Case Report 8 – Mini-Scleral & Scleral RGPs

2 MAIN AREAS

Extreme ectasia / Corneal RGP intolerance / End Stage
Corneal Neuropathic Pain
1. Corneal Hyperalgesia (plus or minus lacosamide depot Tx)
2. Ocular Surface Disease
3. Chronic Dry Eye

The argument for large diameter RGP contact lenses – Scleral and Mini-Scleral RGPs

No corneal touch / insult
Vault very proud /messy ectasias / PK – tilted grafts, graft host junction disease and ectasia
Large footprint on sclera
Stable with good centration
Can not fall out (swimming / bungee jumping/surfing)
No dust under lenses
Big tear reservoir
White eyes – in the absence of atopic and inflammatory eye disease
No glare – well it is minimised depending on ectasia location relative to optic zone
No ptosis – better for patients post graft with surgery induced lid damage
Large corneal clearance = longer lens life = more wiggle room for keratoconus and ectasia progression in the absence of corneal cross linking.

Need to think and calculate in terms of Sag over a chord….. Use topography just to paint a picture and help determine severity.

Touch

Ideal

Too much

Landing Zone is a Tangent with alignment fit

Case – Bilateral extreme (early onset) keratoconus

18 yo male advanced keratoconus OS>OD
BILATERAL Hydrops + neo + scarring
OD: UAVA 6/CF+ & OS: VA 6/CF-
CCT OD: 290um / OS: 280um
Patanol bd OU.

Contact Lens Parameters

Gelflex mini-scleral RGP in Harmony Plus material
OD: 7.00/12.50/15.25/18.50/-7.25 CT 220um Sag 5857um (6/12=)
OS: 7.35/12.50/15.25/18.50/-5.25 CT 220um Sag 6178um (6/15=)

Acute Hydrops in advanced keratoconus:

Case Report 8 – Scleral Lenses in Extreme Keratoconus: Sagittal Depth, Landing Zones and Advanced Fitting

Why Do We Fit Scleral Lenses?

The original version of this case described two broad groups in which large-diameter rigid lenses can be particularly valuable:

1. Irregular Corneas

Including:

advanced keratoconus;
pellucid marginal degeneration;
post-corneal graft irregularity;
graft-host junction ectasia;
post-refractive surgery ectasia;
corneal scarring; and
patients intolerant of corneal GP lenses.

2. Ocular Surface Protection

Including selected patients with:

severe dry eye disease;
exposure keratopathy;
neurotrophic keratopathy;
ocular graft-versus-host disease;
severe ocular surface disease; and
selected cases of corneal neuropathic pain.

A scleral lens can simultaneously provide:

a regular rigid anterior optical surface

and

a fluid reservoir separating the lens from the cornea.

That combination is what makes the modality so powerful.

First 2026 Update – What Do We Call These Lenses?

The historical page refers repeatedly to:

“Mini-scleral RGPs”

Modern terminology is more precise.

The Scleral Lens Education Society recommends defining rigid lenses primarily according to where the lens bears, rather than assigning the name solely from overall diameter.

Corneal GP

Bears predominantly on the cornea.

Corneo-scleral GP

Shares support between cornea and conjunctiva/sclera.

Scleral Lens

Vaults the cornea and limbus and bears predominantly on the conjunctiva overlying the sclera.

Historically, terms such as mini-scleral and large scleral were based upon diameter relative to the visible iris diameter.

For teaching purposes in 2026, the more important question is therefore:

Where does the lens land?

An 18.50 mm lens is not automatically “mini-scleral” simply because that was the historical product description.

The fitting relationship matters more than the label. [1]

Why Use a Scleral Lens?

The original page listed a number of advantages. The underlying concepts remain sound, but some require qualification.

Potential advantages include:

complete or near-complete corneal vault;
avoidance of significant mechanical interaction with an ectatic cone;
excellent lens stability;
good centration;
a large optical zone;
protection from environmental exposure;
reduced risk of corneal GP dislodgement;
a fluid reservoir over the ocular surface;
ability to vault highly irregular grafts or ectatic corneas;
excellent correction of anterior corneal irregular astigmatism; and
potentially excellent comfort.

However:

A scleral lens is not physiologically invisible.

Potential problems include:

corneal oedema;
excessive fluid reservoir thickness;
conjunctival compression;
limbal bearing;
lens suction;
midday fogging;
air bubbles;
lens flexure;
decentration;
surface deposits;
handling difficulties; and
microbial keratitis in susceptible eyes.

Modern scleral fitting is therefore not:

“Make the lens big and clear everything.”

It is:

Create the minimum physiologically appropriate vault, optimise the landing zone, stabilise the optics and maintain ocular health.

Think in Sagittal Depth – Not Just Base Curve

This remains one of the most important concepts on the original page.

Think SAG over a CHORD.

Figure 1. Original OCT image demonstrating sagittal depth measured from a defined chord. Scleral lens fitting is fundamentally a sagittal-depth problem rather than simply a central base-curve problem.

A corneal GP lens is traditionally discussed heavily in terms of:

base curve radius.

A scleral lens requires a different way of thinking.

The clinician needs to consider the sagittal height of the ocular surface over a specified chord diameter.

Why?

Two corneas can have very similar central keratometry yet have completely different sagittal heights because of differences in:

eccentricity;
peripheral corneal shape;
cone position;
limbal geometry;
scleral shape; and
overall ocular surface contour.

Likewise, changing the total diameter of a scleral lens changes the chord over which its sagittal depth is expressed.

Therefore:

A sagittal depth value is meaningless unless you also know the chord diameter at which it was measured.

This is one of the most important principles for students moving from corneal GP fitting into scleral lens design.

Base Curve Is Only One Component

Figure 2. Cross-sectional appearance illustrating the sagittal relationship between the posterior lens surface and cornea.

A scleral lens is better conceptualised as a series of geometric zones:

Optical / Corneal Zone

Controls much of the relationship over the central cornea.

Limbal / Transition Zone

Provides clearance across the peripheral cornea and limbus.

Landing Zone

Transfers lens support onto the conjunctiva overlying the sclera.

Changing any one of these can alter the behaviour of the entire lens.

This is why two lenses with the same nominal base curve may fit completely differently.

Three Central Fitting Relationships

The original case illustrates three useful extremes.

1. Corneal Touch – Too Little Sag

Figure 3. Historical image demonstrating inadequate sagittal depth with central corneal touch.

In an advanced ectatic cornea, significant central or apical bearing defeats one of the principal reasons for choosing a scleral design.

Potential consequences include:

epithelial disruption;
staining;
discomfort;
mechanical trauma;
disruption over a fragile cone;
scarring; and
unstable optics.

Management

Increase the appropriate sagittal component rather than simply assuming that:

“The base curve needs to be steeper.”

The required change may involve:

central vault;
limbal geometry;
overall sagittal depth;
diameter; or
combinations of these.

2. Appropriate Corneal Clearance

Figure 4. Historical image demonstrating an appropriate vaulted fitting relationship.

The goal is sufficient clearance to avoid clinically meaningful corneal or limbal bearing after the lens has settled.

This is important:

Measure the settled lens – not just the lens five minutes after insertion.

A 2025 keratoconus study comparing 15.0 and 16.5 mm scleral lenses found that more than 50% of total lens settling occurred within the first two hours. [6]

Therefore an apparently generous clearance immediately after insertion can become considerably smaller during wear.

Teaching Point

Always distinguish:

initial clearance

from

settled clearance.

3. Excessive Clearance

Figure 5. Historical image demonstrating excessive sagittal depth and an unnecessarily thick fluid reservoir.

The original page suggested that a large amount of clearance provided:

“more wiggle room for keratoconus progression.”

That statement should be retired.

Excessive clearance is not a safety margin for progression.

A scleral lens does not treat or stabilise keratoconus.

More importantly, increasing the thickness of the post-lens fluid reservoir increases the diffusion distance through which oxygen must travel before reaching the cornea.

Experimental and modelling studies show that scleral lens wear induces a small degree of corneal oedema even in healthy eyes, and the physiological burden becomes more relevant in compromised corneas. [7,8]

A 2026 systematic review and meta-analysis involving 830 eyes found a small but statistically significant increase in central corneal thickness during scleral lens wear. [7]

Therefore the contemporary principle is:

Enough clearance – not maximum clearance.

Particularly in:

post-graft eyes;
compromised endothelium;
very thin corneas;
previous hydrops;
corneal scarring; and
other eyes with reduced physiological reserve.

The Landing Zone – The Lens Does Not Land on a Sphere

The original page correctly recognised:

“Landing Zone is a Tangent with alignment fit.”

Figure 6. Original landing-zone illustration. Contemporary fitting increasingly recognises that the anterior sclera is frequently toric or asymmetric rather than rotationally symmetric.

The sclera is not a billiard ball.

Its shape becomes increasingly non-rotationally symmetric further from the limbus.

Contemporary scleral lens landing zones may therefore be:

spherical;
toric;
quadrant-specific;
multi-meridian;
freeform; or
completely customised from corneo-scleral profilometry.

Why Does This Matter?

Poor landing-zone alignment can cause:

blanching;
conjunctival compression;
edge lift;
tear ingress;
debris accumulation;
lens rotation;
lens flexure;
discomfort; and
decentration.

A 2024 QUT study by Alexander, Aweke, Bhebhe, Collins, Vincent and colleagues demonstrated that toric landing zones reduced:

lens flexure by approximately 62%; and
lens rotation by approximately 77%

compared with a spherical landing zone under the study conditions. [3]

That is a particularly useful paper for QUT students because it experimentally demonstrates why landing-zone geometry matters rather than simply treating toricity as a manufacturer option.

Modern Fitting – From Trial Lens to Ocular Surface Profilometry

The original page advised:

“Use topography just to paint a picture and help determine severity.”

There is still truth in that.

Corneal topography is extremely useful for understanding the central cornea, but traditional Placido topography does not tell us enough about the conjunctival/scleral landing surface.

Modern fitting can incorporate:

anterior-segment OCT;
Scheimpflug tomography;
corneo-scleral profilometry;
image-based lens design;
impression-based fitting; and
freeform or quadrant-specific landing zones.

Image- and impression-guided scleral fitting are increasingly being used to address highly irregular ocular surfaces and difficult landing-zone anatomy. [10]

Systems capable of mapping beyond the limbus can quantify:

scleral toricity;
elevation asymmetry;
limbal geometry;
sagittal height at different chords; and
quadrant-specific landing requirements.

The principle remains:

Measure the surface the lens is actually landing on.

“No Dust Under Scleral Lenses”?

Not quite.

Scleral lenses are extremely stable and can provide excellent protection from the external environment.

However, particulate material can accumulate within the post-lens fluid reservoir.

This phenomenon is known as:

Midday Fogging

Patients typically report:

vision that is initially clear;
progressive haze or clouding after several hours;
temporary improvement after removing, cleaning and refilling the lens.

Material within the reservoir may include:

inflammatory cells;
lipid;
mucin;
epithelial debris; and
other particulate material.

A 2024 prospective study confirmed that midday fogging remains a clinically important problem and investigated associations with lens and filling-solution characteristics. [4]

A separate 2024 laboratory study also suggested that material associated with midday fogging may have pro-inflammatory effects on corneal epithelial cells. [5]

Teaching Point

Do not promise patients:

“Nothing can get under a scleral lens.”

Instead:

A well-fitted lens creates a relatively stable reservoir, but fogging and debris accumulation remain recognised clinical problems.

Optical Performance – Why Scleral Lenses Work So Well

A rigid scleral lens creates a regular anterior optical surface while the fluid reservoir masks much of the irregular anterior corneal shape.

This can substantially reduce:

irregular astigmatism;
coma;
trefoil; and
other anterior corneal higher-order aberrations.

A 2025 systematic review of keratoconus scleral-lens studies found consistent improvements in visual acuity and vision-related quality of life. [2]

However:

Conventional scleral lenses do not necessarily normalise all HOAs.

Residual aberration may arise from:

posterior corneal irregularity;
internal optics;
lens decentration;
lens flexure; and
the relationship between the optical axis and pupil.

A 2025 review by Swartz, Alam, Gentle and Downie discusses these residual optical limitations and the role of customised scleral optics. [9]

Wavefront-guided scleral lenses are now capable of addressing selected residual HOAs.

A 2025 randomised crossover trial demonstrated improved visual performance with wavefront-guided scleral lenses compared with conventional scleral optics in irregular corneal astigmatism. [11]

Even more locally relevant, a 2026 study involving QUT researcher Professor Stephen Vincent demonstrated substantial reductions in HOAs, improvement in contrast sensitivity and symptom improvement after scleral lens fitting in ocular-surface disease. [12]

The Case – Extreme Early-Onset Keratoconus

Clinical Presentation

18-year-old male

with:

advanced bilateral keratoconus;
OS > OD;
previous bilateral acute corneal hydrops;
corneal neovascularisation;
substantial stromal scarring; and
extreme corneal thinning.

Unaided Visual Acuity

OD: counting fingers +
OS: counting fingers −

Historical Central Corneal Thickness

OD: approximately 290 μm
OS: approximately 280 μm

Medication

Patanol BD OU was recorded historically, presumably addressing an allergic/itch component.

In a young keratoconus patient, control of allergy and avoidance of vigorous eye rubbing remain important components of management.

Clinical Appearance

Figure 7. Original slit-lamp image from the case demonstrating severe ectatic corneal disease.

Figure 8. Original clinical image demonstrating advanced corneal distortion and scarring.

Figure 9. Original slit-lamp image demonstrating the severity of the corneal ectasia.

These images demonstrate why this is not simply:

“another keratoconus contact lens fit.”

This is an extremely structurally compromised cornea.

The objectives are:

achieve the maximum useful vision;
avoid additional mechanical corneal trauma;
minimise physiological stress;
control underlying ocular allergy/inflammation;
monitor the ectatic disease; and
determine whether corneal surgery may ultimately be required.

Topography – Useful, but Look at What the Instrument Is Trying to Measure

Figure 10. Historical topography from the case demonstrating the extreme irregularity of the corneal surface.

In a severely distorted, scarred post-hydrops cornea, topography can be difficult to acquire and difficult to interpret.

Placido-disc systems depend upon a sufficiently regular reflected mires pattern.

With:

severe ectasia;
dense scarring;
neovascularisation;
tear-film disruption; and
extreme surface irregularity,

the map may contain substantial missing or unreliable data.

Teaching Point

Do not confuse:

“The machine produced a colourful map”

with

“Every data point is reliable.”

This is exactly where tomography, OCT and direct sagittal assessment become particularly useful.

Historical Scleral Lens Parameters

The original lenses were recorded as:

Right Eye

Gelflex scleral lens – Harmony Plus

7.00 / 12.50 / 15.25 / 18.50 / −7.25

Centre thickness: 220 μm
Sag: 5857 μm
VA: 6/12=

Left Eye

7.35 / 12.50 / 15.25 / 18.50 / −5.25

Centre thickness: 220 μm
Sag: 6178 μm
VA: 6/15=

These are historical lens parameters and should not be interpreted as a current fitting guide.

What they demonstrate beautifully is the magnitude of the optical rehabilitation.

From Counting Fingers to 6/12 and 6/15

This is the headline result.

Right Eye

CF+ → 6/12=

Left Eye

CF− → 6/15=

That is an enormous functional visual improvement despite:

advanced ectasia;
previous hydrops;
severe thinning;
stromal scarring; and
neovascularisation.

The residual acuity limitation is not surprising.

A scleral lens can mask anterior corneal irregularity.

It cannot remove:

stromal scar;
optical opacity;
posterior corneal irregularity;
retinal pathology;
amblyopia from early-onset poor vision; or
every residual HOA.

Teaching Point

In severe keratoconus:

6/12 can be a spectacular result.

Do not judge success solely against an arbitrary target of 6/6.

Compare performance with:

previous visual function;
occupational requirements;
binocular function;
contrast sensitivity;
quality of life; and
the realistic optical potential of the eye.

Why Does the Left Eye Need More Sag?

The historical sagittal heights were:

OD: 5857 μm

OS: 6178 μm

Difference:

321 μm

This is clinically meaningful.

The left eye was described as the more severe ectatic eye.

A greater ocular sagittal height over the same functional chord requires a greater lens sagittal depth to provide an equivalent vaulted relationship.

This is a much more useful way of thinking than simply saying:

“The left K is steeper.”

The entire ocular surface geometry determines the required lens architecture.

Lens Diameter – 18.50 mm

An 18.50-mm lens creates a very different fitting platform from a small corneal GP.

Potential advantages include:

a large bearing footprint;
excellent stability;
broad corneal and limbal vault;
large optical zone;
reduced likelihood of lens displacement; and
distribution of load across a wider conjunctival area.

But increasing diameter also means the landing zone encounters more peripheral scleral asymmetry.

Consequently larger lenses frequently require:

toric landing zones;
quadrant-specific landing zones;
notches;
microvaults;
freeform designs; or
profilometry-derived haptics.

Bigger is not automatically better.

Lens diameter is a design variable, not a measure of fitting quality.

The Very Thin Cornea – 280–290 μm

This feature deserves special attention.

These values represent extreme corneal thinning.

In 2026, a student should immediately recognise that standard epithelium-off CXL protocols historically required substantially greater stromal thickness because of concern regarding endothelial UVA exposure.

Does This Mean CXL Is Impossible?

Not necessarily.

Modern thin-cornea approaches include:

contact-lens-assisted CXL;
hypo-osmolar swelling protocols;
epithelial-island techniques;
customised fluence;
Sub-400 protocols; and
other specialist approaches.

Recent studies have extended CXL treatment into significantly thinner corneas. [14]

However, a 280–290 μm scarred post-hydrops cornea is not a routine CXL case.

The decision must consider:

whether progression remains demonstrable;
stromal thickness;
scar location;
endothelial health;
previous hydrops;
neovascularisation;
visual potential; and
whether transplantation is becoming the more appropriate intervention.

Do Not Confuse Optical Rehabilitation With Disease Stabilisation

The scleral lens provides vision.

It does not stabilise the biomechanical disease.

Acute Corneal Hydrops

Figure 11. Acute corneal hydrops in advanced keratoconus, demonstrating marked stromal oedema following disruption of the posterior corneal complex.

Acute corneal hydrops occurs when a break in Descemet membrane/posterior corneal tissue allows aqueous to enter the corneal stroma.

The result may include:

sudden visual deterioration;
marked stromal oedema;
epithelial oedema;
photophobia;
pain;
corneal thickening;
subsequent stromal scar; and
neovascularisation.

This patient’s previous bilateral hydrops is a marker of very advanced ectatic disease.

A contemporary 2024 review describes an expanding range of management strategies, including conservative treatment and interventions intended to accelerate resolution by addressing the posterior corneal break. [13]

Importantly

Acutely hydrops-affected eyes are not simply fitted immediately with a scleral lens.

The acute episode must first be appropriately managed and the cornea allowed to reach a sufficiently stable state.

Hydrops Can Sometimes Improve Contact Lens Optics – But at a Cost

Following resolution of hydrops, stromal scarring can sometimes result in relative flattening of an extremely steep cone.

This may paradoxically make subsequent contact lens fitting easier.

But this should never be interpreted as a beneficial event.

The trade-off can include:

permanent stromal opacity;
reduced transparency;
neovascularisation;
irregular posterior corneal optics; and
reduced maximal visual potential.

Midday Fogging – Especially Relevant in a Large Reservoir

In a lens such as this, students should actively ask:

Does vision deteriorate after several hours?
Does the reservoir become turbid?
Is the lens excessively loose?
Is there tear exchange carrying debris underneath?
Is the lens excessively tight with trapped inflammatory material?
Is there ocular allergy?
Is there significant meibomian gland dysfunction?
Is the filling solution appropriate?

Do not treat midday fogging as a single diagnosis with a single solution.

It is a clinical sign with multiple possible mechanisms. [4,5]

Oxygen – Particularly Important in This Case

The corneas in this case are not normal.

They are:

extremely thin;
previously hydrops-affected;
scarred; and
vascularised.

That makes physiological fitting particularly important.

Variables affecting oxygen delivery include:

lens material Dk;
lens centre thickness;
fluid reservoir thickness;
lens diameter;
tear exchange;
endothelial function; and
duration of wear.

The Old Approach

“Clear it by as much as possible.”

The Contemporary Approach

“Use the minimum clearance compatible with complete corneal and limbal vault after settling.”

Recent QUT research has demonstrated measurable central and peripheral corneal oedema during scleral lens wear and provides further physiological evidence against unnecessary reservoir thickness. [8]

What About Neuropathic Corneal Pain?

The original page listed:

Corneal hyperalgesia / corneal neuropathic pain

as a major scleral-lens indication.

This requires more nuance in 2026.

Corneal neuropathic pain is characterised by altered nociceptive processing and can involve:

peripheral sensitisation;
central sensitisation; or
both.

Symptoms may be dramatically disproportionate to conventional ocular-surface signs.

Scleral lenses can be helpful in selected patients by:

shielding the corneal surface from airflow;
reducing environmental stimulation;
maintaining a liquid reservoir; and
protecting compromised epithelium.

However:

A scleral lens is not a universal treatment for neuropathic corneal pain.

Some patients with marked hyperalgesia may be unable to tolerate any lens.

Patients with a strong central pain component may derive little benefit from simply protecting the ocular surface.

The 2024 review by Watson and Le provides an excellent contemporary framework for understanding peripheral versus central corneal neuropathic pain. [15]

This topic is better explored separately from the severe keratoconus case rather than treating all ocular pain as another simple indication for a scleral lens.

Lens Application – The Reservoir Matters

A scleral lens must be inserted completely filled with an appropriate sterile, preservative-free filling solution.

Incomplete filling can create bubbles.

Bubbles can produce:

localised corneal desiccation;
variable vision;
focal discomfort; and
an incorrect assessment of the fitting relationship.

Do Not Use Tap Water

Tap water should never be used to:

fill;
rinse;
wet; or
store scleral contact lenses.

Appropriate disinfection and hygiene are essential, particularly in severely compromised corneas.

Post-Removal Examination

Never judge the fit only while the lens is on the eye.

After removal assess:

corneal staining;
limbal staining;
conjunctival compression;
blanching;
rebound hyperaemia;
epithelial bogging;
conjunctival prolapse;
oedema;
impression rings; and
vascular response.

A lens can look beautifully centred and still be physiologically poor.

What Would I Measure If This Patient Presented in 2026?

1. Corneal Structure

Obtain the best possible:

tomography;
pachymetry;
anterior-segment OCT;
epithelial imaging where possible;
endothelial assessment; and
slit-lamp documentation.

2. Disease Stability

At only 18 years of age, establish whether progression is continuing.

Do not infer stability from:

good contact-lens vision;
previous hydrops; or
one stable Kmax value.

3. The True Ocular Sag

Measure sagittal height over an appropriate chord.

Where available, use corneo-scleral profilometry to understand the entire surface rather than extrapolating scleral shape from corneal topography.

4. Initial and Settled Clearance

Use anterior-segment OCT.

Measure:

central clearance;
clearance over the cone apex;
minimum corneal clearance;
limbal clearance; and
change after settling.

5. Landing-Zone Alignment

Assess every quadrant.

Look for:

compression;
impingement;
edge lift;
blanching;
tear ingress;
rotation;
decentration; and
focal interaction with conjunctival anatomy.

6. Optical Performance

Measure more than high-contrast acuity.

Include:

contrast sensitivity;
ghosting;
monocular diplopia;
low-contrast VA;
mesopic performance;
glare;
subjective visual quality; and
binocular function.

7. Reservoir Quality

Reassess after several hours.

Look for:

midday fogging;
bubbles;
particulate matter;
front-surface deposits; and
changes in VA.

8. Corneal Physiology

Particularly in this extreme case, assess:

pre- and post-wear pachymetry where indicated;
oedema;
endothelial status;
neovascularisation;
corneal staining; and
maximum tolerated wearing time.

Clinical Take-Home Points

Think sagittal depth over a defined chord – not base curve alone.
Modern scleral lens terminology is based primarily on tissue bearing, not arbitrary diameter categories.
An 18.5-mm lens should not automatically be called “mini-scleral”.
Complete corneal vault does not mean maximum corneal vault.
Excessive fluid reservoir thickness is not a safety margin for future keratoconus progression.
Scleral lenses do not treat or stabilise keratoconus.
Allow for lens settling before declaring the central and limbal clearance acceptable.
The sclera is not rotationally symmetric. Toric and customised landing zones can materially improve lens behaviour.
QUT research demonstrates that toric landing zones reduce scleral lens flexure and rotation.
Midday fogging is real. Scleral lenses do not create a debris-free sealed environment.
A thicker reservoir is an oxygen burden. This becomes particularly important in compromised corneas.
A 280–290 μm post-hydrops cornea is an extreme case. CXL decisions require specialist thin-cornea protocols and cannot be approached as routine Dresden-protocol treatment.
CF to 6/12 can represent extraordinary visual rehabilitation. Do not define success as 6/6.
Topography becomes less reliable as corneal irregularity and scarring become extreme.
OCT and corneo-scleral profilometry are increasingly important for advanced fitting.
Corneal neuropathic pain is not synonymous with dry eye and not every patient with neuropathic pain will tolerate or benefit from a scleral lens.
Inspect the eye after lens removal. A visually successful fit can still be physiologically poor.
Treat the cornea, the optics and the disease process as three separate clinical problems.

Peer-Reviewed Reading – QUT Master of Optometry

1. Michaud L, Lipson M, Kramer E, Walker M. The official guide to scleral lens terminology. Cont Lens Anterior Eye. 2020;43(6):529–534. doi:10.1016/j.clae.2019.09.006. PMID: 31561849.

2. Mushtaq A, Alvi I. Long-Term Effectiveness of Scleral Lens Treatment in the Management of Keratoconus: A Systematic Review. Cureus. 2025;17(1). doi:10.7759/cureus.77102. PMID: 39781287.

3. Alexander J, Aweke YB, Bhebhe Z, Cho D, Lay S, Ryan I, Collins MJ, Vincent SJ. The effect of landing zone toricity on scleral lens fitting characteristics and optics. Ophthalmic Physiol Opt. 2024;44(5):867–875. doi:10.1111/opo.13324. PMID: 38699941.

4. Fogt JS, et al. Lens and solution properties in patients with and without midday fogging. Ophthalmic Physiol Opt. 2024;44(4):769–773. doi:10.1111/opo.13293. PMID: 38404141.

5. Walker MK, Lema C, Redfern R. Potential pro-inflammatory impact of scleral lens midday fogging on human corneal epithelial cells: An in vitro study. Cont Lens Anterior Eye. 2024;47(5):102187. doi:10.1016/j.clae.2024.102187. PMID: 38762441.

6. Vurgun EB, Turhan SA, Toker AE. Size Matters: A Comparative Study on Midday Fogging and Lens Settling in Patients With Keratoconus Wearing Mini-Scleral Lenses With Two Different Diameters. Eye Contact Lens. 2025;51(2):53–57. doi:10.1097/ICL.0000000000001135. PMID: 39773920.

7. Corneal and Intraocular Pressure Responses to Scleral Lens Wear: A Meta-Analysis. 2026. PMID: 42228331.

8. Iqbal A, Fisher D, Alonso-Caneiro D, Collins MJ, Vincent SJ. Central and peripheral scleral lens-induced corneal oedema. Ophthalmic Physiol Opt. 2024;44(4):792–800. doi:10.1111/opo.13221. PMID: 37622425.

9. Swartz G, Alam K, Gentle A, Downie LE. Impact of contact lens correction on wavefront aberrations and vision quality in keratoconus. Ophthalmic Physiol Opt. 2025;45(7):1811–1828. doi:10.1111/opo.70037. PMID: 41159562.

10. Image- and impression-based technology for scleral lens fitting for keratoconus: Efficiency of the fitting process. Cont Lens Anterior Eye. 2024;47:102174. doi:10.1016/j.clae.2024.102174. PMID: 38693011.

11. Gelles JD, Su B, Kelly D, et al. Visual Improvement With Wavefront-Guided Scleral Lenses for Irregular Corneal Astigmatism. Eye Contact Lens. 2025;51(2):58–64. doi:10.1097/ICL.0000000000001152. PMID: 39661442.

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