Scleral Lenses Research Articles

Medmont Meridia™: Much More Than a Corneal Topographer.

In recent years, advanced diagnostic instruments have become widely available in optometric practices, offering various functions that optimize clinical information gathering. This article focuses on the Medmont Meridia™, a state-of-the-art multipurpose diagnostic device with corneal topography and cutting-edge features. Corneal topography is pivotal in the early diagnosis of corneal disorders, determining baseline ocular surface assessment, helping in contact lens fitting, and monitoring ocular health over time. The Medmont Meridia boasts Placido-disc-based imaging with extensive corneal coverage. Furthermore, the Meridia accurately measures the horizontal visible iris diameter, pupil diameter, and palpebral fissure width, which assists in making contact lens parameter decisions. Additionally, it offers sagittal height data for scleral lens design and first lens selection, streamlining the fitting process. Beyond its topography capabilities, the Meridia excels as a comprehensive dry eye assessment tool. With features like tear meniscus height, tear film surface quality, and meibography capabilities, it aids in diagnosing dry eye and monitoring its progression. The device also provides customizable dry eye reports with integrated grading scales and questionnaires, making dry eye management, patient education, and compliance more accessible. In conclusion, the Medmont Meridia consolidates a multitude of examination tools in a single instrument, enhancing practice efficiency and elevating patient care and communication. Its versatility and accuracy make it an invaluable asset in optometric practices worldwide.

Quality of life and vision assessment with scleral lenses in keratoconus.

The purpose of the study is to evaluate the visual outcomes and improvement in quality of life (QOL) of patients with keratoconus with scleral lenses. In this prospective study, 14 patients (28 eyes) with bilateral keratoconus were fitted with scleral lenses (McAsfeer 16.00 mm) in Pune city, Maharashtra, India. Uncorrected visual acuity (VA), best spectacle-corrected VA, and VA with scleral lenses were evaluated. The patients were given the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) for judging the QOL, before and after using scleral lenses for 3 months. The mean uncorrected VA of the 14 patients with a mean age of 28.64 ± 6.57 years was 1.18 ± 0.19 logMAR. Best spectacle-corrected high-contrast VA improved from 0.47 ± 0.25 logMAR to 0.03 ± 0.07 logMAR with scleral lenses (P < 0.001). Best spectacle-corrected low-contrast VA improved from 0.68 ± 0.22 logMAR to 00.47 ± 0.10 logMAR with scleral lenses (P < 0.001). Along with the increase in overall median scores on the NEI VFQ-25 from 1735 to 2930 points (P < 0.001), the distance and near activities (P < 0.001), vision-specific mental health (P < 0.002), social functioning (P < 0.004), and driving (P < 0.005) improved after using scleral lenses for 3 months. Scleral lenses can be an effective and safe management option for patients with keratoconus leading to an improved vision and QOL.

Prospective assessment of corneal biomechanical properties and intraocular pressure after scleral lens wear: A 12-month follow-up study

PurposeTo investigate the long-term influence of scleral lens (SL) wear on corneal biomechanical properties and intraocular pressure (IOP) in irregular and regular corneas. Secondary goal comprised evaluate the fluid reservoir (FR) thickness overtime and correlate it with the changes in corneal biomechanical parameters and IOP. MethodsSeventy (70) eyes with irregular corneas (IC Group) and 21 eyes with regular corneas (RC Group) were fitted with 16.4 mm SL and wore the lenses for 12 months. Corrected IOP (IOPcc), Goldmann equivalent IOP (IOPg) and corneal biomechanical parameters (Corneal Hysteresis (CH) and Corneal Resistance Factor (CRF)) were measured with Ocular Response Analyzer. Slit lamp images were analyzed with ImageJ software to assess FR thickness overtime. Measurements were taken at lens dispensing visit prior lens wear (LDV1) and after 60 min of lens wear (LDV2) and at 1, 6 and 12-month follow-up visits. Measurements were done immediately after lens removal. ResultsThere were no statistically significant differences on IOPcc, IOPg, CRF and CH over the follow-up visits in both groups. Mean IOPcc and IOPg fluctuations overtime were clinically insignificant and below 1 mmHg in both groups. IOPg, CH and CRF were significantly lower on IC Group (p < 0.001), although no statistically significant differences were found between groups for IOPcc. Regarding FR thickness, statistically significant differences were found over the follow-up on both groups, with a mean decrease of 186.29 µm on IC Group and 175.32 µm on RC Group (p < 0.001). Statistically significant moderate to high negative correlations between FR and IOPg, CRF and CH were found only in the RC Group. ConclusionsLong-term SL wear was not associated to changes in corneal biomechanical parameters neither on IOP as measured after lens removal. Besides IOP measurement without SL removal, more studies are needed to investigate the potential relationship with SL fitting characteristics (namely FR thickness).

Characterization of the external limbus on corneoscleral topography with ultrawide-field optical coherence tomography

PurposeTo present a new method for 3-dimensional external limbal demarcation on corneoscleral topography derived from optical coherence tomography (OCT). Limbal shape is investigated and compared to other landmarks. MethodsImages from the anterior segment were obtained with a ultrawide-field (20 mm) OCT. An automated algorithm was developed to demarcate the topographic limbus based on the transition from corneal to scleral curvature. The internal limbus was manually identified as the scleral spur on the OCT images. The external topographic limbus was fit with a circle on a plane. Ellipticity and ovality were defined by the lateral limbal deviation from the best-fit circle. Toricity was defined by the axial deviation from the best-fit plane. Repeatability was assessed by the within-subject standard deviation from two repeated measurements. For comparison, the white-to-white (WTW) diameter was obtained from Pentacam HR. Results18 eyes from 11 subjects were analyzed. The topographic limbal diameter was 12.16 ± 0.68 mm (mean ± standard deviation) horizontally and 11.18 ± 0.65 mm vertically. The repeatability for the topographic limbal diameter was 0.054 mm. The internal and WTW horizontal limbal diameters were significantly smaller (linear mixed-effects model (GLMM), p <.017). The vertical internal limbal diameter was significantly larger (GLMM p <.05). The topographic limbus had significant ellipticity (0.25 ± 0.13 mm, wider horizontally, repeatability of 0.07 mm) and toricity (0.15 ± 0.08 mm, flatter horizontally, repeatability of 0.10 mm). Low coefficients of determination were found for the topographical limbus with the internal limbus (R2=0.021 and R2=0.039, for horizontal and vertical diameters respectively) and with the WTW (R2=0.146 for the horizontal diameter). ConclusionThe proposed method to demarcate the 3D external topographical limbus is repeatable. The topographic limbal shape and size cannot be accurately derived from WTW nor internal limbus measures. This new technology may improve the process of scleral lens fitting.

Comparative analysis of the correction of irregular postkeratoplastic astigmatism with scleral lenses and intrastromal ring implantation

Background. Many patients after penetrating keratoplasty (PK) experience induced postkeratoplastic astigmatism, which is often irregular and causes an increase in corneal aberrations that reduce visual acuity and quality. The aim of the study. To conduct a comparative analysis of the effect of rigid gas permeable scleral lenses and the MyoRing implantation method on clinical and functional parameters in patients with IPA. Material and methods. The clinical study included 60 patients (60 eyes). The age of patients with IPA was from 25 to 42 years. All patients underwent penetrating keratoplasty. All patients were divided into two groups depending on the method for irregular postkeratoplastic astigmatism correction. Group I included 30 patients (30 eyes) who were fitted with rigid gas permeable scleral lenses. Group II consisted of 30 patients (30 eyes) who underwent implantation of the MyoRing into a penetrating corneal graft. The observation period was 1 year. Results. After 12 months of observation, there was a greater increase in uncorrected visual acuity by an average of 3 lines, in corrected visual acuity – by 2 lines; a greater decrease in corneal aberrations in photo- (root mean square (RMS) of total aberrations (RMS total) by 0.30 ± 0.08 µm, RMS of higher order aberrations (RMS HOA) – by 1.01 ± 0.24 μm) and mesopic conditions (RMS total – by 0.33 ± 0.09 μm, RMS HOA – by 0.08 ± 0.03 μm) in patients wearing rigid gas permeable scleral lenses compared with patients after MyoRing implantation into a penetrating corneal graft. Conclusion. Patients of group I, wearing rigid gas permeable scleral lenses, showed a greater improvement in visual acuity and a decrease in corneal aberrations in photo- and mesopic conditions compared to the patients of group II (after MyoRing implantation) at a follow-up period of 12 months.

The results of a laboratory and clinical study evaluating the disinfecting properties multifunctional solution “OKVision GOLD” in relation to gas-permeable lenses

Introduction. The modern realities of the Russian market of contact lens care products dictate the search for a universal solution for one-stage cleaning, which has high disinfecting and cleansing properties for all types of contact lens materials.Purpose: investigation of the disinfecting properties of the multifunctional solution “OKVision GOLD” in relation to scleral gas-permeable lenses.Materials and methods. 20 patients (40 eyes) with keratoconus of various stages (average age 32.6 ± 2.3 years) were examined before and after wearing scleral lenses in the daytime. A clinical ophthalmological study was conducted, including a biomicroscopic assessment of the lens surfaces, as well as the anterior segment of the eye with the use of vital dyes before and after lens cleaning. In addition, smears were collected for further bacteriological examination. Evaluated: a) initial smear from the conjunctiva of the patient before putting on the contact lens; b) a smear from two surfaces of the lens after wearing it for 12 hours; c) a smear from two surfaces of the lens after 6 hours of treatment in solution. The place of analysis: G.N. Gabrichevsky research institute for epidemiology and microbiology.Results. Sowing smears from the conjunctiva before using contact correction revealed the presence of opportunistic flora. Sowing after 12 hours of wearing lenses determined the attachment of pathogenic flora. Examination of smears from lens surfaces after their 6-hour exposure in solution revealed complete inactivation of previously detected pathogenic and insignificant presence of conditionally pathogenic flora. During biomicroscopy, the condition of the eye surface remained unchanged, no deposits on the lenses were recorded. The survey of patients also revealed no negative reactions.Conclusion. The results of clinical and bacteriological studies indicate high disinfecting activity against conditionally pathogenic and conditionally pathogenic flora in the treatment of scleral lenses. This solution can be recommended for the care of all types of contact lenses, including gas-permeable ones.

Problemlösung bei komplizierten kornealen Verhältnissen: Sklerallinsen und deren Anpassung mit neuen modernen Messmethoden

Purpose. The case report describes the follow up fitting with scleral contact lenses for visual rehabilitation in advanced keratoconus and the influence of the scleral fitting characteristics on the daily wearing time as well as the wearing comfort of the contact lenses. Material and Methods. Scleral contact lenses were fitted using Scheimpflug images and analysis of optical coherence tomography cross-sectional images. Based on this data an optimization of the contact lens design could be performed. Results. In the present case, a significant improvement in visual acuity, daily wearing time and wearing comfort was achieved due to scleral lens re-fitting with individual scleral lens sagittal height calculation and custom fitting according to corneo-scleral profile measurement data. Conclusion. Scleral lenses can be a good alternative to other contact lens treatments to achieve visual rehabilitation in complex corneal situations. Analysis of the corneo-scleral profile by Scheimpflug technique and accurate evaluation of the sagittal height are of great benefit, in addition to the assessment of the fitting and landing zone of scleral lenses by anterior segment OCT. This results in significant time savings for the fitting and leads to a more physiologically compatible contact lens treatment result. Keywords keratoconus, scleral lenses, optical coherence tomography (OCT), corneo-scleral profile (CSP)

Keratokonus, Sklerallinsen und Glaukom-Drainage-Implantat

Purpose. This case report describes scleral lens fitting for advanced keratoconus in combination with additional glaucoma surgery. Material and Methods. The implantation of a drainage implant was followed by the bilateral fitting of scleral lenses. For contact lens fitting, it was essential to work with a scleral lens system that allows individual zone size and edge clearance in the scleral alignment zone to prevent provocation of the postoperative area. Results. Due to the individualized design of the scleral lenses, the patient was able to wear scleral lenses again postopera- tively with successful implantation of a drainage implant. A prerequisite for this was also that the surgeon considered the necessity of a later postoperative fitting with scleral lenses when choosing the surgical method. Conclusion. Scleral lenses can also be successfully fitted in cases of complex corneal shapes and surgical procedures on the eye. This requires not only a great clinical experience in fit- ting such contact lenses, but also an individual manufacturing of the contact lenses based on the contact lens parameters specified by the contact lens specialist. Keywords drainage implant, scleral lens with peripheral torus, zone size, x-value

Analysis of Corneo-scleral Measurements and Ocular Biometry as Predictors of Scleral Lens Parameters: A Review

Purpose. In the latest years, the interest in scleral lenses is progressively increasing among practitioners and patients from all around the world. An optimal lens fit is necessary to ensure patient comfort and visual quality. However, it is not straightforward to estimate the appropriate scleral lens parameters for a particular patient. This review paper aims to summarize the current state of knowledge in predictors of scleral lens parameters based on corneo-scleral shape. Material and Methods. Literature was reviewed from PubMed. A total of 33 articles were specifically selected for the current study. Results. Even though not all available corneo-scleral meas- urements may be helpful in the fitting experience, the re- fractive state of the cornea, corneal flattest and steepest keratometry, scleral toricity, and axial length have proven to influence the scleral lens parameters and, consequently, the quality of scleral lens fit. Conclusion. The usefulness of corneal, scleral, and corneo- scleral measures is reviewed and critically evaluated. A special effort was made to highlight the clinical implications of the findings. Keywords Corneal topography, scleral profile, profilometry, myopia progression, axial length, contact lens fitting

Guide for Successful Scleral Lens Fitting

To date, scleral contact lenses have been known only as large-sized contact lenses with an uncomfortable fit, intended exclusively for patients with severe ocular surface diseases. However, with the recent introduction of scleral contact lenses ranging from 14 to 16 mm, designed considering the corneal and eyelid shapes of Asians, it has become possible to prescribe scleral contact lenses for a broader range of corneal disease patients. Patients with severe ocular surface diseases, keratoconus, and irregular astigmatism post-corneal transplantation have shown visual improvement after wearing scleral contact lenses. In this review article, we aim to discuss scleral contact lenses, including their indications and fitting methods.

Results of intrastromal corneal ring implantation in advanced keratoconus With the aim of postpoing or avoiding corneal transplantation.

To evaluate the safety and efficacy of the surgery of intracorneal ring segment implantation with 320° of arc (320-ICRS) in patients with advanced keratoconus stage IV and maximum keratometry (Kmax) above 60 D. A prospective, interventional case series study evaluating 25 eyes of 19 patients with keratoconus stage IV and Kmax > 60D in which 320-ICRS were implanted using VisuMax® femtosecond. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometric values (mean - mean-K, flat - K1, and steep - K2), maximum keratometry (Kmax), tomographic astigmatism, refractive astigmatism and asphericity (Q) were assessed preoperatively and at 3, 6 and 12 months after the procedure. The UDVA improved from 1.03 ± 0.28 LogMAR (20/200) to 0.54 ± 0.21 LogMAR (20/60), (p < 0.001), the CDVA (with glasses) improved from 0.63 ± 0.29 LogMAR (20/80) to 0.31 ± 0.16 LogMAR (20/40),(p = 0.004), K1 reduced from 54.41 ± 4.46 D to 49.36 ± 4.11 D (p < 0.001), K2 reduced from 61.15 ± 4.37 D to 53.715 ± 4.05 D, (p < 0.001), mean-K reduced from 57.55 ± 4,17 D to 51.44 ± 3,94 D (p < 0.001), Kmax reduced from 69.80 ± 8.20 D to 63.43 ± 6.31 D (p < 0.001) and asphericity (Q) changed from -1.57 ± 0.35 to -0.77 ± 0.56 (p < 0.001). A total of 89.9% patients reached BCVA wearing scleral contact lens 0.2 LogMAR(20/25). 320-ICRS to treat advanced keratoconus appears to be an efficacious and safe procedure, being a surgical alternative to delay or even prevent corneal transplantation.

Keratoconus Diagnosis and Treatment: Recent Advances and Future Directions.

Keratoconus is a disorder characterized by progressive corneal thinning and steepening that may result in significant visual impairment secondary to high astigmatism, corneal scarring, or even corneal perforation. Early detection and screening of keratoconus are essential for effective management and treatment. Several screening methods, such as corneal topography and tomography, corneal biomechanics, and genetic testing, are being developed to detect keratoconus at an early stage. Once detected, prevention of progression is the mainstay of keratoconus management. Corneal collagen cross-linking is a minimally invasive treatment option that can slow or halt the progression of keratoconus. Additionally, recent studies have investigated the potential use of copper sulfate eye drops (IVMED-80) and extracellular vesicles to prevent the progression of keratoconus as non-invasive treatment options. For visual rehabilitation, currently available treatments include scleral lenses, intracorneal ring segments, corneal allogenic intrastromal ring segments, and deep anterior lamellar keratoplasty. The safety and efficacy of these emerging treatment options for keratoconus are currently being investigated.

Ocular Surface Homeostasis After Scleral Lens Usage.

The aim of this prospective study is to examine the effects of 5 hours of well-fitted, mini-scleral contact lens (mini-SL) wear on the tear film cytokine expression in healthy eyes. Twenty-three healthy participants were included in the study. One eye of each participant was selected at random, and a mini-SL measuring 16.5 mm in diameter was fitted by an experienced contact lens specialist. The contact lens remained in place for 5 hours. Precorneal tear fluid was collected using capillary tubes at three different time points: baseline before SL insertion (T0), after 5 hours of SL wear (T1), and 3 hours after SL removal (T2). The concentration of 40 inflammatory cytokines at the three different time points was determined using multiplex bead assay. Mini-scleral lens wear did not result in significant changes in the cytokine-to-protein ratio after 5 hours of wear on a healthy eye. Although a well-fitted mini-SL reduces the rate at which the precorneal tear film is refreshed, 5 hours of lens wear did not appear to significantly affect the tears cytokine-to-protein ratio, suggesting that scleral lenses have minimal impact on corneal cytokine expression.

Scleral sutured toric intraocular lens with pars plana vitrectomy for the correction of corneal astigmatism without capsular support.

To describe the repair of a patient with bilateral subluxed cataract and corneal astigmatism in the setting of a coloboma of the iris, zonules, lens, and retina. Pre-operatively his best corrected acuity was 20/500 OD and 20/200 OS. His pre-operative refraction was -7.25 +1.00 at 080 OD and -7.75 +3.00 at 040 OS. On corneal topography, he had 1.95D and 1.45D of regular astigmatism in the right and left eye respectively. This technique involves pars plana vitrectomy in combination with the placement of a MX60 toric intraocular lens fixated to the sclera using 8-0 Gore-Tex in line with the axis of steep corneal astigmatism. The lens is affixed through two pair of nasal and temporal sclerotomies, with each pair located 3 mm posterior to the limbus and 5 mm apart, centered along the axis of steep astigmatism. Post-operatively the patient was 20/25 uncorrected OD and 20/20 uncorrected OS with a refraction of -0.75 +0.50 at 180 in the OD and -0.75 +1.00 at 180 in the OS. Scleral sutured toric intraocular lens placement and pars plana vitrectomy is a viable solution for patients with regular corneal astigmatism and cataract repair in the absence of zonular support.

Central and peripheral scleral lens-induced corneal oedema.

To quantify the magnitude of central and peripheral scleral lens-induced corneal oedema for a range of fluid reservoir thicknesses, and to compare these experimental results with theoretical models of corneal oedema both with and without limbal metabolic support (i.e., the lateral transport of metabolites and the influence of the limbal vasculature). Ten young healthy participants wore scleral lenses (KATT™, Capricornia Contact Lenses) fitted with low (mean 141 μm), medium (482 μm) and high (718 μm) central fluid reservoir thickness values across three separate study visits. The scleral lens thickness, fluid reservoir thickness and stromal corneal oedema were measured using optical coherence tomography. Oedema was quantified across the central (0-2.5 mm from the corneal apex) and peripheral (1.25-3 mm from the scleral spur) cornea. Experimental data were compared with published theoretical models of central to peripheral corneal oedema. Stromal oedema varied with fluid reservoir thickness (p < 0.001) for both central and peripheral regions. The mean (standard deviation) stromal oedema was greater for the medium (2.08 (1.21)%) and high (2.22 (1.31)%) fluid reservoir thickness conditions compared to the low condition (1.00 (1.01)%) (p ≤ 0.01). Stromal oedema gradually increased from the corneal centre to the periphery by ~0.3% on average (relative increase of 18%), but the change did not reach statistical significance. This trend of increasing, rather than decreasing, oedema towards the limbus is consistent with theoretical modelling of peripheral oedema without metabolic support from the limbus. The central and peripheral cornea displayed a similar magnitude of oedema, with increasing levels observed for medium and high fluid reservoir thicknesses. The gradual increase in oedema towards the limbus is consistent with a 'without limbal metabolic support' theoretical model.

Quintuple Procedure for Ocular Surface Reconstruction and Visual Rehabilitation.

The aim of this study was to describe a combined surgical approach for ocular surface and visual rehabilitation in patients with limbal stem cell deficiency, corneal scarring, and cataract. We aimed to introduce this combined approach as an alternative to a staged approach and to describe the intraoperative use of a diamond ophthalmic burr (DOB) and optical coherence tomography (OCT) to achieve and confirm a smooth graft-host interface during the anterior lamellar keratoplasty (ALK) portion of the procedure. The quintuple procedure described herein consists of a modified ALK, cataract extraction, intraocular lens implantation, simple limbal epithelial transplantation, and temporal tarsorrhaphy. Intraoperative OCT and DOB were used to guide the creation of the stromal bed during the ALK. The procedure was performed in a patient with limbal stem cell deficiency and corneal scarring after a chemical ocular burn. The tarsorrhaphy was removed at 3 months postoperatively once complete corneal epithelialization was observed. The best-corrected visual acuity improved from light perception preoperatively to 20/30 at 16 months postoperatively with the use of scleral contact lenses. At this postoperative time point, the cornea was clear and compact, and the ocular surface was stable. The quintuple procedure allowed for visual and ocular surface rehabilitation in cases in which follow-up for a staged approach was not possible. Intraoperative OCT allowed for real-time visualization and dissection of the stromal bed, whereas the use of the DOB helped achieve a smooth stromal surface for an optimal graft-host interface.

High Astigmatism Secondary to Peripheral Ectasia Recurrence in Postpenetrating Keratoplasty Eyes Managed With Miniscleral Contact Lenses.

After penetrating keratoplasty (PK) for keratoconus, vision can be impaired by high-degree astigmatism, particularly in those patients with recurrent peripheral ectasia. Scleral contact lenses (CLs) have long been used in the management of keratoconus both in treatment-naive corneas and those postcorneal transplants. We report the use of miniscleral CLs and their related visual and clinical outcomes in a series of patients with post-PK peripheral rim ectasia. In this retrospective case series, 5 patients (7 eyes) presented because of reduced visual acuity with their spectacles/CLs and/or reduced comfort with their existing rigid gas-permeable lenses. All patients in this series underwent PK more than two decades ago for keratoconus (mean 28.7 years±7.2). All patients demonstrated characteristic thinning at the graft-host junction, with anterior chamber deepening. Central corneas had remained clear in all patients inferring high visual potential. Contact lenses used were No 7 Comfort 15 miniscleral and the Onefit MED scleral with 14.5 mm and 15.6 mm diameters, respectively. All eyes achieved a best-corrected visual acuity of 6/9 or greater. One case had difficulty with insertion and removal and has since discontinued wearing lens at this time. All others are successfully wearing the lenses regularly. Despite advances in CL design, surgical management is still required in some patients. Miniscleral CLs are effective in the refractive management of peripheral ectasia in keratoconic post-PK eyes and should be considered in such eyes before proceeding with repeat surgical intervention.

Average Scleral Lens Replacement Period at a Tertiary Care Hospital.

To evaluate the average scleral lens replacement period at a tertiary care hospital. Patients were identified retrospectively through electronic medical records. Inclusion criteria included scleral lens patients treated at the USC Department of Ophthalmology who had reordered a scleral lens at least once in one eye. Lens order histories were evaluated, and statistical analysis included a multivariable, mixed-methods, linear, regression model. Two hundred fifty-one patients (120 men and 131 women; average age 57.1±17.4 years, range 9-93 years) and a total of 445 eyes (227 OD, 218 OS; 199 irregular corneas, 246 ocular surface disease) were included. The average replacement period for a scleral lens was 23.9±14.3 months (range 5-2,617 days). Patients with greater scleral lens experience had a statistically significant increase in their average scleral lens replacement period; for every one year of additional experience wearing scleral lenses, average replacement period increased by 30.7 days ( P =0.001). There was no statistically significant correlation between average scleral lens replacement period and sex, diagnosis, prior outside scleral lens treatment, lens brand, or lens diameter. The average scleral lens replacement period in this patient cohort at a tertiary care hospital was 23.9±14.3 months (1.99±1.19 years). Further studies are needed to better understand the impact of scleral lens age on ocular health and vision. Certainly, proper scleral lens training and education are essential to ensure optimal lens condition and treatment outcomes.

Assessment by Optical Coherence Tomography of Short-Term Changes in IOP-Related Structures Caused by Wearing Scleral Lenses.

The mechanism that could increase intraocular pressure (IOP) during scleral lens (SL) wear is not fully understood, although it may be related to compression of the landing zone on structures involved in aqueous humor drainage. Thirty healthy subjects were fitted with two SLs of different sizes (L1 = 15.8 mm, L2 = 16.8 mm) for 2 h in the right eye and left eye as a control. Central corneal thickness (CCT), parameters of iridocorneal angle (ICA), Schlemm's canal (SC), and optic nerve head were measured before and after wearing both SLs. IOP was measured with a Perkins applanation tonometer before and after lens removal and with a transpalpebral tonometer before, during (0 h, 1 h, and 2 h), and after lens wear. CCT increased after wearing L1 (8.10 ± 4.21 µm; p < 0.01) and L2 (9.17 ± 4.41 µm; p < 0.01). After L1 removal, the ICA parameters decreased significantly (p < 0.05). With L2 removal, nasal and temporal SC area and length were reduced (p < 0.05). An increased IOP with transpalpebral tonometry was observed at 2 h of wearing L1 (2.55 ± 2.04 mmHg; p < 0.01) and L2 (2.53 ± 2.22 mmHg; p < 0.01), as well as an increased IOP with Perkins applanation tonometry after wearing L1 (0.43 ± 1.07 mmHg; p = 0.02). In the short term, SL resulted in a slight increase in IOP in addition to small changes in ICA and SC parameters, although it did not seem to be clinically relevant in healthy subjects.

A clinical case of fitting scleral contact lenses for congenital bilateral eyelid coloboma complicated by exposure keratopathy

A clinical case of fitting scleral contact lenses for congenital bilateral eyelid coloboma complicated by exposure keratopathy