 10 in 1, and <5 times in 23; rubbing was throughout the year in 13, seasonal in 6, and occasional in 11. Years of rubbing: 10 reported >20 years, 8 had between 11 and 20, 8 had between 6 and 10, and 4 had <6 years. For the 61 control patients who completed the survey, 14 admitted rubbing and 47 denied rubbing. Five control patients were witnessed ocular rubbing in the clinic (all before any potential therapy for glaucoma). Severity of rubbing: 1 severe, 2 moderate, and 11 mild; frequency of daily rubbing: more than 10 times in 1 and <5 times in 13; rubbing was throughout the year in 4, seasonal in 4, and occasional in 6. Years of rubbing: 4 had >20 years, 1 had between 11 and 20, 4 had between 6 and 10, and 5 had <6 years.

Literature review of positive risk factors for XFS in general [Table 5], [Table 6], [Table 7][14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36],[37],[38],[39],[40],[41],[42],[43],[44],[45],[46],[47],[48],[49],[50],[51],[52],[53],[54],[55],[56],[57],[58],[59],[60],[61],[62],[63],[64],[65],[66],[67],[68],[69],[70],[71],[72],[73],[74],[75],[76],[77],[78],[79],[80],[81] and XFS in young subjects [Table 8][82],[83],[84],[85],[86],[87],[88],[89],[90],[91],[92],[93],[94],[95],[96],[97],[98],[99] was tabulated and this information was used to synthesize the literature findings with the current study findings.{Table 5}{Table 6}{Table 7}{Table 8}

 Discussion



In the Lebanese cohort under investigation, XFS was associated with advanced age, glaucoma, habitual ocular rubbing, and longer time for cataract surgery. While advanced age [Table 6],[39],[40],[41],[42],[43],[44],[45],[46],[47],[48],[49],[50],[51],[52],[53],[54],[55],[56],[57],[58],[59],[60],[61],[62],[63],[64],[65],[66],[67],[68],[69],[70] glaucoma [Table 5],[14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36],[37],[38] and longer surgery duration[100] are well established risk factors for XFS [Table 5],[14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36],[37],[38] ocular rubbing has received little attention in the literature.

What are the causes of ocular rubbing in exfoliation syndrome?

A major precipitating factor in the cohort under investigation is the presence of dry eye and to a lesser extent the presence of allergic conjunctivitis. Rubbing was associated in the current study with dry eye, and dry eye is a known feature in XFS patients.[101] XFS patients have lower basal tear test scores, decreased tear breakup time, loss of goblet cell density (by impression conjunctival cytology),[101] and significant Meibomian gland dysfunction.[23] These ocular surface disorders have been attributed partly to deposition of exfoliation material in the conjunctiva.[102],[103] Possible other explanations have included: degenerative disease of the ocular surface with deposition of neurodegenerative proteins similar to that found in Alzheimer's or Parkinson, autoinflammatory disease of the conjunctiva, and vascular insufficiency [Table 9]. Allergic conjunctivitis was also associated with rubbing but to a lesser extent in the present Lebanese study with one subject having XFS and vernal catarrh. Asthma and abnormal pulmonary function tests (obstructive airway disease) have been associated with XFS [Table 6].[39],[40],[41],[42],[43],[44],[45],[46],[47],[48],[49],[50],[51],[52],[53],[54],[55],[56],[57],[58],[59],[60],[61],[62],[63],[64],[65],[66],[67],[68],[69],[70] Batur et al.[66] in 60 patients with XFS without pulmonary disease detected a significant decline in pulmonary function tests versus 52 controls matched for age, gender, and smoking history. Similarly, in the Reykjavik Eye Study, a population-based study involving 1045 subjects (108 XFS) followed for 5 years, asthma was significantly associated with XFS (odds ratio 1.91; [95% confidence interval 1.00–3.62]) by multivariate analysis.{Table 9}

What are the consequences of ocular rubbing on the eye?

Acute rubbing of the eye can cause transient astigmatism,[107],[108] elevated intraocular pressure,[109],[110] and corneal hydrops.[111] Chronic rubbing has been linked with the development of keratoconus,[112],[113] cataract,[114] optic disc cupping,[115] and retinal detachment.[116] Küchle[84] reported 2 young subjects with keratoconus necessitating penetrating keratoplasty at ages 31, 37 and 40 years with XFS detected between 4 and 6 years after surgery. Küchle attributed this temporal relationship to possible slow virus transmitted from the donor cornea. We propose that rubbing caused the concomitant keratoconus and XFS. This is further confirmed by analysis of XFS in young subjects [Table 8]:[82],[83],[84],[85],[86],[87],[88],[89],[90],[91],[92],[93],[94],[95],[96],[97],[98],[99] Half of young subjects with a reported risk for XFS had keratoconus. Out of 35 subjects with XFS under 45 years of age, detailed clinical data were available in 18:9 having some kind of corneal ectasia and 9 having had intraocular surgeries (2 after penetrating trauma and 7 had primary glaucoma). The decreased endothelial cell count in XFS[28] could be due to XFS material accumulation[30] or from eye rubbing as rubbing per say decreases endothelial cell density.[117],[118]

Zonular stretching in health, trauma, and exfoliation syndrome

The function of the zonules is mechanical with its relatively elastic fibers able to stretch up to four times their original length before breaking, but this elasticity declines markedly with age. Biochemically, a zonule consists of a microfibril backbone comprised fibrillin and a restricted set of glycoproteins (80% being FBN1 and LTBP2).[119] LOXL1, a crosslinking enzyme responsible collagen and elastin biogenesis, is detected at significant levels, and this enzyme is implicated in the pathogenesis of XFS. Assia et al.[120] tested the stretching capability of lens zonules in 40 postmortem human eyes. They found that zonules can slowly stretch up to 3.82 mm in young subjects before rupturing. That value of maximal zonular stretch tended to decrease with the age by 0.5 mm for every 5 years in normal eyes, while eyes with XFS had even more friable zonules. Similarly, Saber et al.[121] found a median mechanical zonular stretch tolerance of 3.00 mm on postmortem eyes that previously had extracapsular extraction. The zonular apparatus is involved extensively in XFS. Ultrasound biomicroscopic grading of zonular changes in XFS included uneven and disrupted zonules, followed by patchy deposits on the zonules. A more severe grade involves diffuse granulation over thickened zonules[122] with web-like structure in between zonules. The end stage is extensive loss of zonules.[123] Similarly, occult zonular defects were present on ultrasound biomicroscopy in 21 of 49 patients (42.9%) following ocular trauma.[124] XFS was detected in a study of young amateur boxers.[125] How much the eye is indented around the limbus during ocular rubbing or ocular trauma? In acute blunt trauma, the damage is one time and severe, while with severe repetitive rubbing, the damage is cumulative progressive and infinitesimal. The eyeball is deformed with shortening of anteroposterior length and distension of the equatorial region, leading to stretch of the zonules [Figure 1]a and [Figure 1]b. Delori et al.[126] demonstrated in a pig eye model that blunt trauma causes indentation of the cornea with lens–cornea touch and backward displacement of the lens together with widening of the pars plana. This causes severe zonular stretching over several milliseconds [Figure 1]b. Second, there is compression of the angle, iris, ciliary body, anterior vitreous, lens over the area rubbed, resulting in squeezing injury to the zonules [Figure 2]a and [Figure 2]b. Third, XFS material can act as cutting fulcrum when eye is rubbed or traumatized. Note that flaccid cornea, or eyes with hypotony, or have more distortion of cornea and more indentation of the globe.{Figure 1}{Figure 2}

Delori et al.[126] used the technology of high-speed cinematography and single-flash high-speed photographs to document the globe deformation in 75 pig eyes immersed in gelatin, with high impact pellet to the center of the cornea. The distance between the posterior pole of the lens to the vitreous base elongated by 28% at 0.4 ms and shrank by 13% (from baseline) at 1 ms before resuming baseline level. If we extrapolate similar changes in humans, this deformation translates to sudden distension of the zonules by around 3 mm. The same applies after vigorous rubbing, but the distension of the zonules is slower and milder as witnessed by rubbing videos by volunteer on dynamic medical imaging (Investigating Eye Rubbing with Dynamic Medical Imaging, www.defeatkeratoconus.com). The equator of the vitreous base measures around 21 mm in normal eyes and expands by 28% or near 3.0 mm on either side of the zonules over a fraction of a millisecond in pellet or rub model. Superfast distension of the zonules leads to more breakage than gradual distension; hence, the breakage distension at high speed is estimated to be around 1 mm or so.[127]

Itching from atopy or dry eye is a trigger for chronic aggressive rubbing. Other causes of ocular rubbing include several disorders associated with an obsessive- compulsive form of ocular rubbing: Tourette syndrome,[128] Leber's congenital amaurosis, retinitis pigmentosa,[129] and the extreme form of the oculo-digital reflex also known as the pop-eye phenomenon.[130] To control chronic rubbing that may be the cause of XFS, there is a need for an increased vigilance and care of the eyes in XFS patients in the form of: education, meticulous therapy of ocular surface disease (preservative free antiallergic and lubricant, therapy of meibomian gland dysfunction or blepharitis), wearing of safety glasses, psychologic consultation or need for/ pharmacotherapy. Larger studies are needed to delineate the subset of XFS that relate to environmental factors.

Based on the above data [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], we propose that ocular rubbing [Figure 3] leads in susceptible eyes to keratoconus, iridoschisis, disruption of zonules, and partial tears of anterior capsule around zonules.[113],[131],[132],[133] Following severe rubbing, the intraocular pressure can rise to 100 mmHg[109] with collapse of peripheral anterior chamber, with the zonules becoming stretched or compressed by the posterior part of the iris, leading to tearing.{Figure 3}

The current study suffers from the shortcoming of any survey and from the small number of participants. However, the strength of the study includes near absence of nonresponse (high nonresponse rate can result in bias of the measures of outcome) and combining the current data with data from the systematic literature review, leading to a proposed comprehensive pathophysiology of XFS. Scientific evidence has shown that XFS is a multifactorial disease involving complex interaction of possible genetic and environmental factors. Our study and review of the literature point to a new factor (ocular rubbing) implicated in the pathogenesis of XFS and hence the need to better manage concurrent ocular surface disorder in these patients. Further studies with larger numbers of patients are needed to delineate more clearly the contribution of ocular rubbing, ocular surface disease, and other ocular or systemic or genetic factors [Table 5], [Table 6], [Table 7], [Table 8] to the development of XFS.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Nazarali S, Damji F, Damji KF. What have we learned about exfoliation syndrome since its discovery by John Lindberg 100 years ago? Br J Ophthalmol 2018;102:1342-50.
2Ritch R, Schlötzer-Schrehardt U. Exfoliation syndrome. Surv Ophthalmol 2001;45:265-315.
3Madden JG, Crowley MJ. Factors in the exfoliation syndrome. Br J Ophthalmol 1982;66:432-7.
4Ritch R. Systemic associations of pseudoexfoliatiion. Asia Pac J Ophthalmol 2016;5:45-50.
5John SW, Harder JM, Fingert JH, Anderson MG. Animal models of exfoliation syndrome, now and future. J Glaucoma 2014;23:S68-72.
6Yuan Y, Schlötzer-Schrehardt U, Ritch R, Call M, Chu FB, Dong F, et al. Transient expression of Wnt5a elicits ocular features of pseudoexfoliation syndrome in mice. PLoS One 2019;14:e0212569.
7Bernstein AM, Ritch R, Wolosin JM. Exfoliation syndrome: A disease of autophagy and LOXL1 proteopathy. J Glaucoma 2018;27 Suppl 1:S44-53.
8Ghaffari Sharaf M, Damji KF, Unsworth LD. Recent advances in risk factors associated with ocular exfoliation syndrome. Acta Ophthalmol 2020;98:113-20.
9Kang JH, Wiggs JL, Pasquale LR. Relation between time spent outdoors and exfoliation glaucoma or exfoliation glaucoma suspect. Am J Ophthalmol 2014;158:605-14.
10Jiwani AZ, Pasquale LR. Exfoliation syndrome and solar exposure: New epidemiological insights into the pathophysiology of the disease. Int Ophthalmol Clin 2015;55:13-22.
11Miglior S, Bertuzzi F. Exfoliative glaucoma: New evidence in the pathogenesis and treatment. Prog Brain Res 2015;221:233-41.
12Detorakis ET, Kozobolis VP, Pallikaris IG, Spandidos DA. Detection of herpes simplex virus in pseudoexfoliation syndrome and exfoliation glaucoma. Acta Ophthalmol Scand 2002;80:612-6.
13Teekhasaenee C, Suwan Y, Supakontanasan W, Tulvatana W, Ritch R. The clinical spectrum and a new theory of pathogenesis of true exfoliation syndrome. Ophthalmology 2016;123:2328-37.
14Akdemir MO, Kirgiz A, Ayar O, Kaldirim H, Mert M, Cabuk KS, et al. The effect of pseudoexfoliation and pseudoexfoliation induced dry eye on central corneal thickness. Curr Eye Res 2016;41:305-10.
15Kozobolis VP, Christodoulakis EV, Naoumidi II, Siganos CS, Detorakis ET, Pallikaris LG. Study of conjunctival goblet cell morphology and tear film stability in pseudoexfoliation syndrome. Graefes Arch Clin Exp Ophthalmol 2004;242:478-83.
16Kozobolis VP, Detorakis ET, Tsopakis GM, Pallikaris IG. Evaluation of tear secretion and tear film stability in pseudoexfoliation syndrome. Acta Ophthalmol Scand 1999;77:406-9.
17Öncel BA, Pinarci E, Akova YA. Tear osmolarity in unilateral pseudoexfoliation syndrome. Clin Exp Optom 2012;95:506-9.
18Rao A, Das G, Sarangi S, Padhy D. Conjunctival changes in different clinical variants of early pseudoexfoliation. Int Ophthalmol 2018;38:2477-85.
19Škegro I, Suić SP, Kordić R, Jandroković S, Petriček I, Kuzman T, et al. Ocular surface disease in pseudoexfoliation syndrome. Coll Antropol 2015;39:43-5.
20Noori S, Sati A, Moulick PS, Jaya K, Sandeep S, Rupali B, et al. Tear film abnormalities in pseudoexfoliation syndrome and normal healthy participants: A comparative analysis. Med J Armed Forces India 2020;76:303-6.
21Kaliaperumal S, Govindaraj I, Rao V. Abnormalities of tear function in patients with pseudoexfoliation. Int J Clin Exp Physiol 2014;1:34.
22Pujar C, Hiremath S, Gadag VR. Correlations between tear function abnormalities and pseudoexfoliation: A comparative study. Indian J Clin Exp Ophthalmol 2019;5:118-20.
23Potemkin VV, Ageeva EV. Pseudoexfoliation and meibomian gland dysfunction. Ophthalmol J 2016;9:52-7.
24Landers J, Henderson T, Craig J. Prevalence of pseudoexfoliation syndrome in indigenous Australians within central Australia: The Central Australian Ocular Health Study. Clin Exp Ophthalmol 2012;40:454-7.
25Resnikoff S, Filliard G, Dell'Aquila B. Climatic droplet keratopathy, exfoliation syndrome, and cataract. Br J Ophthalmol 1991;75:734-6.
26Forsius H, Forsman E, Fellman J, Eriksson AW. Exfoliation syndrome: Frequency, gender distribution and association with climatically induced alterations of the cornea and conjunctiva. Acta Ophthalmol Scand 2002;80:478-84.
27Yazgan S, Celik U, Alagöz N, Taş M. Corneal biomechanical comparison of pseudoexfoliation syndrome, pseudoexfoliative glaucoma and healthy subjects. Curr Eye Res 2015;40:470-5.
28Romero-Aroca P, Masip-Serra R, Martínez-Salcedo I, Salvat-Serra M, Fernández-Ballart J, Bautista-Pérez Á. High prevalence of pseudoexfoliation syndrome and its complications in Tarragona in northeast Spain. Eur J Ophthalmol 2011;21:580-8.
29Yenerel NM, Gorgun E, Kucumen RB, Oral D, Dinc UA, Ciftci F. Corneal biomechanical properties of patients with pseudoexfoliation syndrome. Cornea 2011;30:983-6.
30Palko JR, Qi O, Sheybani A. Corneal alterations associated with pseudoexfoliation syndrome and glaucoma: A literature review. J Ophthalmic Vis Res 2017;12:312-24.
31Topouzis F, Founti P, Yu F, Wilson MR, Coleman AL. Twelve-year incidence and baseline risk factors for pseudoexfoliation: The Thessaloniki eye study (an American Ophthalmological Society Thesis). Am J Ophthalmol 2019;206:192-214.
32Mccarty CA, Taylor HR. Pseudoexfoliation syndrome in Australian adults. Am J Ophthalmol 2000;129:629-33.
33Sorkou KN, Tsinopoulos IT, Tsaousis KT, Karamitsos A, Meditskou S, Ziakas N, et al. Ease of hydrodissection during phacoemulsification: A comparison between patients with and those without exfoliation syndrome. Ophthalmic Res 2020;63:497-500.
34Hietanen J, Kivelä T, Vesti E, Tarkkanen A. Exfoliation syndrome in patients scheduled for cataract surgery. Acta Ophthalmol (Copenh) 1992;70:440-6.
35Rotchford AP, Kirwan JF, Johnson GJ, Roux P. Exfoliation syndrome in black South Africans. Arch Ophthalmol 2003;121:863-70.
36Mitchell P, Wang JJ, Hourihan F. The relationship between glaucoma and pseudoexfoliation: The Blue Mountains Eye Study. Arch Ophthalmol 1999;117:1319-24.
37Forsman E, Cantor RM, Lu A, Eriksson A, Fellman J, Järvelä I, et al. Exfoliation syndrome: Prevalence and inheritance in a subisolate of the Finnish population. Acta Ophthalmol Scand 2007;85:500-7.
38Bikbov MM, Zainullin RM, Gilmanshin TR, Kazakbaeva GM, Yakupova DF, Nuriev IF, et al. Prevalence and associated factors of pseudoexfoliation in a Russian population: The ural eye and medical study. Am J Ophthalmol 2020;210:158-66.
39Kim S, Lim SH, Sung KR, Yun SC, Kim CY, Park KH, et al. Prevalence of pseudoexfoliation syndrome and associated factors in South Koreans: The Korean National Health and Nutrition Examination Survey. Ophthalmic Epidemiol 2016;23:298-302.
40Krishnadas R, Nirmalan PK, Ramakrishnan R, Thulasiraj RD, Katz J, Tielsch JM, et al. Pseudoexfoliation in a rural population of southern India: The Aravind Comprehensive Eye Survey. Am J Ophthalmol 2003;135:830-7.
41Jonas JB, Nangia V, Matin A, Bhojwani K, Sinha A, Khare A, et al. Pseudoexfoliation: Normative data and associations. The Central India Eye and Medical Study. PLoS One 2013;8:e76770.
42Arnarsson A, Jonasson F, Damji KF, Gottfredsdottir MS, Sverrisson T, Sasaki H. Exfoliation syndrome in the Reykjavik Eye Study: Risk factors for baseline prevalence and 5-year incidence. Br J Ophthalmol 2010;94:831-5.
43Pavičić-Astaloš J, Koluder A, Knežević L, Zorić Geber M, Novak-Lauš K, Csik T, et al. Prevalence of pseudoexfoliation syndrome and pseudoexfoliation glaucoma in population of North-West Croatia aged 40 and over. Acta Clin Croat 2016;55:483-9.
44You QS, Xu L, Wang YX, Yang H, Ma K, Li JJ, et al. Pseudoexfoliation: Normative data and associations: The Beijing eye study 2011. Ophthalmology 2013;120:1551-8.
45Hepsen IF, Yağci R, Keskin U. Corneal curvature and central corneal thickness in eyes with pseudoexfoliation syndrome. Can J Ophthalmol 2007;42:677-80.
46Berhanu YA, Giorgis AT, Alemu AM. Prevalence of ocular pseudoexfoliation in Baso and Worena District, Central Ethiopia. Ethiop J Health Dev 2020;34:54-8.
47Hiller R, Sperduto RD, Krueger DE. Pseudoexfoliation, intraocular pressure, and senile lens changes in a population-based survey. Arch Ophthalmol 1982;100:1080-2.
48Ekström C, Wilger S, Wanhainen A. Pseudoexfoliation and aortic aneurysm: A long-term follow-up study. Acta Ophthalmol 2019;97:80-3.
49Arnarsson A, Damji KF, Sverrisson T, Sasaki H, Jonasson F. Pseudoexfoliation in the Reykjavik Eye Study: Prevalence and related ophthalmological variables. Acta Ophthalmol Scand 2007;85:822-7.
50Yalaz M, Othman I, Nas K, Eroğlu A, Homurlu D, Cikintas Z, et al. The frequency of pseudoexfoliation syndrome in the eastern Mediterranean area of Turkey. Acta Ophthalmol (Copenh) 1992;70:209-13.
51Pasquale LR, Wiggs JL, Willett WC, Kang JH. The Relationship between caffeine and coffee consumption and exfoliation glaucoma or glaucoma suspect: A prospective study in two cohorts. Invest Ophthalmol Vis Sci 2012;53:6427-33.
52Tijani M, Albaroudi N, Boutimzine N, Cherkawi O, Laghmari M. Prévalence du syndrome exfoliatif et profil cardiovasculaire des patients programmés pour chirurgie de cataracte. J Fr Ophtalmol 2017;40:623-8.
53Pasquale LR, Jiwani AZ, Zehavi-Dorin T, Majd A, Rhee DJ, Chen T, et al. Solar exposure and residential geographic history in relation to exfoliation syndrome in the United States and Israel. JAMA Ophthalmol 2014;132:1439-45.
54Arakaki Y, Sawaguchi S, Iwase A, Tomidokoro A, Araie M. Pseudoexfoliation syndrome and relating factors in a rural Japanese population: The Kumejima Study. Acta Ophthalmol 2020;98:e888-e894.
55Wirostko BM, Curtin K, Ritch R, Thomas S, Allen-Brady K, Smith KR, et al. Risk for exfoliation syndrome in women with pelvic organ prolapse: A Utah Project on Exfoliation Syndrome (UPEXS) Study. JAMA Ophthalmol 2016;134:1255-62.
56Besch BM, Curtin K, Ritch R, Allingham RR, Wirostko BM. Association of exfoliation syndrome with risk of indirect inguinal hernia: The Utah Project on Exfoliation Syndrome. JAMA Ophthalmol 2018;136:1368-74.
57Sorkhabi R, Ghorbanihaghjo A, Ahoor M, Nahaei M, Rashtchizadeh N. High-sensitivity C-reactive protein and tumor necrosis factor alpha in pseudoexfoliation syndrome. Oman Med J 2013;28:16-9.
58Dursun F, Vural Ozec A, Aydin H, Topalkara A, Dursun A, Toker MI, et al. Total oxidative stress, paraoxonase and arylesterase levels at patients with pseudoexfoliation syndrome and pseudoexfoliative glaucoma. Int J Ophthalmol 2015;8:985-90.
59Yazdani S, Tousi A, Pakravan M, Faghihi AR. Sensorineural hearing loss in pseudoexfoliation syndrome. Ophthalmology 2008;115:425-9.
60Papadopoulos TA, Charalabopoulou M, Vathylakis I, Goumas P, Gartaganis S, Naxakis S. Prevalence and severity of sensorineural hearing loss in patients with exfoliation syndrome. Eur Rev Med Pharmacol Sci 2012;16:902-7.
61Sarenac-Vulovic TS, Mirjana A, Janicijevic Petrovic MA, et al. Systemic manifestations of pseudoexfoliation. Ser J Exp Clin Res 2014;15:29-32.
62Singham NV, Zahari M, Peyman M, Prepageran N, Subrayan V. Association between ocular pseudoexfoliation and sensorineural hearing loss. J Ophthalmol 2014;2014:825936.
63Cumurcu T, Dorak F, Cumurcu BE, Erbay LG, Ozsoy E. Is there any relation between pseudoexfoliation syndrome and Alzheimer's type dementia? Semin Ophthalmol 2013;28:224-9.
64Linnér E, Popovic V, Gottfries CG, Jonsson M, Sjögren M, Wallin A. The exfoliation syndrome in cognitive impairment of cerebrovascular or Alzheimer's type. Acta Ophthalmol Scand 2001;79:283-5.
65Turgut Coban D, Cakir T, Erol MK, Dogan G, Dogan B, Bilgilisoy Filiz M, et al. Electroneuromyographic findings in pseudoexfoliation syndrome. Int Ophthalmol 2018;38:705-12.
66Batur M, Seven E, Tanrıkulu M, Ekin S, Tekin S, Yasar T. Pulmonary functions in pseudoexfoliation syndrome. Clin Respir J 2018;12:2271-6.
67Yaşar E, Yıldırım N, Atalay E. Pseudoexfoliation syndrome and antidepressant drug use. Turk J Ophthalmol 2019;49:1-5.
68Cumurcu T, Cumurcu BE, Celikel FC, Etikan I. Depression and anxiety in patients with pseudoexfoliative glaucoma. Gen Hosp Psychiatry 2006;28:509-15.
69Scharfenberg E, Rauscher FG, Meier P, Hasenclever D. Pseudoexfoliation syndrome: Analysis of systemic comorbidities of 325 PEX-positive patients compared with 911 PEX-negative patients. Graefes Arch Clin Exp Ophthalmol 2019;257:2471-80.
70Gokce SE, Gokce MI. Relationship between pseudoexfoliation syndrome and erectile dysfunction: A possible cause of endothelial dysfunction for development of erectile dysfunction. Int Braz J Urol 2015;41:547-51.
71Vardhan SA, Haripriya A, Ratukondla B, Ramulu P, Shivakumar C, Nath M, et al. Association of Pseudoexfoliation With Systemic Vascular Diseases in a South Indian Population. JAMA Ophthalmol 2017;135:348-54.
72Alpaslan M, Karalezli A, Borazan M, Köktekir BE, Müderrisoğlu IH. Decreased aortic root elasticity-as a novel systemic manifestation of the pseudoexfoliation syndrome: An observational study. Anadolu Kardiyol Derg 2012;12:483-7.
73Yüksel N, Anik Y, Kiliç A, Karabaş V, Demirci A, Cağlar Y. Cerebrovascular blood flow velocities in pseudoexfoliation. Graefes Arch Clin Exp Ophthalmol 2006;244:316-21.
74Yüksel N, Anik Y, Altintaş O, Onur I, Cağlar Y, Demirci A. Magnetic resonance imaging of the brain in patients with pseudoexfoliation syndrome and glaucoma. Ophthalmologica 2006;220:125-30.
75Kocabeyoglu S, Mocan MC, Irkec M, Pinar A, Bozkurt B, Orhan M. Serum vitamin D deficiency and its association with systemic disease in exfoliation syndrome. Eur J Ophthalmol 2013;23:526-31.
76Kan E, Yılmaz A, Demirağ MD, Çalık M. Is Pseudoexfoliation Syndrome a Risk Factor for Cerebro Vascular Disease? Semin Ophthalmol 2017;32:153-6.
77Chung H, Arora S, Damji KF, Weis E. Association of pseudoexfoliation syndrome with cardiovascular and cerebrovascular disease: A systematic review and meta-analysis. Can J Ophthalmol 2018;53:365-72.
78Rumelaitienė U, Žaliūnienė D, Špečkauskas M, Tamošiūnas A, Radišauskas R, Jusevičiūtė E, et al. Link of ocular pseudoexfoliation syndrome and vascular system changes: Results from 10-year follow-up study. Int Ophthalmol 2020;40:957-66.
79Djordjevic-Jocic J, Jovanovic P, Bozic M, Tasic A, Rancic Z. Prevalence and early detection of abdominal aortic aneurysm in pseudoexfoliation syndrome and pseudoexfoliation glaucoma. Curr Eye Res 2012;37:617-23.
80Sarenac Vulovic TS, Pavlovic SM, Jakovljevic VLj, Janicijevic KB, Zdravkovic NS. Nitric oxide and tumour necrosis factor alpha in the process of pseudoexfoliation glaucoma. Int J Ophthalmol 2016;9:1138-42.
81Wang W, He M, Zhou M, Zhang X. Ocular pseudoexfoliation syndrome and vascular disease: A systematic review and meta-analysis. PLoS One 2014;9:e92767.
82Yüksel B, Schlötzer-Schrehardt U, Pehlivan O, Topaloglu E. A 13-year-old girl with presumed pseudoexfoliation. Acta Ophthalmol Scand 2005;83:626-7.
83Konstas AG, Ritch R, Bufidis T, Morales J, Qi Y, Streeten BW. Exfoliation syndrome in a 17-year-old girl. Arch Ophthalmol 1997;115:1063-7.
84Küchle M, Naumann GO. Occurrence of pseudoexfoliation following penetrating keratoplasty for keratoconus. Br J Ophthalmol 1992;76:98-100.
85Horven I, Hutchinson BT. Exfoliation syndrome. Case reports of 31 and 35-year-old patients. Acta Ophthalmol (Copenh) 1967;45:294-8.
86Konstas AG, Williamson TH. Coexistence of exfoliation syndrome, previous iris surgery and heterochromia. Acta Ophthalmol Scand 1992;112:850-2.
87Sampaolesi R, Casiraghi JF, Geria R. The occurrence of exfoliation syndrome after penetrating keratoplasty: A report of three cases. Klin Monatsbl Augenheilkd 1995;206:8-9.
88Sugar HS, Harding C, Barsky D. The exfoliation syndrome. Ann Ophthalmol 1976;8:1165-81.
89Fakhraie G, Mohammadi M, Moghimi S. Unilateral pseudoexfoliation in two young patients with history of iris trauma and associated intraocular surgery. Iran J Ophthalmol 2012;24:57-60.
90Amini H, Daneshvar R, Eslami Y, Moghimi S, Amini N. Early-onset pseudoexfoliation syndrome following multiple intraocular procedures. J Ophthalmic Vis Res 2012;7:190-6.
91Kumar PS, Rao A, Senthil S. Premature expression of pseudoexfoliation syndrome with presenile cataract in a 28-year-old lady. J Glaucoma 2019;28:e115-7.
92Bartholomew RS. Pseudo-capsular exfoliation in the Bantu of South Africa. I. Early or pre-granular clinical stage. Br J Ophthalmol 1971;55:693-9.
93Tarkkanen A. Pseudoexfoliation of the lens capsule. A clinical study of 418 patients with special reference to glaucoma, cataract, and changes of the vitreous. Acta Ophthalmol Suppl 1962;Suppl 71:1-98.
94Taylor HR, Hollows FC, Moran D. Pseudoexfoliation of the lens in Australian aborigines. Br J Ophthalmol 1977;61:473-5.
95Summanen P, Tönjum AM. Exfoliation syndrome among Saudis. Acta Ophthalmol Suppl 1988;184:107-11.
96Khanzada AM. Exfoliation syndrome in Pakistan. Pakistan J Ophthalmol 1985;2:7-9.
97Joannides T, Katsourakis N, Velissaropoulos P. Glaucoma capsulare. Ophthalmologica 1961;142:160-89.
98Als E. Lens exfoliation and related and related problems in Iceland. Nordic Counc Arct Med Res Rep 1980;26:48-53.
99Oliveira C, Schlötzer-Schrehardt U, Vieira G, Liebmann J, Ritch R. Early diagnosis of exfoliation syndrome in the offspring of affected patients. Acta Ophthalmol Scand 2006;84:512-5.
100McKay KM, Borkar DS, Moustafa GA, Haviland MJ, Kloek CE, PCIOL Study Group. Clinical factors affecting operating room utilization in cataract surgery: Results from the PCIOL study. J Cataract Refract Surg 2020;46:14-9.
101Erdoğan H, Arici DS, Toker MI, Arici MK, Fariz G, Topalkara A. Conjunctival impression cytology in pseudoexfoliative glaucoma and pseudoexfoliation syndrome. Clin Exp Ophthalmol 2006;34:108-13.
102Küchle M, Schlötzer-Schrehardt U, Naumann GO. Occurrence of pseudoexfoliative material in parabulbar structures in pseudoexfoliation syndrome. Acta Ophthalmol (Copenh) 1991;69:124-30.
103Ringvold A. On the occurrence of pseudoexfoliation material in extrabulbar tissue from patients with pseudoexfolation syndrome of the eye. Acta Ophthalmol 1973;51:411-8.
104Joachim SC, Wuenschig D, Pfeiffer N, Grus FH. IgG antibody patterns in aqueous humor of patients with primary open angle glaucoma and pseudoexfoliation glaucoma. Mol Vis 2007;13:1573-9.
105Smoleńska-Janicowa D, Bernacka K. Relationship between exfoliation syndrome and autoimmunity. Results of the analysis of aqueous humor. Klin Oczna 1982;84:99-100.
106Laatikainen L. Fluorescein angiographic studies of the 7 peripapillary and perilimbal regions in simple, capsular and 8 low-tension glaucoma. Acta Ophthalmol 1971;111Suppl:3-83.
107Henriquez MA, Cerrate M, Hadid MG, Cañola-Ramirez LA, Hafezi F, Izquierdo L Jr., et al. Comparison of eye-rubbing effect in keratoconic eyes and healthy eyes using Scheimpflug analysis and a dynamic bidirectional applanation device. J Cataract Refract Surg 2019;45:1156-62.
108Mansour AM, Haddad RS. Corneal topography after ocular rubbing. Cornea 2002;21:756-8.
109Turner DC, Girkin CA, Downs JC. The magnitude of intraocular pressure elevation associated with eye rubbing. Ophthalmology 2019;126:171-2.
110Osuagwu UL, Alanazi SA. Eye rubbing-induced changes in intraocular pressure and corneal thickness measured at five locations, in subjects with ocular allergy. Int J Ophthalmol 2015;8:81-8.
111McMonnies CW. Abnormal rubbing and keratectasia. Eye Contact Lens 2007;33:265-71.
112Moran S, Gomez L, Zuber K, Gatinel D. A case-control study of keratoconus risk factors. Cornea 2020;39:697-701.
113Ben-Eli H, Erdinest N, Solomon A. Pathogenesis and complications of chronic eye rubbing in ocular allergy. Curr Opin Allergy Clin Immunol 2019;19:526-34.
114Nagaki Y, Hayasaka S, Kadoi C. Cataract progression in patients with atopic dermatitis. J Cataract Refract Surg 1999;25:96-9.
115Pecora L, Sibony P, Fourman S. Eye-rubbing optic neuropathy. Am J Ophthalmol 2002;134:460-1.
116Kothari N, Young RC, Read SP, Tutiven J, Perez VL, Flynn HW Jr., et al. Retinal detachment associated with atopic dermatitis. Ophthalmic Surg Lasers Imaging Retina 2017;48:513-7.
117Bozkurt B, Yılmaz M, Meşen A, Kamış Ü, Ekinci Köktekir B, Okudan S. Correlation of corneal endothelial cell density with corneal tomographic parameters in eyes with keratoconus. Turk J Ophthalmol 2017;47:255-60.
118Mocan MC, Yilmaz PT, Irkec M, Orhan M. In vivo confocal microscopy for the evaluation of corneal microstructure in keratoconus. Curr Eye Res 2008;33:933-9.
119De Maria A, Wilmarth PA, David LL, Bassnett S. Proteomic analysis of the bovine and human ciliary zonule. Invest Ophthalmol Vis Sci 2017;58:573-85.
120Assia EI, Apple DJ, Morgan RC, Legler UF, Brown SJ. The relationship between the stretching capability of the anterior capsule and zonules. Invest Ophthalmol Vis Sci 1991;32:2835-9.
121Saber HR, Butler TJ, Cottrell DG. Resistance of the human posterior lens capsule and zonules to disruption. J Cataract Refract Surg 1998;24:536-42.
122Guo S, Gewirtz M, Thaker R, Reed M. Characterizing pseudoexfoliation syndrome through the use of ultrasound biomicroscopy. J Cataract Refract Surg 2006;32:614-7.
123Ritch R, Vessani RM, Tran HV, Ishikawa H, Tello C, Liebmann JM. Ultrasound biomicroscopic assessment of zonular appearance in exfoliation syndrome. Acta Ophthalmol Scand 2007;85:495-9.
124McWhae JA, Crichton AC, Rinke M. Ultrasound biomicroscopy for the assessmentof zonules after ocular trauma. Ophthalmology 2003;110:1340-3.
125Kagmeni G, Nguefack-Tsague G, Ebana Mvogo SR, Ebana Mvogo C. Ophthalmological findings in Cameroonian boxers. Clin Ophthalmol 2017;11:1121-6.
126Delori F, Pomerantzeff O, Cox MS. Deformation of the globe under high-speed impact: It relation to contusion injuries. Invest Ophthalmol 1969;8:290-301.
127Knudson DV. The biomechanics of stretching. J Exerc Sci Physiother 2006;2:3-12.
128Shinzawa M, Kato N, Kasai K, Konomi K, Chai Y, Shimazaki J. Corneal cross-linking for keratoconus caused by compulsive eye rubbing in patients with Tourette syndrome: Three case reports. Medicine (Baltimore) 2019;98:e15658.
129Dikopf MS, Chow CC, Mieler WF, Tu EY. Cataract extraction outcomes and the prevalence of zonular insufficiency in retinitis pigmentosa. Am J Ophthalmol 2013;156:82-800.
130Mansour AM, Reinecke RD. The pop-eye phenomenon: An extreme form of the oculodigital reflex. J Clin Neuroophthalmol 1985;5:281-2.
131Yusuf IH, Salmon JF. Iridoschisis and keratoconus in a patient with severe allergic eye disease and compulsive eye rubbing: A case report. J Med Case Rep 2016;10:134.
132Eiferman RA, Law M, Lane L. Iridoschisis and keratoconus. Cornea 1994;13:78-9.
133Krohn DL, Garrett EE. Iridoschisis and keratoconus; report of case in a twenty-year-old man. AMA Arch Ophthalmol 1954;52:426-32.