Prevalence and Clinical Associations of Relative Anterior Microphthalmos assessed with an Optical Biometer

doi:10.21203/rs.3.rs-4725620/v1

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Prevalence and Clinical Associations of Relative Anterior Microphthalmos assessed with an Optical Biometer

https://doi.org/10.21203/rs.3.rs-4725620/v1

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Background/Objective:

Relative anterior microphthalmos (RAM) is a rare ocular condition characterized by disproportionately small anterior segments but normal axial length (corneal diameter < 11 mm and axial length > 20 mm). This study aimed to determine the prevalence of RAM and its association with glaucoma utilizing IOL Master 700 data (Carl Zeiss Meditec, Jena, Germany).

Subject/Methods:

A retrospective analysis was conducted of the biometric parameters of 6,407 eyes, and 115 cases of RAM were identified. The incidence of glaucoma was assessed, together with the outcomes of cataract surgery in cases of RAM with glaucoma.

Results

RAM prevalence was 1.8%. RAM patients had a higher incidence of glaucoma (26.1%), notably of the angle-closure subtype. Cataract surgery significantly reduced intraocular pressure in cases of RAM with glaucoma; however, RAM patients experienced a higher rate of surgical complications.

Conclusion

RAM poses clinical challenges due to its association with glaucoma and increased surgical risks. This study emphasizes the importance of advanced diagnostic tools such as the IOL Master in tailoring interventions to optimize patient outcomes.

Small eye spectrum is a type of eye derangement resulting from developmental arrests during embryogenesis. Although uncommon, it can cause serious ophthalmic issues, ranging from developmental visual problems to frequent occurrences of associated conditions such as glaucoma and some surgery-related complications following refractive correction and cataract surgery.(1, 2) There are diverse “small eye” variants, ranging from pan-ocular size reduction, such as nanophthalmos and microphthalmos, to disproportionate smallness of specific parts of the eye, either in the anterior or posterior segment, such as relative anterior microphthalmos (RAM) and posterior microphthalmos (PM).(3)

The term relative anterior microphthalmos was first used by Naumann in 1980 to define an eye with normal axial length (≥ 21 mm) but disproportionately smaller anterior segment (corneal diameter ≤ 11 mm).(4) Auffarth et al. conducted a study of 2000 patients with RAM morphometry and characterized RAM as an eye with horizontal corneal diameters ≤ 11 mm, axial length of > 20 mm, but no other morphologic malformations.(5) These characteristics have resulted in increased surgical difficulty and complications, including postoperative transient corneal edema (up to 75%), uveal inflammation (12%) associated with surgical trauma and presence of small pupil, Descemet’s membrane detachment (5.95%), and posterior capsule ruptures (2.38%).(6) Over the years, there has been a scarcity of studies focused on this condition, leading to its potential damage being overlooked, especially with regard to its association with glaucoma and related management.

In recent years, there has been a shift in the standard measurement of intraocular lens (IOL) power calculation for cataract patients from the ultrasonic biometry (A-scan) to non-contact optical biometry. This change eliminates ocular discomfort associated with the contact A-scan technique, whether through applanation or immersion, and is a more convenient method.(7, 8) IOL Master (Carl Zeiss Meditec, Jena, Germany) applies a non-contact coherence inferred diode laser via partial coherence interferometry to measure particular ocular parameters such as keratometry (K), lens thickness (LT), anterior chamber depth (ACD), and axial length (AL).(9) This advancement has allowed us to measure ocular parameters accurately. Digital collection of all pertinent data over an extended period is potentially beneficial for research.(10, 11)

The current study utilized automated devices (in particular the IOL Master) alongside optical biometry to determine the prevalence of RAM and analyze its correlation with various subtypes of glaucoma. Additionally, we investigated cataract surgery and its complications in RAM patients. This study aims to provide valuable insights into the clinical importance of RAM in both glaucoma and cataract surgery, with the potential to shape tailored treatment approaches for individuals managing both conditions concurrently.

A retrospective study of RAM identified with IOL Master was conducted in the tertiary eye care centre of Rajavithi Hospital, Bangkok, Thailand. The research protocol was approved by the hospital’s Ethics Committee (Document number 151/2022), and the study was performed between December 2022 and December 2023, following all of the guidelines for experimental investigation in human subjects required by the Ethics Committee, with informed consent secured from every subject. All investigations were carried out in accordance with the Declaration of Helsinki.

Inclusion criteria were cataract patients requiring lens removal and IOL implantation who underwent IOL Master700 scanning by experienced technicians. Exclusion criteria were patients who had opaque optical media, dense cataract, anterior and/or posterior segment diseases such as corneal scar, advanced pterygium, proliferative diabetic retinopathy, or maculopathy. Participants were also excluded if they had any previous history of eye injury; ocular surgery, such as refractive surgery, cataract, glaucoma (trabeculectomy and/or glaucoma tube shunt); or vitreoretinal surgery.

Ocular parameters, including anterior chamber depth (ACD), lens thickness (LT), total axial length (AL), and white to white (WTW), were assessed by the biometer. Raw data from the IOL Master 700, comprising 15,727 entries, was initially exported to an MS Excel spreadsheet. Following deidentification, pseudophakic eyes and those with inaccurate or unsuccessful measurements were excluded from the dataset. This left a total of 4,385 patients with accurate axial length (AL) and white-to-white (WTW) measurements, corresponding to 8,267 eyes. After eliminating duplicate entries, the final dataset consisted of 4,163 patients, leaving 6,407 eyes for analysis.

Definition of RAM

RAM is defined when ocular parameters from IOL Master 700 measurement meet all of the following criteria:

White to white \(\:\le\:\) 11mm (5, 6, 12)
Axial length > 20 mm
No other detected ocular malformation

Definition of glaucoma

Primary open-angle glaucoma is defined as an eye with glaucomatous optic neuropathy with or without visual field defect, gonioscopic open angle, and IOP > 21 mmHg. Normal-tension glaucoma is defined as POAG with IOP ≤ 21 mmHg.

Primary angle-closure disease (PACD) included primary angle-closure suspect (PACS), primary angle-closure (PAC), and primary angle-closure glaucoma (PACG) as classified by Foster et al.(13) PACS was defined as Shaffer’s gonioscopic grading ≤ 2 in at least 2 quadrants, with normal IOP and without glaucomatous optic disc and visual field defect; PAC was classified as PACS with IOP > 21 mmHg, presence of PAS and without any glaucomatous changes; and PACG was defined as PAC with glaucomatous changes.

Using retrospective chart review, data of the RAM group were extracted, including biographic data, measured ocular parameters, and other associated ocular conditions such as corneal guttata and glaucoma. For patients who underwent cataract surgery, we collected additional information such as age, sex, preoperative and postoperative intraocular pressure (IOP), and antiglaucoma medication usage, as well as surgical complications.

Glaucoma-related parameters were taken from the 3 months preceding the date of IOL Master measurement. If there were more than 2 values, we choose the most recent one prior to IOL measurement. Intraocular pressure measurements were performed using Goldmann applanation if it was accessible. Preoperative data were extracted from the latest outpatient department visit to the surgery day or admission day, while postoperative data were collected during the 1-month postoperative period. Surgeons were categorized as senior (ophthalmologists with more than 5 years of experience) and junior (resident, fellow or ophthalmologists with 1 to 5 years of experience). Additionally, complications from surgery and their potential associated risks were evaluated. Corneal decompensation, suprachoroidal hemorrhage, retinal detachment, and endophthalmitis were considered to be serious surgical complications. (14, 15)

Statistical analysis

Statistical analysis was performed with SPSS software version 28 (SPSS Inc., Chicago, IL, USA). Continuous variables (ocular parameters, age, IOP, and number of medications) were reported as mean with standard deviation while categorical variables (gender, type of glaucoma, presence of corneal guttata) were presented as percentages. Differences in ocular parameters in two different groups were assessed by independent T-test and Mann-Whitney U Test. Paired Sample T-test was used to evaluate the change in IOP and the number of medications needed before and after cataract surgery. Factors associated with complication risk were calculated using logistic regression analysis and presented as Odds Ratio (OR). P values \(\:\le\:\) 0.05 were considered to be statistically significant.

Out of the 6,407 eyes of 4,163 patients, 115 eyes of 105 patients met the criteria for RAM, indicating a prevalence of 1.8% (115 from 6,407 eyes). Eighty-one cases (77.14%) were female, and 21 (17.4%) were bilateral.

Regarding eyewise analysis, 3 of 115 eyes had corneal guttata (2.6%), and one of these cases developed corneal decompensation after cataract surgery. Glaucoma was recorded in 30 eyes (26.09%). Detailed demographic data of patients with RAM are presented in Table 1.

Table 1

Demographic data in RAM patients
	105 patients 115 eyes (%)
Mean Age ± SD;yrs (N = 105 patients)	65.21 ± 10.45 years (23–81 years)
Laterality (N = 105)
Bilateral	20(17.39%)
Unilateral	95(82.61%)
Gender (N = 105)
Female	81(77.14%)
Male	24(22.86%)
Corneal guttata (N = 115 eyes)	3(2.6%)
Glaucoma (N = 115 eyes)	30(26.09%)
Primary angle closure disease	20(17.39%)
Primary open-angle glaucoma	7(6.09%)
Secondary glaucoma	2(1.74%)
Normal tension glaucoma	1(0.87%)

Among the glaucoma patients, females were predominantly affected, with 22 eyes in 20 females, while males accounted for only 8 cases. The most frequently encountered type of glaucoma was PACD, succeeded by POAG, secondary glaucoma, and NTG. Nineteen eyes (16.67%) with RAM presented with acute angle-closure crisis (AACC), and 15 (10%) were identified as fellow eyes following a previous AACC attack.

Glaucoma surgery was performed on 6 eyes, involving 1 use of phacoemulsification with intraocular lens implantation (PE-IOL) with goniosynechialysis (PE-GSL) and 5 of trabeculectomy. Laser peripheral iridotomy was performed in 17 eyes with RAM: 9 with PACG, 7 with PAC, and 1 with neovascular glaucoma (NVG).

A comparative analysis of ocular parameters between individuals with and without relative anterior microphthalmos (RAM) revealed significant disparities. In a study comprising 115 eyes with RAM and 6291 without it, median values (interquartile range) were scrutinized for various parameters. RAM eyes, defined by a WTW measurement of ≤ 11 mm and an AL exceeding 20 mm, exhibited notably shallower ACD, shorter AL, and slightly thicker lens compared to non-RAM eyes; however, there was no statistically significant difference between CCT in the two groups. Furthermore, RAM eyes displayed a higher lens-axial length factor (LAF) than non-RAM eyes (2.14 vs. 1.96, p < 0.01). Detailed findings are presented in Table 2. Notably, among the eyes with RAM, 23 (20%) exhibited a LAF greater than 2.3.(ref. 16)

Table 2

"Comparative Analysis of Ocular Parameters Using IOL Master: Relative Anterior Microphthalmos vs. Non-relative Anterior Microphthalmos"
Ocular parameters	RAM eyes N = 115 eyes Median (interquartile range)	Non-RAM eyes N = 6291 eyes Median (interquartile range)	P value^†
White-to-white (mm)	10.87 (0.20)	11.91 (0.58)	p < 0.001
Anterior chamber depth (mm)	2.57 (0.62)	3.08 (0.58)	p < 0.001
Axial length (mm)	22.35 (1.09)	23.48 (1.34)	p < 0.001
Lens thickness (mm)	4.75 (0.60)	4.62 (0.62)	p < 0.001
Central corneal thickness (µm)	529.82 (39.34)	531.60 (46.53)	P = 0.513
Lens-axial length factor	2.14 (0.31)	1.96 (0.33)	p < 0.001

†Mann-Whitney U Test

From baseline data in RAM, the mean IOP was 23.43 ± 12.71 mmHg, ranging from 6 to 52 mmHg. The vertical cup-disc ratio was 0.74 ± 0.18, varying from 0.3 to 1.0. On average, patients were using 2.7 ± 1.46 IOP-lowering medications, with the number of medications ranging from 0 to 5.

A comparative analysis of RAM with and without glaucoma is shown in Table 3. ACD and WTW in the glaucoma group was significantly lower than in the non-glaucoma patients.

Table 3

Biometric parameters comparing RAM patents with and without glaucoma
Parameters	RAM with glaucoma (N = 30 eyes) Mean ± SD	RAM without glaucoma (N = 85 eyes) Mean ± SD	P value
Anterior chamber depth (mm)	2.36 ± 0.38	2.72 ± 0.39	< 0.001^¶
Axial length (mm)	22.18 ± 0.94	22.65 ± 1.49	0.109^¶
White-to-white (mm)	10.72 ± 0.24	10.84 ± 0.23	0.017^†
Lens thickness (mm)	4.84 ± 0.37	4.72 ± 0.52	0.302^¶
Central corneal thickness (µm)	534.48 ± 37.63	532.13 ± 33.18	0.803^†
Lens-axial length factor	2.18 ± 0.18	2.07 ± 0.36	0.115^¶

¶Independent Sample T-test

†Mann-Whitney U Test

Cataract surgery and its complications in RAM

Forty-four eyes in the RAM group underwent cataract removal by multiple surgeons, either senior (24 eyes) or junior ophthalmologists (20 eyes). The procedures encompassed different types of cataract surgery: 9 underwent PE-IOL; 7 received PE-GSL; 1 had PE combined with trabeculectomy; 4 underwent PE with pars plana vitrectomy; and 3 extracapsular cataract extractions (ECCE) were performed.

• IOP reduction and number of IOP-lowering medications

Cataract surgery resulted in a notable reduction in intraocular pressure (IOP), with a mean preoperative IOP of 18.11 ± 7.82 mmHg decreasing to 14.42 ± 3.26 mmHg postoperatively (p = 0.004). Specifically, in the subgroup of patients with coexisting glaucoma, there was a significant decrease in IOP from 22.47 ± 11.70 mmHg before surgery to 13.40 ± 3.46 mmHg afterwards (p = 0.009). Additionally, surgery led to a significant decrease in the number of IOP-lowering medications required, dropping from 1.07 ± 1.634 preoperatively to 0.48 ± 1.0 at one month postoperatively (p < 0.001).

• Surgical complications

Among the 44 eyes with RAM that underwent cataract surgery, a total of 18 complications (40.9%) were observed. These included 14 cases of corneal edema at 1-week post-surgery, 1 posterior capsule rupture, 1 hyphema, 1 retained lens cortex, and 1 case of corneal decompensation, which was identified as the only serious complication in our study. Comparing biometric parameters in cases with and without complications, we found statistically significant differences between ACD and LAF in these groups: ACD in cases with complications was significantly shallower (mean 2.34 ± 0.41 mm vs 2.62 ± 0.35 mm, p = 0.023) and LAF was significantly higher (2.23 ± 0.20 vs 2.07 ± 0.26, p = 0.05). No other sight-threatening complications (such as expulsive choroidal hemorrhage or endophthalmitis) occurred.

Several risk factors were identified in association with surgical complications. An ACD of ≤ 2.2 mm (p = 0.023), LAF ≥ 2.3 (p = 0.030), and the involvement of a junior surgeon (p = 0.011) were pinpointed as significant contributors, elevating the likelihood of complications by 5.5, 5.8, and 6.1 times respectively. Interestingly, glaucoma and gender did not exhibit any discernible risk based on crude odds ratios in our analysis. (see Table 4)

Table 4

Logistic Regression Analysis: Risk Factors Associated with Surgical Complications
Risk factors	Unadjusted OR	95% CI	P-value	Adjusted OR	95% CI	P-value
Gender	6.30	0.72–55.51	0.097	-	-	-
anterior chamber depth (ACD)*	5.47	1.27–23.64	0.023	9.46	1.33–67.51	0.025
lens-axial length factor (LAF)**	5.78	1.19–28.04	0.030	21.08	1.76-252.51	0.016
Junior surgeon	6.11	1.52–24.50	0.011	26.82	2.46-292.63	0.007
Glaucoma	3.00	0.82–11.02	0.098	-	-	-
ACD = less than 2.2 mm., *LAF ≥ 2.3

In this clinical study of RAM, a large dataset of 6,407 eyes was investigated. We identified a lower prevalence of RAM in Thai patients than found in a previous study of Indian people (1.8% versus 6%). This difference in prevalence could stem from various factors, including type of measurement technique used. Nihalani et al. employed manual calipers and A-scan ultrasound to determine RAM, whereas we utilised an optical biometer for measurement, and this may have resulted in variations in parameter values. (6) For instance, Ang et al. and Baumeister et al. revealed that the IOL Master generally produced larger WTW values than those identified using calipers (12.14 vs. 11.45 and 12.02 vs. 11.91 mm respectively). (17, 18) Anterior chamber depth and AL can also exhibit discrepancies. Two studies conducted in the same country have shown contrasting results: one demonstrated differing ACD values obtained by the IOL Master and ultrasound in both normal and short eye groups, with the IOL Master tending to yield shallower ACD measurements (19), while the other found that the IOL Master obtained deeper ACD measurements than ultrasound (20). Additionally, some studies have shown significantly longer AL values measured by the IOL Master than those found using ultrasound, while other research has found no significant difference.(21–24) With the newer technology of the ocular biometry that we used, we believe that the prevalence of RAM in the present study is more accurate than previously reported.

In addition, differences in study populations and demographics, such as our focus on a Southeast Asian population compared to studies examining populations from South Asia, may contribute to variations in reported prevalence rates. While there has so far been no direct head-to-head comparison in terms of this parameter, based on our latest understanding, we believe there is a high potential for such differences to exist.(25) Factors such as genetic predispositions, environmental influences, and socioeconomic factors specific to each population could influence the prevalence rates of conditions like relative anterior microphthalmos. Further research focusing on comparative studies across different populations with this optical biometer could provide valuable insights into these potential variations.

Microphthalmos manifests either as a unilateral or bilateral disease and may be associated with other ocular deformations such as coloboma, or persistent hyperplastic primary vitreous. Fahnehjelm et al. reported that 26 of 35 (74.3%) instances of anophthalmos/microphthalmos were unilateral.(26) In the present study, RAM presented as a unilateral disease in 82.6% of cases, while 17.4% were bilateral. There was no association with ocular coloboma in those 115 RAM eyes.

Glaucoma association

Our findings reveal a remarkably higher rate of glaucoma within the RAM group compared to that of the general population, 26.1%, vs. 3.54% respectively.(27, 28) Focusing on the closed-angle subtype, it is noteworthy that RAM patients exhibited a higher incidence, with 6.9% of RAM cases presenting with acute angle-closure attacks, whether in the RAM eye or fellow eyes. This incidence is higher than that in the general population in Asia, which typically ranges from 6 to 12 per 100,000. (29, 30) The increased occurrence can be attributed to shallower ACD and a higher LAF in RAM eyes. This raises concerns regarding access to the angle by gonioscopy technique or earlier laser iridotomy in high-risk patients, as indicated by data from the IOL Master. This finding is corroborated by the fact that 16 out of 115 RAM cases necessitated laser peripheral iridotomy based on clinical indications. Consequently, given the significant IOP reduction following cataract extraction, this procedure may also be considered the best treatment for lowering IOP in RAM. Notably, 20% (6 out of 30) of glaucoma cases require glaucoma surgical intervention due to maximally tolerated medical treatment, indicating a higher severity and the necessity for vigilant monitoring.

Cataract surgery-related complication

In Table 5, we compared surgical complications between our study and the previous one by Nihalani et al.(6) While the prior study reported a higher incidence of Descemet's detachment and uveal inflammation, none of these complications were observed in our study. This apparent anomaly could be due to potential under-reporting in our dataset of minor, self-resolving complications, such as non-visual axis or planar Descemet's detachment, and uveal inflammation.

Table 5

Comparison of cataract surgery complications between 2 study groups
Complications	Present study (n = 44)	Nihalani et al (n = 84)
Subjects	Thai	Indian
Descemet’s detachment	0	5 (5.95%)
Corneal decompensation	1(2.22%)	0
Uveal inflammation (Cell, flare\(\:\ge\:\)3+)	0	10(12%)
Hyphema	1(2.22%)	0
Retained lens cortex	1(2.22%)	0
Ruptured PC	1(2.22%)	2(2.38%)
Transient corneal edema (at one week post operation)	14(31.81%)	12(14.3%)

This study highlights a significantly higher likelihood of complications in RAM patients compared to general cataract surgery patients, where complication rates are typically under 10% (31, 32). In the present study, RAM patients experienced transient corneal edema surpassing 30 %.

Furthermore, patients with RAM may face elevated risks, particularly when compounded by additional risk factors such as the involvement of less experienced surgeons, ACD ≤ 2.2 mm, and LAF ≥ 2.3. These findings are consistent with those of previous research, which has shown an association between surgical difficulty, increased endothelium damage resulting in post-operative corneal edema, challenges posed by limited working space, and a higher incidence of corneal guttata. (5, 6)

Study strengths and limitations

Current study had a strength of large dataset from a real-world practice. The optical biometer demonstrated a convenient tool to assess RAM. However, the study had some inherent limitations. Firstly, its retrospective nature may have introduced biases and could have resulted in incomplete data, potentially leading to under-reporting of surgical complications and impacting observed prevalence rates and associations. Inconsistencies in non-Goldmann applanation intraocular pressure data could also have further complicated matters. Additionally, as the study was conducted at a single center, the generalizability of our findings to broader populations may be restricted. The involvement of multiple surgeons using varied techniques also complicates the interpretation of surgical outcomes. Despite employing advanced technology like the IOL Master 700, variations in measurement techniques and device calibration may have affected the accuracy and reliability of our measurements. However, these limitations may simply mirror the complexities encountered in real-world scenarios.

This study investigated the prevalence of RAM and its correlation with glaucoma using real-world clinical data and advanced technology in the form of the optical biometer. While the prevalence of RAM was lower than previously thought, we found a higher incidence of glaucoma among RAM patients, especially in the closed-angle subtype. This underscores the importance of tailored management strategies for treatment of RAM patients with concurrent glaucoma in order to optimize outcomes and minimize complications. Additionally, early detection and preventive interventions, such as laser peripheral iridotomy, are crucial to mitigate the risk of acute angle-closure crises. These findings offer insights into the clinical importance of RAM, with the IOL Master serving as a valuable diagnostic tool, informing future interventions into these complex conditions.

Acknowledgements: We gratefully acknowledge the funding provided by Rajavithi Hospital in support of this research endeavor.

author contribution statement: KA was responsible for the overall direction and planning of the study and performed the analysis. WS contributed to interpreting the results and wrote the manuscript with support from KS. MC and NA processed the experimental data. KK provided statistical expertise. BW conceived the initial idea for the study and proofread the manuscript outline. All authors discussed the results and contributed to the final manuscript.

Conflicts of interest: None.

Funding: Rajavithi Hospital.

Data availability statement: The datasets generated and/or analyzed during the current study are not publicly available due to the exceptionally large data size but are available from the corresponding author on reasonable request.

Hoffman RS, Vasavada AR, Allen QB, Snyder ME, Devgan U, Braga-Mele R. Cataract surgery in the small eye. J Cataract Refract Surg. 2015 Nov;41(11):2565–75.
Bateman JB. Microphthalmos. Int Ophthalmol Clin. 1984 Spring;24(1):87-107.
Carricondo PC, Andrade T, Prasov L, Ayres BM, Moroi SE. Nanophthalmos: A Review of the Clinical Spectrum and Genetics. J Ophthalmol. 2018 May 9;2018:2735465.
Naumann GOH. Pathologie des Auges, 2nd ed. Berlin: Springer; 1997.p.1264–5.
Auffarth GU, Blum M, Tetz MR, Völcker HE. Relative anterior microphthalmos Morphometric analysis and its implications for cataract surgery. Ophthalmology. 2000;107(8):1555–60.
Nihalani BR, Jani UD, Vasavada AR, Auffarth GU. Cataract Surgery in Relative Anterior Microphthalmos. Ophthalmology. 2005;112(8):1360–7.
Wanichwecharungruang B, Amornpetchsathaporn A, Kongsomboon K, Wongwijitsook W, Annopawong K, Chantra S. Clinical evaluation of ocular biometry of dual Scheimpflug analyzer, GALILEI G6 and swept source optical coherence tomography, ANTERION. Sci Rep. 2022 Dec 1;12(1).
Wanichwecharungruang B, Amornpetchsathaporn A, Wongwijitsook W, Kongsomboon K, Chantra S. Evaluation of ocular biometry in primary angle-closure disease with two swept source optical coherence tomography devices. PLoS One. 2022 Mar 21;17(3):e0265844.
Hirzenberger CK, Hitzenberger CK. Optical Measurement of the Axial Eye Length by Laser Doppler Interferometry. Invest Ophthalmol Vis Sci. 1991;32(3):616-24.
Findl O, Drexler W, Menapace R, Hitzenberger CK, Fercher AF. High precision biometry of pseudophakic eyes using partial coherence interferometry. J Cataract Refract Surg. 1998 Aug;24(8):1087–93.
Rajan MS, Keilhorn I, Bell JA. Partial coherence laser interferometry vs conventional ultrasound biometry in intraocular lens power calculations. Eye. 2002 Sep 27;16(5):552–6.
Jung KI, Yang JW, Lee YC, Kim SY. Cataract Surgery in Eyes With Nanophthalmos and Relative Anterior Microphthalmos. Am J Ophthalmol. 2012 Jun;153(6):1161-1168.e1.
Foster PJ, Buhrmann R, Quigley HA, Johnson GJ. The definition and classification of glaucoma in prevalence surveys. Br J Ophthalmol. 2002 Feb;86(2):238-42.
Stein JD. Serious adverse events after cataract surgery. Curr Opin Ophthalmol. 2012 May;23(3):219-25.
Lin IH, Lee CY, Chen JT, Chen YH, Chung CH, Sun CA, Chien WC, Chen HC, Chen CL. Predisposing Factors for Severe Complications after Cataract Surgery: A Nationwide Population-Based Study. J Clin Med. 2021 Jul 28;10(15):3336.
Markowitz SN, Donald Morin J. The Ratio of Lens Thickness to Axial Length for Biometric Standardization in Angle-Closure Glaucoma. Am J Ophthalmol. 1985 Apr;99(4):400–2.
Ang RET, Reyes EKF, Ayuyao FAJ, Umali MIN, Cruz EM. Comparison of white-to-white measurements using four devices and their determination of ICL sizing. Eye Vis. 2022 Oct 2;9(1):36.
Baumeister M, Terzi E, Ekici Y, Kohnen T. Comparison of manual and automated methods to determine horizontal corneal diameter. J Cataract Refract Surg. 2004 Feb;30(2):374–80.
Dong J, Zhang Y, Zhang H, Jia Z, Zhang S, Wang X. Comparison of axial length, anterior chamber depth and intraocular lens power between IOL Master and ultrasound in normal, long and short eyes. PLoS One. 2018 Mar 15;13(3): e0194273
Bai QH, Wang JL, Wang Q, Yan QC, Zhang JS. The measurement of anterior chamber depth andaxial length with the IOL Master compared with contact ultrasonic axial scan. Int J Ophthalmol. 2007 Aug 1;1:151–4.
Gaballa SH, Allam RS , Abouhussein NB, Raafat KA. IOL Master and A-scan biometry in axial length and intraocular lens power measurements. Delta J. Ophthalmol. 2017;18(1):13-9.
Rathod S, Raj DN, Narasimhamurthy B, Vidyadevi M, Sadananda RC, Anupriya A. A Study on Comparison of Axial Length and IOL Power in A-Scan Biometry versus IOL Master. J. Evid. Based Med. Healthc. 2020 Mar 23;7(12):587–90.
Gopi R, Sathyan S. Comparison of ocular biometry parameters between IOL Master and applanation A-scan in eyes with short, medium, long, and very long axial lengths. Kerala J Ophthalmol. 2017;29(1):35-40.
Rose LT, Moshegov CN. Comparison of the Zeiss IOL Master and applanation A‐scan ultrasound: biometry for intraocular lens calculation. Clin Exp Ophthalmol. 2003 Apr 28;31(2):121–4.
Blake CR, Lai WW, Edward DP. Racial and Ethnic Differences in Ocular Anatomy. Int Ophthalmol Clin. 2003;43(4):9–25.
Fahnehjelm C, Dafgård Kopp E, Wincent J, Güven E, Nilsson M, Olsson M, Teär Fahnehjelm K. Anophthalmia and microphthalmia in children: associated ocular, somatic and genetic morbidities and quality of life. Ophthalmic Genet. 2022 Apr;43(2):172-183.
Tham YC, Li X, Wong TY, Quigley HA, Aung T, Cheng CY. Global Prevalence of Glaucoma and Projections of Glaucoma Burden through 2040. Ophthalmology. 2014 Nov;121(11):2081–90.
Allison K, Patel D, Alabi O. Epidemiology of Glaucoma: The Past, Present, and Predictions for the Future. Cureus. 2020 Nov 24; 12(11):e11686
Park SJ, Park KH, Kim TW, Park BJ. Nationwide Incidence of Acute Angle Closure Glaucoma in Korea from 2011 to 2015. J Korean Med Sci. 2019;34(48):e306.
Seah SK, Foster PJ, Chew PT, Jap A, Oen F, Fam HB, Lim AS. Incidence of Acute Primary Angle-closure Glaucoma in Singapore. Arch. Ophthalmol. 1997 Nov 1;115(11):1436-40.
Tufail A, Foss AJ, Hamilton AM. Is the first day postoperative review necessary after cataract extraction? Br J Ophthalmol. 1995 Jul;79(7):646-8.
Tan JH, Newman DK, Klunker C, Watts SE, Burton RL. Phacoemulsification cataract surgery: is routine review necessary on the first post-operative day? Eye. 2000 Jan;14(1):53–5.

No competing interests reported.

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Prevalence and Clinical Associations of Relative Anterior Microphthalmos assessed with an Optical Biometer

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Abstract

Background/Objective:

Subject/Methods:

Results

Conclusion

Introduction

Materials/Subjects and Methods

Definition of RAM

Definition of glaucoma

Statistical analysis

Results

Cataract surgery and its complications in RAM

• IOP reduction and number of IOP-lowering medications

• Surgical complications

Discussion

Glaucoma association

Cataract surgery-related complication

Study strengths and limitations

Conclusion

Declarations

References

Additional Declarations

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Version 1